Symposium Organizers
Piotr Grodzinski National Cancer Institute
Scott Manalis Massachusetts Institute of Technology
Sonke Svenson Cerulean Pharma Inc.
Xing-Jie Liang National Center for Nanoscience and Technology of China
Wenbin Lin University of North Carolina-Chapel Hill
JJ1: Detection of Biomarkers and Biological Response
Session Chairs
Monday PM, November 28, 2011
Room 203 (Hynes)
10:00 AM - **JJ1.1
Nanotheranostics for Cancer: Targeted Nanoparticles for Tumor Imaging, Image-Guided Drug Delivery and Light Induced Therapy.
Paras Prasad 1 2 , Tymish Ohulchanskyy 1
1 Institute for Lasers, Photonics and Biophotonics, State University of New York at Buffalo, Buffalo, New York, United States, 2 Chemistry, State University of New York at Buffalo, Buffalo, New York, United States
Show AbstractFor cancer therapy, nanoparticles provide a platform combining multimodal diagnostics (e.g., medical imaging) with multipronged therapy. The talk will provide examples of our efforts in designing multifunctional nanoparticles of ceramic, polymeric, semiconductor and metallic composition, for applications in diagnostics and therapy of cancer. The biocompatible or biodegradable nanomaterials, such as polymeric nanomicelles and nanoparticles, heavy metal-free quantum dots (silicon nanocrystals), fluoride nanocrystals, magnetic (iron oxide) and plasmonic (gold) nanoparticles, and their combination, will be discussed. The composition, porosity and surface properties of the nanoparticles have been tailored to enable targeted and image-guided drug delivery and/or light-activated therapy. Multimodal nanoplatforms containing multiple imaging and sensing probes have been developed, which will enable the integration of imaging/sensing at the cellular, tissue and whole-body level using a single formulation. Our recent results on nanoparticle mediated gene-silencing for overcoming the inherent radio/chemo-resistance of cancer cells will be also presented. Incorporation of both diagnostic (multimodal imaging) and therapeutic payload within a single nanoplatform have provided the ability for triggering on-demand therapy, along with monitoring the efficacy of treatment in real-time. This talk will conclude with a discussion of examples of new challenges and opportunities in these fields. 1.P.N.Prasad, “Introduction to Biophotonics”, Wiley Interscience, New York (2003).2.P. N. Prasad “Nanophotonics”, John Wiley & Sons, New York (2004).3.P. N. Prasad “Inroduction to Nanomedicine and Nanobioengineering”, to be published by John Wiley & Sons.
10:30 AM - JJ1.2
Novel Multifunctional Nanocarriers Capable of In Vivo Rapidly Controlled Drug Release for MR Imaging and Targeted Epilepsy Therapy.
Hsin-Yang Huang 1
1 Department of Materials Sciences and Engineering, National Chiao Tung University, Hsin Chu, TAIWAN, Taiwan
Show AbstractThermosensitive nanocarrier were synthesized by incorporation of iron oxide nanoparticles (NPs) and hydrophobic drug molecules into the negative thermosensitive matrix composed of PEO-PPO-PEO (F127) and the H-bond provider of PVA via mini-emulsion process. The developed novel drug-delivery vectors capable of achieving remotely triggered burst drug release in vivo in a few seconds, which is very important for chronic disease needed to be treated in a short time such as epilepsy. Under exposure to high frequency magnetic field (HFMF), heat was generated from the iron oxide NPs in the carriers, leading to an immediate deformation of hydrogen bonds as well as rapid collapse of the nanostructure, in which a large amount of imbibed drug can be rapidly released out in the real time. However, in the absence of the HFMF, the nanocarriers displayed a relatively stable morphology without any leakage and showed low drug release rate, indicating the drug molecules remained well in the matrix. In this in vivo study, an anti-epilepsy drug, ESM (ethosuximide), was encapsulated in this magnetically-thermal sensitive nanocarrier. While subjecting to HFMF in few seconds, it was found that the ESM was burst released from the carrier in the Long-Evans rat model, which has demonstrated a significant reduction in spike-wave discharge, indicating the potential application of the drug-carrying magnetic carriers as the building blocks that ensure a rapid and precise response to magnetic stimulus. The nanocarriers are also shown to be good candidates for magnetic resonance imaging (MRI) contrast agents as demonstrated by the high r2/r1 ratio (438) with long-term stability under magnetic field. Together with well-regulated controlled release design and the MRI, the nanocarrier not only shows clear MR image of acute epilepsy nodus, but also latent one. Based on this preliminary study, the investigation of multifunctional nanocarriers for in vivo controlled drug release combining with imaging and targeted therapy is now in progress in our group and will be reported in this meeting.
10:45 AM - JJ1.3
``AND'' Logic T1-T2 Nanoparticles for Fault-Free MR Imaging.
Jin-sil Choi 1 , Tae-hyun Shin 1 , Dongwon Yoo 1 , Ho-Taek Song 2 , Eung Yeop Kim 2 , Jinwoo Cheon 1
1 Dept. of Chemistry, Yonsei University, Seoul Korea (the Republic of), 2 Department of Radiology , College of Medicine, Yonsei University, Seoul Korea (the Republic of)
Show AbstractAccuracy in the diagnostics is one of the critical issues in biomedical sciences because it affects on the decision of the medical treatment processes and determines the survival rate of the patient. Devising dual imaging tools in single imaging system would be an attractive way to pursue. In particular, for MRI, to enhance imaging accuracy, two different imaging modes with specific contrast agents are being used; one is T1 type which generates “positive” signal enhancements and the other one of T2 type which gives “negative” signal enhancements. When present together, these contrast agents can potentially provide highly sensitive and valuable complementary diagnostic information in real time by simply switching the scanning mode in MRI. However, the realization of such a contrast agent with well-defined T1 and T2 capabilities has been difficult because T1 signal is strongly quenched by T2 agent when they are combined together. Here, we demonstrate the design and systematic construction of an innovative T1-T2 dual modal nanoparticle contrast agent which exhibits simultaneously strong T1 and T2 signal enhancements. Developed nanoparticles can have “AND” logic where imaging area with both T1 and T2 signals satisfy the “AND” and self-confirms the validity of the results from each imaging mode. We also show that a variety of new type of dual mode contrast agents can be obtained by the combinations of different T1 and T2 nanomaterials.
11:00 AM - JJ1.4
Quantum-Dot-Decorated Enzyme Nanocapsules for Cancer Imaging and Therapeutics.
Juanjuan Du 1 , Ming Yan 1 , Titiana Segura 1 , Yi Tang 1 , Yunfeng Lu 1
1 Department of Chemical and Biomolecular Engineering, UCLA, Los Angeles, California, United States
Show AbstractCancer is a leading cause of death worldwide. Developing safe and efficient cancer therapy has long been pursued by scientists and doctors. In this context, a combination of therapeutics with imaging, which potentially eliminates the unnecessary treatments and provides means to monitor treatments, could result in significant increased drug efficacy and safety. Our work presented here, based on a quantum-dot-decorated enzyme nanocapsule (QDEN) structure, integrates bioluminescence imaging with enzyme-targeted prodrug therapy, providing a prototype for combined cancer diagnostics and therapeutics. The fabrication of QDEN is simple and biomolecule-compatible. Using aqueous in-situ polymerization on bioluminescent enzyme horseradish peroxidase (HRP) anchored with polymerizable vinyl groups, we obtained nano-sized core-shell nanocapsules with enzyme as the core and crosslinked thin polymer net as the shell. HRP in the core of QDENs, together with indole-3-acetic acid, is also proposed as a prodrug cancer therapy agent. The resulted nanocapusles possess greatly enhanced stability, retained bioactivity, and readily engineered surface. In particular, by incorporating polymerizable amines in the polymerization, we endowed the nanocapsules with efficient cell-transduction and sufficient conjugation sites for follow-up modification. Following in-situ polymerization, decorating the polymer shell with fluorescent quantum dots allowed us to access continuous tunable wavelength, which extends the application of such bioluminescent nanocapsules, especially in deep tissue. In addition, the unique core-shell structure and adequate conjugation sites on surface enabled us to maximize the BRET efficiency by adjusting the QD/enzyme conjugation ratio. Additional functionalization of surface with targeting modality features the QDENs with cancer targeting capabilities, enabling the potential applications of QDENs as cancer imaging and therapeutic agents.
11:30 AM - **JJ1.5
Magnetic Nanoparticles for Theranostics and Cell Actuations.
Jinwoo Cheon 1
1 , Yonsei University, Seoul Korea (the Republic of)
Show AbstractOne of the important trends of next-generation nanomedicine is theranostics that is defined by the combination of therapeutics and diagnostics on a single platform. Magnetic nanoparticles are among one of the most essential platforms for targeted imaging, therapy, and simultaneous monitoring of therapeutic efficacy. In this talk, I will discuss magnetic nanoparticles as a core platform material for theranostics and add a variety of functionalities such as drug, targeting moiety, and gene to enhance their performance. Their unique utilization in highly accurate dual-modal MR imaging, therapeutic hyperthermia of cancer cells, controlled drug release, and molecular level cell signaling and cell fate control will be discussed.
12:00 PM - JJ1.6
Magnetic Nanoparticles as MRI Contrast Agents and for Selective Targeting of Cells.
Wolfgang Tremel 1 , Thomas Schladt 1 , Bahar Nakhjavan 1 , Kerstin Koll 1 , Heiko Bauer 1 , Oskar Koehler 1 , Isabell Schick 1 , Anna Schilmann 1 , Muhammad Tahir 1 , Filipe Natalio 1 , Peter Bluemler 2 , Kerstin Muennemann 3
1 Institut für Anorganische Chemie, Johannes Gutenberg-Universität, Mainz Germany, 2 Institut für Physik, Johannes Gutenberg-Universität, Mainz Germany, 3 , Max Planck-Institut für Polymerforschung, Mainz Germany
Show AbstractOne of the goals for biomedical applications of nanoparticles is their functionalization to impart precise biological functions. Nanomaterials can be loaded with low molecular drugs or large molecules like ribonucleic acids (RNA) which are inherently difficult to deliver due to their size and polarity. Nanoparticles are attractive probe candidates because of their (i) size and surface-to-volume ratio, (ii) tunable physical properties directly related to size, composition, and shape, (iii) unusual target binding properties, and (iv) structural robustness. We have developed biocompatible materials by surface functionalization of MnO nanoparticles using polymers or porous silica coatings that simultaneously (i) carry ligands (poly(I:C), CpG, etc.) and (ii) large target molecules (e.g. antibodies for target detection), (iii) small molecules (e.g. drugs) through non-specific binding, and (iv) fluorophors for optical detection. (v) In addition, the nanoparticles can be traced using magnetic resonance imaging (MRI) by virtue of the magnetic properties. Cytotoxicity was evaluated by an electric cell-substrate impedance sensing (ECIS) micromotion assay. The ssDNA and CpG coupled nanoparticles were used to target Toll-like receptors (TLR3 and TLR9) receptors inside the cells and to activate the classical TLR cascade. The multimodal nanoparticles allow optical as well as MRI imaging of cellular trafficking. For in vivo MRI imaging, the water-dispersible functionalized MnO nanoparticles were injected into the tail vene of nude mice. The MnO nanoparticle contrast-enhanced T1-weighted MRI showed contrast-enhanced regions following accumulation of MnO nanoparticles in the tumor.In addition, Janus-type (M-1)@(M-2 oxide) (M-1: Au, Ag, Cu, Pt, Rh, Co and Fe/Pt); M-2: MnO, Fe3O4) were synthesized by thermal decomposition of metal salts in the presence of metal colloids. In particular, the surface chemistry of both domains can be functionalized independently, where tumor cells were addressed by conjugated antibodies, CpG ligands were attached for immunotherapy and an effective killing of the cells could be achieved under illumination with NIR light. Depending on the chemical anisotropy Janus particles can form superamphiphiles or giant dipoles producing particles with unprecedented properties. The new properties are of considerable interest due to their substantial membrane activity.
12:15 PM - JJ1.7
Modulating the Luminescence of Upconverting Nanoparticles Using Dithienylethene Photoswitches for Biolabeling Applications.
John-Christopher Boyer 1 , Carl-Johan Carling 1 , Neil Branda 1
1 Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
Show AbstractPhotoactivatable fluorophores are powerful tools for increasing the temporal and special resolution in bioimaging. Upconverting nanoparticles (UCNPs) possess several properties that make them ideal for use as biolabels including increased photostability, absence of blinking, and low excitation densities but have yet to be designed for microscopic photoactivation. At the same time the use of dithienylethene (DTE) photoswitches to achieve control of physical and chemical molecular properties has been well documented in recent years. Through the combination of upconverting nanoparticles (UCNPs) and DTE photoswitches we are able to create photomodulated upconverting biolabels. Using the absorption of the DTE photoswitch we are able to selectively quench the luminescence of the UCNP. By modulation the switch with UV and visible light we are able to selectively turn off and on the upconversion luminescence respectively. Our system has an advantage over caged fluorophores as the luminescence of our UCNPs can be cycled through the on and off state multiple times.
12:30 PM - JJ1.8
Incorporation of Quantum-Dots with Mesoporous Silica Nanoparticles for Intracellular Targeting and In Vivo Images.
Po-Jung Chen 1 , Shang-Hsiu Hu 2 , San-Yuan Chen 3 , Dean-Mo Liu 4
1 , National Chiao Tung University, Hsinchu Taiwan, 2 , National Chiao Tung University, Hsinchu Taiwan, 3 , National Chiao Tung University, Hsinchu Taiwan, 4 , National Chiao Tung University, Hsinchu Taiwan
Show Abstract In this study, a nanosystem is constructed using facile technology by embedding different-sized hydrophobic quantum dots (QDs) into mesoporous silica nanoparticles which pore size distribution is 5 nm in radius, and lipid-PEG2000-COOH coated to be encoded with cRGD targeting peptide through biotin-streptavidin bridges. Their novel optical properties render these highly luminescent QDs ideal fluorophores for wavelength-and-intensity multiplexing, and through hydrophobic interaction between the hydrocarbon and TOPO molecules to stabilized QDs in the porous nanobeads. In the solvents (eg., water, ethanol and butanol), none of QDs can be leaked from the porous nanobeads. Furthermore, the QDs tagged mesoporous silica nanoparticles show clearly images sensing not only in vitro but also in vivo of the nude mice. The cRGD-encode lipid coated QDs tagged nanobeads (cRGD-encoded LQNPs) show significantly increased αvβ3-expressing cell targeting in MCF-7 breast cancer cells over than αvβ3-low expressing HeLa cervix cancer cells, which is confirmed by confocal laser scanning microscopy and flow cytometry. In addition, the QNPs also demonstrated fairly high cell viability comparing to free 3-mercaptopropionic acid (MPA)-functionalized QDs. The cRGD-encoded LQNPs introduced here represent a new platform for nanoparticulate multimodality αvβ3-specific response bioimaging agents.
JJ2: Imaging and In-vivo Detection Using Nanoparticles
Session Chairs
Monday PM, November 28, 2011
Room 203 (Hynes)
2:30 PM - **JJ2.1
Multiplex Wash-Free Magneto-Nanosensors for Cancer Diagnostics and Drug Development.
Shan Wang 1
1 Materials Science and Engineering, Stanford University, Stanford, California, United States
Show AbstractReproducible and multiplex protein assays are greatly desired by cancer biologists as well as clinical oncologists to rapidly follow numerous proteins in clinical samples. This will allow physicians to determine the efficacy of relevant chemotherapy in real time or to detect cancer early, e.g., stage 1 ovarian cancer, so that cancer survival rates can be improved greatly. We have now successfully applied magneto-nano biochips based on giant magnetoresistance (GMR) spin valve sensor arrays and magnetic nanoparticle labels (nanotags) to the detection of biological events in the form of multiplex protein assays (4-to 64-plex) with great speed (30 min. – 2 hours), sensitivity (1 picogram/milliliter concentration levels or below), selectivity, and economy [1-3].More recently, we achieved the first demonstration of a nanolabel-based technology capable of rapidly isolating cross-reactive antibody binding events in a highly multiplex manner. By combining magnetic nanotechnology with immunology, we have devised an easy to use and rapid auto-assembly assay which is ideal for high-density screens of aberrant protein binding events [4]. Such a technology has the potential to revolutionize the current practices in the proteomics and drug development community by providing researchers with the tools to rapidly investigate both on and off-target protein binding events. Furthermore, this technology is more sensitive and specific than label-free technologies (e.g., Surface Plasmon Resonance (SPR) based approaches such as Biacore), can be scaled up more readily, and consumes far less valuable reagents [5].References: [1] Gaster RS, Hall DA, et al., Nature Medicine, 15, 1327-1332, 2009.[2] Osterfeld SJ, Yu H, et al., PNAS, 105, 20637-20640, 2008.[3] Hall DA, Gaster RS, et al., Biosensors and Bioelectron., 25, 2051-2057, 2010.[4] Gaster RS, Hall DA, Wang SX, Nano Letters, published online, DOI: 10.1021/nl1026056.[5] Gaster RS et al., Nature Nanotechnology, 6, 314-320, 2011.
3:00 PM - JJ2.2
Quantitative Analysis of Multiple Urinary Biomarkers of Carcinoid Tumors through Gold-Nanoparticle-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry.
Tsung-Rong Kuo 1 4 , Jinn-Shiun Chen 2 , Yu-Chen Chi 1 , Chia-Yi Tsai 3 , Cho-Chun Hu 3 , Chia-Chun Chen 1 4
1 Chemistry, Natl Taiwan Normal University, Taipei Taiwan, 4 Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei Taiwan, 2 Division of Colorectal Surgery, Chang Gung University, Taoyuan Taiwan, 3 Natural Science Education, National Taitung University, Taitung Taiwan
Show AbstractIn this work, a simple technique for quantitative analysis of four urinary biomarkers, tryptophan, 5-hydroxytryptophan, 5-hydroxytryptamine and 5-hydroxyindole acetic acid of carcinoid tumors is developed using gold nanoparticles as the assisted matrix in surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS). The optimal SALDI conditions for the efficient ionization of those biomarkers are systematically explored by the adjustments of the concentrations of gold nanoparticles and internal standards. The calibration curves of the biomarker concentrations are determined using SALDI-TOF MS and the high linearity is obtained in all samples. For future clinical testing, multiplexed detection of those biomarkers in the urine samples of healthy males is performed. The successful quantitative detections of those biomarkers indicate that our technique provides a rapid and accurate platform for clinical screening of carcinoid tumors.
3:15 PM - JJ2.3
High-Performance Electrochemical Sensing of Cancerous Protease (Legumain) Using Nanoelectrode Arrays.
Lateef Uddin Syed 1 , Luxi Zhang 1 , Allan Prior 1 , Jianwei Liu 1 , Duy Hua 1 , Jun Li 1
1 Chemistry, Kansas State University, Manhattan, Kansas, United States
Show AbstractGlobally, thousands of lives are lost every day from various types of cancers. The best way of preventing these deaths is early diagnosis and effective treatment. It is well known that overexpression of certain enzymes such as kinases, phosphatase, and proteases causes cancers. Legumain (also known as asparaginyl endopeptidase) is a lysosomal cysteine protease whose activity is found in several tissues. Legumain is found highly expressed in a majority of tumors including carcinomas of the breast, colon, and prostate, and in central nervous system neoplasms. However, overexpression is not found in normal cells. Legumain is present intracellularly in endosome/lysosome systems and extracellularly in tumor microenvironment, consequently making it a potential cancer biomarker. It has also been reported that legumain specifically cleaves asparaginyl carbonyl bond. Nanostructured carbon materials have attracted extensive attention for various electroanalytical applications, particularly in the form of nanoelectrodes. In the present study, we employed embedded vertically aligned carbon nanofiber (VACNF) nanoelectrode array (NEA), where only the ends of carbon nanofibers (CNFs) are exposed at the surface of the insulating SiO2 matrix. The exposed CNF tips were functionalized with an electroactive ferrocene (Fc)-linked tetrapeptide (Ala-Ala-Asn-Leu-Fc). The asparagine site (C-terminus) of the tetrapeptide is cleaved by legumain, which results in the release of Fc moieties from the electrode to the bulk solution, leading to a drastic decrease in the electrochemical signal. Towards achieving this goal, as a first step to understand the electron transfer phenomenon at the CNFs, the exposed CNF tips were functionalized with Fc moieties and a careful electrochemical investigation of electron transfer rate (ETR) with direct current (DC) and alternating current (AC) voltammetric techniques was carried out. Our results show striking difference in ETR between DC and AC voltammetric measurements, revealing an anomalous phenomenon of electron transfer at CNF NEAs that is likely defined by the intrinsic properties of CNFs rather than the faradaic process at the electrode surface. We observed 100 times higher ETR by AC voltammetry than by DC voltammetry. The electrochemical properties of the nanoelectrode were found to critically depend on the unique conical graphitic stacking of the CNFs, which facilitates a new capacitive pathway in high-frequency AC voltammetric measurements. This study indicates that selecting an appropriate electrochemical technique can cope with the intrinsic limit of nanoelectrode materials. Particularly, high-frequency AC voltammetry can provide high-performance nano-biosensors and nanoelectronics with CNF NEAs. These findings are being utilized to build an ultrasensitive legumain biosensor for electrochemical monitoring of legumain activity in various cancerous cell lines.
3:30 PM - JJ2.4
Investigating Receptor-Ligand Interactions on Tunable Nanostructured, Biofunctionalized Surfaces under Flow.
Sebastian Kruss 1 2 , Luise Erpenbeck 3 , Michael Schoen 3 , Joachim Spatz 1 2
1 , MPI for Intelligent Systems, Stuttgart Germany, 2 Physical Chemistry, Heidelberg University , Heidelberg Germany, 3 Department of Dermatology, Göttingen University, Heidelberg Germany
Show AbstractThe interaction of cells in the bloodstream with vascular endothelial cells is crucial for many physiological and pathological processes within the organism, inflammation and hematogenous cancer metastasis being the most prominent examples. In the past decades, many approaches have been taken to unravel these complex mechanisms. However, in vivo investigation of single receptor-ligand interactions can be difficult due to the high complexity of these model systems. In vitro models, on the other hand, also have severe limitations as they often do not allow simultaneous control of biophysical parameters such as shear rate, receptor density or clustering. For this reason, our goal was to design a flow chamber system which is based on the “classical” parallel plate flow chamber while allowing a precise modulation of said biophysical parameters. To design surfaces with precisely tunable densities of biomolecules, nanopatterns of 6 nm gold nanoparticles were created by self-assembly of diblock copolymer micelles on glass substrates. The distance between gold nanoparticles can be adjusted, ranging from 25 nm to 250 nm. Furthermore, clustering effects and density gradients can be mimicked. Biomolecules such as different selectins or selectin receptors can then be bound to the gold nanoparticles in a site directed manner. In contrast to conventional protein-adsorption methods on surfaces, this ensures biologically correct presentation of the binding epitopes. The glass substrates can then be integrated into a flow chamber system in which hydrodynamic parameters can be controlled. Interaction of cells of the blood stream such as leukocytes and tumor cells or of beads presenting only a certain kind of ligand can then be surveyed. This novel approach to investigate ligand-receptor interactions allows the determination of important biophysical parameters of said interactions, such as maximum and minimum shear rates needed for receptor interactions, shear and ligand density thresholds as well as life-times of the interaction.
3:45 PM - JJ2.5
Exploring the Impact of Cell Mechanics on Cancer Progression with the Microfluidic Optical Stretcher.
Mareike Zink 1 , Franziska Wetzel 1 , Anatol Fritsch 1 , Steve Pawlizak 1 , Tobias Kiessling 1 , Kenechukwu Nnetu 1 , Lars-Christian Horn 2 , Michael Hoeckel 3 , Josef Kaes 1
1 Soft Matter Physics Division, University of Leipzig, Leipzig Germany, 2 Institute of Pathology, University of Leipzig, Leipzig Germany, 3 Department of Obstetrics and Gynecology, University of Leipzig, Leipzig Germany
Show AbstractBiophysics established a new research area which described the progression of cancer from a materials science perspective. It has been know for a long time that malignant transformation is associated with significant changes in the cellular cytoskeleton. If the cytoskeleton’s alterations are necessary for malignant transformation, they have to trigger biomechanical changes that impact cellular functions. The Microfluidic Optical Stretcher (MOS) is a fully automatic technique to marker and contact-free probe the mechanical properties of cells with a through-put of several hundred cells per hour. Since cytoskeletal properties such as actin concentration are non-linearly correlated with the shear modulus of the cell and changes are amplified up to the power of 7, even small alterations of the cytoskeleton during malignant transformations can be detected from optical deformations. MOS experiments with tumor cell lines clearly show that malignant transformation causes cell softening for small deformations which correlates with an increased rate of proliferation compared to normal cells. Additionally, three clinical studies were carried out to prove the potential of the MOS for cancer diagnosis. First, primary oral squamous carcinoma cells from patients with early dysplasia and malignant tumors were probed with the MOS and compared with the deformability of primary oral cells from healthy donors. Second, breast tumor cells were resected from the women’s body and deformed within the MOS together with primary normal breast epithelial cells. Third, primary cervix carcinoma cells and normal epithelial cells resected from the same morphological compartment of the same women were examined. From all experiment we clearly found that tumor cells are softer compared to normal cells and exhibit a broader distribution of optical deformability. Since cell softening during malignant transformation seems to be a universal behavior of tumor cells, the MOS offers the possibility to detect many different types of tumors without any further knowledge of the molecular details of the cells. Thus, the MOS is a novel and highly promising tool for cancer diagnoses since highly expensive and specific molecular markers that only detect single alteration on the molecular level can be neglected.
4:30 PM - **JJ2.6
Implanted Diagnostic Devices.
Michael Cima 1 2
1 Department of Materials Science & Engineering, Massachusetts Inst. of Technology, Cambridge, Massachusetts, United States, 2 The David H. Koch Institute for Integrative Cancer Research, Massachusetts Inst. of Technology, Cambridge, Massachusetts, United States
Show AbstractImplantable magnetic resonance (MR) readable sensors afford the opportunity to detect various biomarkers in vivo and in real time. These measurements can be made through multiple layers of tissue and in a non-invasive manner. This talk focuses on two such sensors—the first a nanoparticle-based device for detecting cardiac biomarkers, and the second a sensor comprising of an MR-sensitive material for measuring tissue oxygenation.Nanoparticle-based sensors work on the principle that iron oxide nanoparticles clustered around analyte molecules can change the transverse relaxation time constant, T2, of surrounding water protons. Nanoparticles functionalized with antibodies can be made to detect proteins. These nanoparticles encapsulated in a discrete device behave as dosimeters, since antibody binding is essentially irreversible. These devices can be imaged on an MRI machine and the change in T2 inside the device will correspond to the total amount of analyte to which the device has been exposed. We fabricated small discrete sensors that use this mechanism to measure cardiac biomarkers and characterized their performance in vivo in a murine model of myocardial infarction.Measuring the concentration of dissolved oxygen in the tumor microenvironment is yet another example for which implanted diagnostic devices offer many potential advantages. The effective radiation dosage to a cancer patient depends on the level of tumor oxygenation—hypoxic tumors require a higher dose of radiation than non-hypoxic tumors for clinically similar outcomes. We developed a new class of dissolved oxygen sensors that are a composite of polydimethylsiloxane and an oxygen-responsive, MR-sensitive siloxane. The longitudinal relaxation time constant, T1, of the material changes with oxygen concentration and can be detected using magnetic resonance relaxometry. Compared to existing invasive techniques to measure tissue oxygenation, such as using needle electrodes, these sensors can be implanted during a biopsy procedure. The implanted sensors can be read non-invasively, and will monitor the same region of the tumor eliminating errors arising from repeatedly positioning a probe. The result is more consistent measurements and less invasive treatment for the patient.
5:00 PM - JJ2.7
Sensing Energy Metabolism In Vivo – Visualization of Lipolytic Enzyme Activity by Real-Time MRI Using Nanocrystals.
Oliver Bruns 1 2 , Alexander Bartelt 3 , Ulrich Tromsdorf 5 , Horst Weller 5 , Moungi Bawendi 1 , Rudolph Reimer 2 , Barbara Freund 3 , Peter Nielsen 3 , Joerg Heeren 3 , Harald Ittrich 4
1 Chemistry, MIT, Cambridge, Massachusetts, United States, 2 Microtechnology and Electron Microscopy, Heinrich-Pette-Institute, Hamburg, Hamburg, Germany, 3 Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, 5 Chemistry, University of Hamburg, Hamburg, Hamburg, Germany, 4 Diagnostic and Interventional Radiology Department and Clinic, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany
Show AbstractBesides glucose, lipids are the major fuel in the blood for energy consumption and tissue proliferation. Lipoprotein lipase (LPL) is the master regulator of vascular lipid metabolism. LPL mediates the release of fatty acids from triacylglycerol that are transported by lipoproteins in the blood. It acts thereby as a gatekeeper for fatty acid uptake comparable to the role glucose transporters for glucose uptake.Recently evidence accumulated that LPL activity is implicated in tumor biology as well. Reports found a link between high expression of LPL by non-small cell lung cancer tumor cells and a shorter patient survival. The same correlation of high LPL expression and poor clinical outcome was found in chronic lymphocytic leukemia. Taken together, these studies suggest an important role for LPL in tumor development as it delivers energy for tumor growth.Here, we present an in vivo sensor for LPL activity based on SPIO and QD nanocrystals.A recombinant lipoprotein model named nanosomes which carries different species of nanocrystals was recently established (Bruns et al. Nature Nanotechnology 2009, Bartelt et al. Nature Medicine 2011). Given the high flexibility and exceptional signal properties, nanosomes are the ideal platform for LPL sensing. Nanosomes allow to sense LPL activity in vivo by non-invasive real-time MRI imaging. In mouse models the upregulation of LPL activity could be detected by MRI and high-speed intravital confocal imaging. Inhibition and removal of LPL from tissue could be detected by in vivo imaging. These results were confirmed with quantitative measurements using radiolabelled nanocrystals.Sensing LPL activity by fluorescence microscopy and non-invasive MR imaging will allow measuring the biological importance of LPL function and dysfunction in target organs online in vivo. A sensor will thereby allow detecting changes in disease-associated LPL modulation for example during an anti-tumor therapy. Therefore, in future LPL activity in disease-affected tissues might be used to monitor effects of a therapeutic intervention from early on.References:Bartelt A, Bruns OT, Reimer R, Hohenberg H, Ittrich H, Peldschus K, Kaul MG, Tromsdorf UI, Weller H, Waurisch C, Eychmüller A, Gordts PLSM, Rinninger F, Bruegelmann K, Freund B, Nielsen P, Merkel M and Heeren J, Brown adipose tissue activity controls triglyceride clearance. Nature Medicine, 2011 Feb;17(2):200-5.Bruns OT, Ittrich H, Peldschus K, Kaul MG, Tromsdorf UI, Lauterwasser J, Nikolic MS, Mollwitz B, Merkel M, Bigall NC, Sapra S, Reimer R, Hohenberg H, Weller H, Eychmüller A, Adam G, Beisiegel U, Heeren J, Real-time magnetic resonance imaging and quantification of lipoprotein metabolism in vivo using nanocrystals. Nature Nanotechnology, 2009 Mar;4(3):193-201.
5:15 PM - JJ2.8
Development of Efficient Quantum Dot Antibody(QD-Ab) Conjugation to Label Single Cells In Vivo.
Hee-Sun Han 1 , Jayeeta Bhaumik 2 , Walid Kamoun 2 , Becky Chen 2 , Dan Duda 2 , Rakesh Jain 2 , Moungi Bawendi 2
1 Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States, 2 Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States
Show AbstractWe have developed an efficient method of conjugating antibodies to QDs using tetrazine norbornene cycloaddition. This conjugation results in small (~20nm HD), bright and stable QD conjugates. The small size of the conjugates promotes penetration of the QD conjugates through biologically crowded regions. High quantum yield QD conjugates with minimal non-specific binding allowed single cell labeling in vivo. The activity of antibodies conjugated to QD was tested using flow cytometry by double staining cells with QD-Ab and dye conjugated antibodies. The bio compatibility of QD-Ab conjugates was also verified with QD-IgG constructs. QD-IgG conjugates, which do not target cells, showed normal pharmaco-kinetic clearance without displaying non-specific interactions in vivo. In vivo imaging using QD conjugates is demonstrated in murine models for both multicellular structures such as vessels and for single hematopoietic stem cells in bone marrow by multiplexing with different QD-Ab markers. The methods implemented in this study open up the possibility to investigate individual cells in vivo for extended time periods.
5:30 PM - JJ2.9
Rapid, Label-Free, Electrical Whole Blood Bioassay Based on Nanobiosensor System.
Hsiao-Kang Chang 1 , Chongwu Zhou 1
1 Electrical Engineering, Univ. of Southern California, Los Angeles, California, United States
Show AbstractBiomarker detection based on nanowire biosensors has attracted a significant amount of research effort in recent years. However, only very limited research work has been directed toward biomarker detection directly from physiological fluids mainly because of challenges caused by the complexity of media. This limitation significantly reduces the practical impact generated by the aforementioned nanobiosensors. In this study, we demonstrate an In2O3 nanowire-based biosensing system that is capable of performing rapid, label-free, electrical detection of cancer biomarkers directly from human whole blood collected by a finger prick. Passivating the nanowire surface successfully blocked the signal induced by nonspecific binding when performing active measurement in whole blood. Passivated devices showed markedly smaller signals induced by nonspecific binding of proteins and other biomaterials in serum and higher sensitivity to target biomarkers than bare devices. The detection limit of passivated sensors for biomarkers in whole blood was similar to the detection limit for the same analyte in purified buffer solutions at the same ionic strength, suggesting minimal decrease in device performance in the complex media. We then demonstrated detection of multiple cancer biomarkers with high reliability at clinically meaningful concentrations from whole blood collected by a finger prick using this sensing system.
Symposium Organizers
Piotr Grodzinski National Cancer Institute
Scott Manalis Massachusetts Institute of Technology
Sonke Svenson Cerulean Pharma Inc.
Xing-Jie Liang National Center for Nanoscience and Technology of China
Wenbin Lin University of North Carolina-Chapel Hill
JJ5: Poster Session - Nanofunctional Materials, Nanostructures, and Nanodevices for Cancer Applications
Session Chairs
Piotr Grodzinski
Wenbin Lin
Tuesday PM, November 29, 2011
Exhibition Hall C (Hynes)
JJ3: Bio-Nano-Material for Cancer I
Session Chairs
Tuesday PM, November 29, 2011
Room 203 (Hynes)
9:30 AM - **JJ3.1
Quantum Dots Capable of Efficient Translocation through Nuclear Pore Complexes.
Jan Liphardt 1
1 Physics, UC Berkeley, Berkeley, California, United States
Show AbstractThe Nuclear Pore Complex (NPC) is the selective filter that facilitates all exchange between the cytoplasm and the nucleus in eukaryotic cells, allowing small molecules to passively diffuse through, while larger cargos require specific transport receptors to translocate. How NPCs achieve their exquisite selectivity remains unclear. We have developed a single molecule assay based on small (18 nm diameter) protein-functionalized Quantum Dots (QDs) for studying (with a mean spatial precision of 6 nm and a temporal resolution of 25 ms) the motion of single cargos as they approach, translocate, and exit the NPC. Optical tracking of single QD cargos reveals the individual steps involved in the import reaction. There is a size-selective cargo barrier in the cytoplasmic moiety of the central channel. The majority of QDs are rejected early rather than spending long times partitioned in the channel. Translocation is not governed by simple receptor-NPC binding interactions; rather, the central channel behaves in accordance with the ‘selective phase’ model. Finally, in the absence of Ran, cargos still explore the entire volume of the NPC, but have a dramatically reduced probability of exit into the nucleus, suggesting that NPC entry and exit steps are not equivalent and that the pore is functionally asymmetric to importing cargos. The overall selectivity of the NPC appears to arise from the cumulative action of a cascade of filters, only the last of which is irreversible.
10:00 AM - JJ3.2
New Route for the Synthesis of Multifunctional Gold Nanorods - Surgical Technology for Spectroscopy, Imaging and Therapy.
Clement Barriere 1 , Pilar Garcia-Allende 1 , Ji Qi 1 , Daniel Elson 1
1 Surgery and Cancer, Imperial College London, London United Kingdom
Show AbstractNanoparticles have undergone sustained study by scientists over the last decade as a potential new tool for cancer healthcare. One important possibility for these new materials is the possibility to produce controlled multifunctional constructs that may be used for different applications: imaging, diagnosis, drug delivery and therapy. In particular, gold nanorods (GNRs) are very promising as they are already multifunctional: the SPR (Surface Plasmon Resonance) signal, tuneable to 800 nm for a deeper tissue penetration can allow detection with diffuse reflectance spectroscopy (DRS). Previous work has also shown that they can be used as a powerful therapy agent.In this work, we described the controlled synthesis of a new polyfunctional nanorods and their application for DRS detection, fluorescence imaging and therapy. For the preparation of the GNRs, we used a synthesis described previously by Seo et al. To remove the toxic surfactant we replaced it by a polyethylene glycol (PEG) with a thiol and an amine as the terminal groups (SH-PEG-NH2). This PEG was prepared from the diamine PEG and was monothiolated with Traut‘s reagent. We then show that after functionalisation of the GNRs, the free amine group can be bound to any acid group to achieve the corresponding amide. In our case this can involve fluorescein for fluorescence, folic acid for targeting and Doxorubicin as a drug.The nanomaterials described have been tested both in vitro for cytotoxicity and ex-vivo for DRS to detect the SPR peak at 800 nm and fluorescence imaging using modified laparoscopic Instruments. Results show a limited toxicity except when doxorubicin is present on the GNRs or therapeutic light is applied. Our results suggest that GNRs should be of interest in medical applications, especially image guided endoscopic surgical intervention or as an adjuvant to current methods. In addition, the photothermal therapy experiments show an increase in temperature sufficient to invoke apoptosis or necrosis, depending on the energy dose given.
10:15 AM - JJ3.3
Selective Triggered Release from Gold Nanorods.
Kimberly Hamad-Schifferli 1
1 Biological and Mechanical Engineering, MIT, Cambridge, Massachusetts, United States
Show AbstractThe synergistic combination of nanotechnology and biology has resulted in numerous of innovative approaches for using biomolecules as machines, new therapies for diseases, and biological and biomolecular sensors. One of the most exciting prospects of nanotechnology is that nanoparticles can act as a handle by which one can control nanoscale processes, particularly biological ones. The use of gold nanoparticles has sparked great interest in cancer therapy for their abilities to be excited externally and trigger the release of payloads. This has potential for use as controlling the release of multiple therapeutic agents, which is challenging for passive release systems. We use laser excitation of gold nanorods to control the release of multiple species independently. Ultrafast laser excitation at the nanorod longitudinal surface plasmon resonance heats the nanorod to a high local temperature, inducing melting, which can release biomolecules conjugated to the nanorod. Because the SPR is tunable by changing nanorod aspect ratio, nanorods with different aspect ratios can be excited independently at different wavelengths. We exploit this property for selective and mutually exclusive release of two different payloads, demonstrating this for DNA oligonucleotides, showing that the released DNA retains function after release. Therapeutic applications for utilizing selective release from nanorods will be discussed.
10:30 AM - JJ3.4
Hydrodynamic Fractionation of Finite Size Gold Nanoparticle Clusters for Biomedical Applications.
De-Hao Tsai 1 , Tae Joon Cho 1 , Frank DelRio 1 , Julian Taurozzi 1 , Michael Zachariah 1 2 , Vincent Hackley 1
1 Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland, United States, 2 Departments of Mechanical Engineering and Chemistry, University of Maryland, College Park, Maryland, United States
Show AbstractWe demonstrate a high resolution in situ experimental method for performing simultaneous size-classification and characterization of functional gold nanoparticle clusters (GNCs) based on asymmetric-flow field flow fractionation (AFFF). Field emission scanning electron microscopy, atomic force microscopy, multi-angle light scattering (MALS), and in situ ultraviolet-visible optical spectroscopy provide complementary data and imagery confirming the cluster state (e.g., dimer, trimer, tetramer), packing structure, and purity of fractionated populations. An orthogonal analysis of GNC size distributions is obtained using electrospray-differential mobility analysis (ES-DMA). We find a linear correlation between the normalized MALS intensity (measured during AFFF elution) and the corresponding number concentration (measured by ES-DMA), establishing the capacity for AFFF to quantify the absolute number concentration of GNCs. The results and corresponding methodology summarized here provide the proof of concept for general applications involving the formation, isolation and in situ analysis of both functional and adventitious nanoparticle clusters of finite size.
10:45 AM - JJ3.5
Force Spectroscopy Mapping of the Mechanical Properties of Polyethylene Glycol Brushes on Gold Substrates.
Gheorghe Stan 1 , Frank DelRio 1 , Robert MacCuspie 1 , Robert Cook 1
1 Ceramics Division, National Institute of Standards and Technology, Gaithersburg, Maryland, United States
Show AbstractA necessary step in advancing the use of polyethylene glycol (PEG) surface coatings in critical biotechnological applications such as cancer treatments is to provide direct and reliable nanoscale property characterization. The access and measurements for such characterization are currently provided by scanning probe methods, which are capable of assessing heterogeneity of both surface coverage and properties with nanoscale spatial resolution. In particular, atomic force microscopy (AFM) can be used to detect and quantify the heterogeneity of surface coverage, whereas atomic force spectroscopy can be used to determine mechanical properties, thereby revealing possible heterogeneity of properties within coatings. In this work, AFM and force spectroscopy were used to characterize the morphology and mechanical properties, in compression and tension, of thiol-functionalized PEG surface coatings on flat gold substrates in aqueous solution and in air. Thiol-functionalized PEG offers a direct and simple method of attachment to gold substrates without intermediate anchoring layers, and therefore can be exploited in developing PEG-functionalized gold nanoparticles. AFM was used to investigate the morphology of the PEG coatings as a function of concentration and molecular weight; the commonly-observed coverage was in the form of sparse, brush-like islands. Force spectroscopy was utilized to study the mechanical properties of the PEG coatings in compression and tension as a function of molecular weight. A constitutive description of the mechanical properties of PEG brushes was achieved through a combinatorial analysis of the statistical responses acquired in both compression and tension tests. Such a statistical characterization provides a straightforward procedure to assess the nanoscale heterogeneity in the morphology and properties of PEG coverage.
11:30 AM - **JJ3.6
Nanomaterial Characterization: Methodologies for Successful Drug Development.
Anil Patri 1
1 , Nanotechnology Characterization Laboratory, SAIC-Frederick, Inc., Frederick, Maryland, United States
Show AbstractRecent advances in the utility of nanoscale materials designed for detection and drug delivery to cancer are furthering hope for better diagnostic and therapeutic options. As these promising nanotechnology based drugs and imaging agents are maturing towards clinical trials, challenges are arising in the definition of batch-to-batch consistency, scale up, and GMP manufacturing with well-defined QA/QC. The nuances in measuring and monitoring the composition, size polydispersity, surface characteristics, ligand heterogeneity, purity, stability and other relevant parameters in appropriate buffers and/or dry state are not well understood. Slight changes in these nanomaterial characteristics can have a profound impact on the safety and efficacy profiles of the drugs and imaging agents in vivo. Furthermore, multifunctional nanomaterials that contain targeting ligands, therapeutic payloads and imaging agents pose additional challenges in characterization and consistency in manufacturing. While many challenges still exist in the chemistry, manufacturing and controls (CMC), there are common parameters that need to be monitored for successful nanomaterial based drug development. This presentation will cover the characterization methodologies, parameters, and nuances often encountered in the preclinical development and analysis process. Preclinical characterization resources for the acceleration of promising nanotechnologies, available through the Nanotechnology Characterization Laboratory, will be presented.Funded by NCI Contract No. HHSN261200800001E.
12:00 PM - JJ3.7
Acid- and Urea-Functionalized Polycarbonate Micellar Nanoparticles Stabilized by Hydrogen-Bonding for Anticancer Drug Delivery.
Amalina Attia 1 , Jeremy Tan 1 , Chuan Yang 1 , James Hedrick 2 , Yi-Yan Yang 1
1 , Institute of Bioengineering and Nanotechnology, Singapore Singapore, 2 , IBM Almaden Research Center, San Jose, California, United States
Show AbstractPolymeric micellar nanoparticles are often used for the delivery of anticancer drugs due to their unique core/shell structure, ease of functionalization, prolonged circulation in the blood and targeting ability towards leaky tumor tissues. Kinetic stability and drug loading capacity are two major factors that should be considered in the design of polymeric micelles as carriers. We have recently reported novel mixed micelles formed via hydrogen-bonding from a block copolymer of poly(ethylene glycol) (PEG) and acid-functional polycarbonate, and another block copolymer of PEG and urea-functional polycarbonate, and showed that they provided high loading capacity for the anticancer drug doxorubicin containing an amine group, excellent kinetic stability and nanosize with narrow size distribution. To simplify polymer synthesis and fabrication process of mixed micelles, the present study is aimed to design block copolymers of PEG and polycarbonate bearing both urea- and acid-functional groups in the same backbone so that they can be used to form dual-functional micelles with high drug loading capacity and kinetic stability. The dual-functional block copolymers with well-controlled molecular weight were synthesized by metal-free organocatalytic ring-opening polymerization (ROP) of urea- and acid-functionalized cyclic carbonates using methoxy PEG as a macroinitiator. The number of urea and acid groups was varied to study their effects on the kinetic stability and drug loading capacity. With an optimized number of acid and urea groups, high drug loading level and nanosize were acquired. Distribution (random/block) of the urea and acid groups in the backbone also affected their self-assembly behavior and stability. When the placement of acid and urea groups are in block form, intra-molecular hydrogen-bonding between the urea and acid groups hindered the polymers from self-assembling into micelles through inter-molecular hydrogen-bonding, leading to a wide size distribution. However, the copolymers with acid- and urea-functional groups distributed randomly in the hydrophobic block yielded nanosized micelles with narrow distribution, high DOX loading level and enhanced kinetic stability when exposed to a destabilizing agent. About 35 wt% of DOX was loaded with the random copolymer through ionic interaction formed between the amine group in DOX and the acid group in the copolymer. DOX release from the micelles was prolonged without any initial burst release. The copolymer was non-cytotoxic against human embryonic kidney HEK293 and human carcinoma HepG2 cell lines. Primarily, killing efficiency of DOX-loaded micelles towards HepG2 cells was comparable to free DOX.
12:15 PM - JJ3.8
Iron Carbide Nanoparticles Elaboration: Composition, Size Control and Air Stability. Applications to Magnetic Hyperthermia.
Anca Meffre 1 , Boubker Mehdaoui 1 , Sebastien Lachaize 1 , Julian Carrey 1 , Pier Fazzini 1 , Marc Respaud 1 , Bruno Chaudret 1
1 , INSA toulouse, Toulouse France
Show AbstractUp to now, no wet chemical methods for the synthesis of colloidal iron carbide nanoparticles (NPs) were described despite their potential interest in nanotechnology. Indeed, their high magnetization, their robustness versus oxidation compared to iron (0) nanoparticles, the possibility to modulate the magnetic properties as a function of the carbon contain, make them interesting iron alternatives materials for biomedical applications, catalysis or electronic and spin–dependent tunnelling devices. Here we describe a new chemical route for the synthesis of iron carbide NPs with controlled sizes and compositions, and the first measure of their Magnetic Hyperthermia properties. The synthesis is based on the seeded growth methods. In a first step, a colloidal solution of iron (0) NPs stabilized by hexadecylammonium chloride and hexadecylamine is prepared according to Ref 1. Then, the Fe(CO)5 precursor is decomposed in various mild conditions. Under dihydrogen atmosphere, we were able to enlarge the particle size and activate the carbon diffusion inside the iron nanoparticle. The products are characterized by high resolution transmission electronic microscopy, Mössbauer spectroscopy and x-ray diffraction. Their mean size is well controlled by adjusting the seeds one and/or the Fe(CO)5 concentration. Depending on the annealing conditions of the product, we were able either to form pure Fe3C NPs or to recover an iron (0) core surrounded by a graphite layer. The air stability of these different materials studied thanks to SQuID measurements is reinforced compare to the pure iron (0) NPs ones. Hyperthermia measurements on these iron carbide NPs demonstrate an interesting potential.[2]1. A. Meffre, S. Lachaize, M. Respaud, C. Gatel, B. Chaudret, Journal of Material Chemistry, accepted 2. B. Mehdaoui, A. Meffre, L.M. Lacroix, S. Lachaize, M. Gougeon, M. Respaud, B. Chaudret, JMMM, 2010, 332, L49-L52; B. Mehdaoui, A. Meffre, L.M. Lacroix, S. Lachaize, M. Gougeon, M. Respaud, B. Chaudret, J.A.P., 2010, 107, 1
12:30 PM - JJ3.9
Impact of Gold Nanoparticle Size and Surface Chemistry on Diffusion in Poly(Ethylene Glycol) Hydrogels.
Stephanie Hume 1 , Kavita Jeerage 1
1 Materials Reliability Division, National Institute of Standards and Technology, Boulder, Colorado, United States
Show AbstractNanoparticles have emerged as a promising therapeutic and diagnostic tool, due to their unique physicochemical properties. The specific core and surface chemistries, as well as size and shape of nanoparticles, all play critical roles in transport of these materials through biological tissue. Tailoring of nanoparticles for specific biological functions can provide many advantages, as the particles can be selectively taken up by cells, and have been reported to cross the blood-brain barrier. Many biological therapies have focused on delivery of pharmaceuticals from hydrogel systems, and a similar approach is implemented here to further develop nanoparticle therapies. This research aims to develop a three-dimensional hydrogel system that serves as a platform for delivery of gold nanoparticles to surrounding tissues through diffusion out of the hydrogel. Within this system, nanoparticles are initially encapsulated, but either remain stationary or diffuse out of the gel based upon hydrogel composition. In contrast to many theoretical models, this study can provide insight into the specific diffusion of the gold particles of standard sizes, leading to accurate characterization for future therapies. In this work, PEG hydrogels were photopolymerized using concentrations of poly(ethylene glycol) dimethacrylate macromer between 5% - 30% by weight to obtain varied degrees of crosslinking. Swelling studies indicated that these crosslinking variations produced hydrogels with a range of mesh sizes between 8 nm - 140 nm. Gold particles of 10 nm, 30 nm and 60 nm were encapsulated within the hydrogels, and allowed to diffuse out. The gold nanoparticle diffusion from the gels was characterized as a function of mesh size through measurement of gold content in solution using ultraviolet-visible spectroscopy and atomic absorption spectroscopy. Interestingly, the gold nanoparticle movement was not consistent with the predicted diffusion based on the mesh size of the hydrogels and the hydrodynamic radius of individual gold nanoparticles. However, scanning electron microscopy of hydrogel cross-sections showed initial encapsulation of the dispersed nanoparticles, and time-dependent changes in particle density within the gel. In addition to size-based characterization of particle movement, the effect of surface functionalization on diffusion of the gold particles will be examined. Bioactive surface groups will be conjugated to the gold nanoparticles to examine whether aggregation or interaction with the macromer during polymerization inhibits diffusion throughout the hydrogel. Future studies involve co-encapsulating fibroblasts and gold nanoparticles within the hydrogels, and examining uptake of the particles and changes in cell metabolism or viability as a result of nanoparticle dosage over time.
12:45 PM - JJ3.10
Gold Nanoparticles with Tuning Near Infrared Absorption via Reaction of HAuCl4 and Na2S2O3 for Low Power Photothermal Cancer Therapy.
Guandong Zhang 1 , Jacek Jasinski 2 , Dhruvinkumar Patel 1 , Kurtis James 1 , Xinghua Sun 1 , Andre Gobin 1
1 Bioengineering Department, University of Louisville, Louisville, Kentucky, United States, 2 Conn Center for Renewable Energy Research, University of Louisville, Louisville, Kentucky, United States
Show AbstractGold nanoparticle (GNP) attracts great interests in chemistry, biomedicine, and electronics. Due to their unique optical properties, GNPs provide many advantages in the applications of photothermal therapy, immunoassay, drug delivery, imaging and detection, optical coatings and microdevices. The anisotropy in GNP shape offers high near infrared (NIR) absorption and improves the Raman scattering. Many gold nanostructures such as gold nanoshells, gold nanorods, gold triangular nanoprisms and gold nanocages have been developed and show the enhanced and adjustable absorption in the NIR regions, but most of their synthesis needs a complex multistep and time-consuming synthesis process.In this work, GNPs with precisely controlled NIR absorption are synthesized by a single step reaction of HAuCl4 and Na2S2O3, without assistant of additional templates, capping reagents or seeds for assembly. The GNPs are characterized by a UV-Vis-NIR spectrophotometer, zetasizer, and transmission electron microscope. The synthesized products consist of GNPs with different shape and size, including small spherical colloid gold particles (<5nm) and non-spherical gold crystals, which are mainly the truncated octahedron, pentagons and cuboctahedron, as well as the triangular shaped plate structures. Their NIR absorption results from the dipole surface plasmon resonance of the non-spherical gold crystals. The NIR absorption wavelengths and particle size increase with increasing of the molar ratio of HAuCl4 and Na2S2O3. These products can be further purified by centrifugation process to remove the spherical colloid gold particles, improving the NIR absorption. In-depth study reveals that the GNPs with good chemical and optical stability only form in a suitable range of the HAuCl4/Na2S2O3 molar ratio. When the molar ratio is above a critical value, the GNPs become unstable, due to Ostwald ripening. This can be understood as the result of the system free energy reduction. In the environment of large amount of Cl- and H+ ions, ionic Au–Cl complexes serve as transport species which allow the gold redeposit on some crystal surface, resulting in the particle decomposition and reassembly, as well as the quenching of NIR absorption. We demonstrate that these GNPs with well controlled NIR absorption have great potential for photothermal therapy of cancer cells. For cancer cell treatment, GNPs are prepared having NIR absorption to match the wavelength of the laser source. After surface modification, GNPs are attached to the cancer cells and actuated with low power laser. Under optimized conditions and with low dosage injection, GNPs show high efficiency to kill cancer cells, with little damage to normal cells. Tuning the optical absorption of the gold nanoparticles in the NIR regime via a robust and repeatable method will improve many applications requiring large quantity of NIR resonant nanoparticles.
JJ4: Nanotechnology-Enabled Drug Delivery and Therapy
Session Chairs
Tuesday PM, November 29, 2011
Room 203 (Hynes)
2:30 PM - **JJ4.1
Improving Delivery and Efficacy of Nano-Therapeutics by Normalizing Tumor Microenvironment.
Rakesh Jain 1
1 , Harvard Medical School - Massachusetts General Hospital, Boston, Massachusetts, United States
Show AbstractA solid tumor is like an aberrant organ – comprised of cancer cells and host cells embedded in an extracellular matrix – nourished by blood vessels and drained by lymphatic vessels. To unravel the complex physiology of this aberrant organ, our laboratory developed an array of imaging technologies as well as mathematical and animal models. Using these tools, we showed that blood and lymphatic vessels as well as matrix associated with tumors are abnormal and these abnormalities can create a hostile tumor microenvironment (e.g., hypoxia, high interstitial fluid pressure). We also revealed consequences of these abnormalities – specifically, how these abnormalities fuel malignant properties of a tumor as well as prevent treatments from reaching and attacking tumor cells. We then proposed a novel concept that “normalizing” tumor microenvironment - vessels and matrix - would allow cancer therapies to penetrate the mass and to function more effectively. We then showed first in mice and then in cancer patients that anti-angiogenic drugs - originally deigned to destroy tumor vessels - could, paradoxically, also “normalize” them, creating a window of opportunity to attack the cancer most effectively. More recently, we have shown that the drugs approved by the FDA for lowering hypertension can “normalize” the collagen matrix and improve the delivery and efficacy of nanomedicine. These concepts are also opening doors for treating other diseases, such as age-related wet macular degeneration, a leading cause of blindness, and neurofibromatosis-2, which can lead to deafness.1. R. K. Jain. Barriers to Drug Delivery in Solid Tumors. Scientific American, 271:58-65 (1994).2. R. K. Jain, Normalization of the Tumor Vasculature: An Emerging Concept in Anti-angiogenic Therapy of Cancer. Science, 307: 58-62 (2005). 3. R. K. Jain. Taming Vessels to Treat Cancer. Scientific American, 298: 56-63 (2008).4. R. K. Jain and T. Stylianopoulos. Delivering Nanomedicine to Solid Tumors. Nature Reviews Clinical Oncology 7:653-64 (2010). 5. B. Diop-Frimpong, V. P. Chauhan, S. Krane, Y. Boucher and R. K. Jain. Losartan Inhibits Collagen I Synthesis and Improves the Distribution and Efficacy of Nanotherapeutics in Tumors. PNAS 108:2909-14 (2011). 6. C. Wong, T. Stylianopoulos, J. Cuia, J. Martin, V. P. Chauhan, W. Jiang, Z. Popovic, R. K. Jain, M. G. Bawendi and D. Fukumura, “Multistage nanoparticle delivery system for deeppenetration into tumor tissue,” PNAS, 108: 2426-2431 (2011).7. V. P. Chauhan, T. Stylianopoulos, Y. Boucher and R. K. Jain, “Delivery of molecular and nanoscale medicine to tumors: Transport barriers and trategies,” The Annual Review of Chemical and Biomolecular Engineering 2:281–98 (2011).
3:00 PM - JJ4.2
Polymeric Backpacks for Cell-Mediated Drug Delivery.
Jonathan Gilbert 1 , Aaron Anselmo 3 , Albert Swiston 2 , Nishit Doshi 3 , Samir Mitragotri 3 , Robert Cohen 1 , Michael Rubner 2
1 Chemical Engineering, MIT, Cambridge, Massachusetts, United States, 3 Chemical Engineering, University of California Santa Barbara, Santa Barbara, California, United States, 2 Materials Science and Engineering, MIT, Cambridge, Massachusetts, United States
Show Abstract Polymeric backpacks for cells are anisotropic, stratified thin films that are hundreds of nanometers thick and microns wide. They are designed to attach strongly and specifically to the surfaces of many immune system cells and can contain a wide assortment of materials such as nanoparticles, proteins, DNA or binding ligands. Cellular backpacks are an example of a growing area of research on bio-hybrid materials which incorporate synthetic materials with biological systems. The potential applications of combining advanced synthetic materials with natural or altered functions of a cell include diagnostic applications, immune system engineering and drug delivery devices. In the present study we have begun testing the ability of cell backpacks to deliver drugs to local areas of inflammation in the body. Our first results show that these backpacks are phagocytosis resistant in vitro due to their unique flat shape and specific attachment mechanism. Unlike spherical drug delivery particles, which are internalized by macrophages, backpacks ride on the cell surface of highly phagocytic macrophages. This opens up a new route of cell-mediated therapy since the surface immobilization of particles on macrophages has never before been shown. Furthermore macrophages are known to travel to areas of inflammation in the body and thus may be used for highly directed drug delivery. We will also discuss work towards the attachment of backpacks to a variety of other immune cell types. The backpack can utilize a variety of cell attachment methods; however we focus on the use of hyaluronic acid to bind tightly to the cell surface CD44 receptor. This receptor is commonly found on immune system cells. Since the backpack leaves most of the cell surface unaltered, the cell can still interact with the environment and we have not seen any deleterious effects on the cell. We will also report on the controlled release of proteins, DNA or small molecules to the surrounding environment or the attached cell.
3:15 PM - JJ4.3
Targeted Delivery of Multicomponent Cargos to Cancer via Nanoporous Particle-Supported Lipid Bilayers.
Carlee Ashley 1 , Eric Carnes 2 , David Padilla 2 , Katharine Epler 2 , Robert Castillo 2 , Cheryl Willman 3 5 , Bryce Chackerian 4 5 , David Peabody 4 5 , Walker Wharton 3 5 , Jeffrey Brinker 2 5 6
1 Biotechnology and Bioengineering, Sandia National Labs, Livermore, California, United States, 2 Chemical Engineering, University of New Mexico, Albuquerque, New Mexico, United States, 3 Pathology, University of New Mexico, Albuquerque, New Mexico, United States, 5 Cancer Center, University of New Mexico, Albuquerque, New Mexico, United States, 4 Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, New Mexico, United States, 6 Self-Assembled Materials, Sandia National Labs, Albuquerque, New Mexico, United States
Show AbstractEncapsulation of drugs within nanocarriers that selectively target malignant cells promises to mitigate side effects of conventional chemotherapy and to enable delivery of the unique drug combinations needed for personalized medicine. To realize this potential, however, targeted nanocarriers must simultaneously overcome multiple challenges, including specificity, stability, and a high capacity for disparate cargos. To this end, we have developed porous nanoparticle-supported lipid bilayers (protocells) that synergistically combine properties of liposomes and nanoporous particles. Protocells are formed via fusion of liposomes to a spherical, high-surface-area, nanoporous silica core, followed by modification of the resulting supported lipid bilayer (SLB) with multiple copies of a targeting peptide, a fusogenic peptide, and PEG. Due to its high surface area (> 1000 m2/g), the nanoporous silica core possesses a higher capacity for therapeutic and diagnostic agents than similarly-sized liposomes. Furthermore, due to substrate-membrane adhesion energy, the core suppresses large-scale bilayer fluctuations, resulting in greater stability than unsupported liposomal bilayers. Interestingly, the nanoporous support also results in enhanced lateral bilayer fluidity compared to that of either liposomes or SLBs formed on non-porous particles; fluid SLBs enable recruitment of targeting ligands to the cancer cell surface, which dramatically enhances specific affinity. This combination of materials and biophysical properties enables high delivery efficiency and enhanced targeting specificity with a minimal number of targeting ligands, features that are crucial to maximize specific binding, minimize non-specific binding, reduce dosage, and mitigate immunogenicity.Using a targeting peptide that binds to human hepatocellular carcinoma (HCC), we have found that protocells exhibit a 10,000-fold greater affinity for HCC than for hepatocytes, endothelial cells, and immune cells, even at low peptide densities (~6-12 peptides/particle). We have, furthermore, loaded protocells with combinations of therapeutic (drugs, siRNA, toxins, and plasmids that encode shRNA) and diagnostic (quantum dots and iron oxide nanoparticles) agents, modified them to promote endosomal escape and nuclear accumulation of selected cargos (e.g. plasmids), and characterized their selective cytotoxicity to HCC. The enormous capacity of the high-surface-area nanoporous core (1000-fold greater than similarly-sized liposomes) combined with the enhanced targeting efficacy enabled by the fluid SLB (sub-nanomolar affinities at densities of ~6 peptides/particle), allow a single protocell loaded with a drug cocktail to kill a drug-resistant HCC cell, representing a 106-fold improvement over comparable liposomes. An article describing these results was featured on the May 2011 cover of Nature Materials.
3:30 PM - JJ4.4
Ultrastable, Redispersible, and Small Organically Modified Mesoporous Silica Nanoparticles as Carriers for Anticancer Drug Delivery.
Yu-Shen Lin 1 , Christy Haynes 1
1 Chemistry, University of Minnesota, Minneapolis, Minnesota, United States
Show AbstractMesoporous silica (MS) nanoparticles (NPs) are attracting much attention of late due to their unique characteristics, including well-sized control, large internal surface area and easy surface modification, making them promising candidates for biomedical applications. However, the low particle stability, nonspecific biomolecule adsorption, and unintentional degradation of these porous silica NPs in biological media result in rapid unintentional uptake by the immune system and limit their potential for in vivo biological use.Recently, we have shown that MS NPs have lower hemolytic activity and cytotoxic effect compared to their nonporous counterparts.[1,2,3] Additionally, we found that small MS NPs (<50 nm) with polyethylene glycol (PEG) modification and hydrothermal treatment are shown to exhibit higher particle stability in biological media at 37 oC compared to bare MS NPs and PEGylated MS NPs without hydrothermal treatment. These hydrothermally treated PEGylated particles are highly biocompatiable, resistant to degradation and nonspecific protein adsorption, and less efficiently taken up by macrophages.[4] Herein, we incorporate a secondary hydrophobic silane (chlorotrimethyl silane or 3,3,3-trifluoropropylchlorodimethyl silane) into PEGylated MS NPs to further increase the long-term particle stability in simulated body fluid, compared to hydrothermally treated PEGylated MS NPs. In addition, these co-modified MS NPs can be simply dried and redispersed to biological media and still maintain their long-term particle stability in physiological conditions. To demonstrate the versatility of this co-modified method, we further demonstrate the redispersity of ultrasmall (<30 nm), fluorescent and magnetic co-modified MS NPs. In addition, three different anticancer drugs (doxorubicin, paclitaxel, and docetaxel) are used to study the redispersity, loading capacity and delivery kinetics of the co-modified MS NPs. Finally, these redispersible drug-loaded MS NPs show dose-dependent cytotoxic effect to cancerous cells (HeLa) and exhibit higher cytotoxicity than free hydrophobic anticancer drugs.[5] References:[1]. Lin, Y.-S.; Haynes, C. L. Chem. Mater. 2009, 21, 3979-3986.[2]. Lin, Y.-S.; Haynes, C. L. J. Am. Chem. Soc. 2010, 132, 4834-4842.[3]. Mauer-Jones, M. A.; Lin, Y.-S.; Haynes, C. L. ACS Nano 2010, 4, 3363-3373.[4]. Lin, Y.-S.; Abadeer, N.; Haynes, C. L. Chem.Commun. 2011, 47, 532-534.[5]. Lin, Y.-S.; Abadeer, N.; Stevens, K. Haynes, C. L. 2011, in preparation.
3:45 PM - JJ4.5
Precise Manipulation of Gold Nanowires as Delivery Vehicles for Cancer Therapeutics.
Ike Chi 1 , Danru Qu 2 , XingYu Liu 1 , Chia-Ling Chien 2 , Hai-Quan Mao 1 3 , Robert Cammarata 1
1 Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland, United States, 2 Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland, United States, 3 Whitaker Biomedical Engineering Institute, Johns Hopkins University, Baltimore, Maryland, United States
Show AbstractElemental gold (Au) nanowires have attracted significant attention as basic research platforms and potential targeted delivery vehicles in biological studies because of their stability, low toxicity, and tunable properties [1]. In the current study, we aim to establish a platform that utilizes Au nanowires to mimic cytotoxic T cells in order to introduce the apoptosis of tumor cells. In particular, Au nanowire surfaces can be functionalized through surface modifications to the Ras ligands which can initiate apoptotic pathways once bound with Ras receptors on tumor cells. Here we fabricate monodispersed Au nanowires with large aspect ratios using template guided electrodeposition. We have previously shown that these Au nanowires can be precisely aligned and transported in suspension using a combination of torque in an alternating current electric field and Lorentz forces in a constant electric field [2-4]. As a result, functionalized nanowires can be directed to individual cells to trigger biochemical reactions or deliver drugs without affecting other neighboring cells [3-4]. Nanowire motion control is even precise enough to target specific regions of interest within an individual cell. As one challenge existed in cancer immunology is the precise manipulation of both cell to cell contact and the Ras ligand density in order to trigger apoptosis. This novel subcellular manipulation technique can serve as in vitro tool to comprehend our understanding in T-cell induced cancer toxicity. When combined with cancer target approaches, this system may be further utilized for targeted drug delivery for cancer therapeutics applications. References: [1] Chiung-Wen Kuo and Peilin Chen, Electrodeposited Nanowires and Their Applications, Book edited by: Nicoleta Lupu, ISBN 978-953-7619-88-6, pp.228, February 2010, INTECH, Croatia. [2] D. L. Fan, R. C. Cammarata, and C. L. Chen, Appl. Phys. Lett. 92, 093115 (2008). [3] D. L. Fan et al., Nature Nanotech. 5, 545-551 (2010). [4] Andrew J. Hilmer and Michael S. Strano, Nature Nanotechnology 5, 481-482, (2010).
4:30 PM - **JJ4.6
Design of Polymeric Nanoparticles to Improve Distribution Volume to Treat Brain Tumors.
W. Mark Saltzman 1 , Jiangbing Zhou 1 2 , Toral Patel 2 , Joseph Piepmeier 2
1 Department of Biomedical Engineering, Yale University, New Haven, Connecticut, United States, 2 Department of Neurosurgery, Yale University, New Haven, Connecticut, United States
Show AbstractTreatment of brain tumors is severely limited by the inability of systemically-delivery agents to cross the blood-brain barrier. Convection-enhanced delivery is a promising technique for local delivery of agents in the brain, but it could be improved by use of delivery vehicles that provide controlled release. Here, we present a novel method for fabricating polymer nanoparticles that are less than 100 nm in diameter, can be loaded with drugs and/or oligonucleotides, and are optimized for convective delivery to the brain. Additionally, we demonstrate the in vivo effectiveness of this system in an animal model of a human brain tumor. This delivery system can be readily translated into clinical practice.
5:00 PM - JJ4.7
Targeting Acidic Tumors with pH Responsive Luminescent Gold Nanoparticles.
Jie Zheng 1
1 , University of Texas at Dallas, Richardson, Texas, United States
Show AbstractNanoparticles allow the combination of a variety of molecular imaging modalities and local treatment of lesions, potentially catalyzing the shift of our current medical paradigm to “earlier detection and prevention”. In particular, gold nanoparticles with broad material properties hold great promise in cancer detection and therapy. However, very few gold nanoparticles can target acidic tumor microenvironment. In this talk, we will present a class of luminescent gold nanoparticles, which exhibit strong triplet-state emissions (J. Phys. Chem. C, 2010;7727) and can avidly bind to cancer cell membrane under mild acidic conditions (6.5 –5.3) even in the presence of serum proteins while no interactions were observed with tumor cells at pH 7.4 (J Amer. Chem. Soc, 2011, accepted). After introduced into the mice bearing with acidic tumors, the pH responsive luminescent gold nanoparticles showed a 75% tumor uptake elevation in an acidic cancer mouse model than their pH insensitive counterparts. More importantly, the luminescent gold nanoparticles have little accumulation in the liver and spleen, and they can be cleared from the body through kidneys with an efficiency of 10~100 times better than the same sized AuNPs (Angew. Chem. Int. Ed., 2011,3168).
5:15 PM - JJ4.8
Dexamethasone-Releasing Nanoparticles Assembled from Amphiphilic Block Copolyesters Bearing Pendant Cyclic Ketals.
Xinqiao Jia 1
1 Materials Science and Engineering, University of Delaware, Newark, Delaware, United States
Show AbstractPolyester-based amphiphilic block copolymers were synthesized by ring-opening copolymerization of ε-caprolactone (ε-CL) and 1,4,8-trioxaspiro-[4,6]-9-undecanone (TSU) using methoxy poly(ethylene glycol) mPEG as the initiator and Sn(Oct)2 as the catalyst. The resulting copolymers are abbreviated as ECTx, with x being the amount (in grams) of TSU added to the reaction mixture. Copolymers with TSU content in the hydrophobic block varying from 0, 14, 39 to 100 mol%, corresponding to ECT0, ECT2, ECT5, and ECT10, were synthesized by varying the monomer feed ratio. The random incorporation of TSU effectively disrupted the regularity of PCL molecular structure, hindering its ability to crystallize. Dexamethasone (Dex)-loaded, ECT2 nanoparticles with an average diameter of 70-107 nm were prepared by a precipitation and solvent exchange process. Wide angle X-ray diffraction analysis showed an efficient entrapment of Dex within the hydrophobic interior of ECT2 nanoparticles. In vitro Dex release was carried out under infinite sink conditions in phosphate buffered saline at pH 7.4. A biphasic release profile, with an initial release at a rate of 30% per day for 2 days followed by a sustained release at a moderate rate of 5% per day for 7 days, was observed. The blank ECT2 nanoparticles are non-toxic to non-adherent leukemic cells, while the Dex-encapsulated nanoparticles induced a dose-dependent apoptosis. ECT2 nanoparticles were endocytosed and localized to the recycling endosome in cultured carcinoma cells. The apoptosis induced by the encapsulated dex, combined with the biocompatibility of the nanocarrier, promise to deliver effective treatment with reduced side effects to cancer patients.
5:30 PM - JJ4.9
Functional Nanoparticles for the Manipulation of Angiogenesis: Towards a New Method for Cancer Treatment.
Antonios Kanaras 1 , Dorota Bartczak 1 , Otto Muskens 1 , Tim Sanchez-Elsner 2 , Timothy Millar 2
1 School of Physics and Astronomy, University of Southampton, Southampton United Kingdom, 2 School of Medicine, University of Southampton, Southampton United Kingdom
Show AbstractManipulating the interactions of biological cells using nanotechnology is of great importance for the development of new diagnostic and therapy methods, drug delivery, and imaging. An important step to manipulate biological processes is to understand how the engineering, in terms of size, shape and functionality, of advanced colloidal nanoparticles can be employed to our benefit in order to control cellular functions. In this presentation we demonstrate a new approach to manipulate cell operations, which is based on the membrane-receptor specific interactions between colloidal peptide-capped gold nanoparticles and human umbilical vein endothelial cells [1]. Colloidal gold nanoparticles of similar charge and size but capped with different sequences of peptides can deliberately trigger specific cellular functions, which are strongly related to angiogenesis, one of the major process for tumor growth and metastasis. Laser treatment of endothelial cells, tagged by advanced nanoparticles, can lead to the deliberate control of cell mortality [2]. Different types of colloids such as hollow gold, gold nanorods and silica-gold core-shell are employed as a toolbox for the laser treatment, in order to further tune the functions of the survived cells. The cytotoxicity and cellular uptake of the different types of nanoparticles is assessed and discussed.References:[1]. Bartczak D.; Sanchez-Elsner T.; Louafi F., Millar T.; Kanaras* A. G.Small, 2011, 7, (3), 388–394.[2]. Bartczak, D.; Muskens, O. L.;Millar T.;Sanchez-Elsner T.;Kanaras* A. G.NanoLett, 2011, 11 (3), 1358–1363.
5:45 PM - JJ4.10
Biosynthesis and Adhesion of Gold Nanoparticles for Breast Cancer Detection and Treatment.
Emily Hampp 1 2 , Richard Botah 3 , Shola Odusanya 4 , Nicolas Anuku 5 , Karen Malatesta 1 , Winston Soboyejo 1 2
1 Mechanical & Aerospace Engineering, Princeton University, Princeton, New Jersey, United States, 2 Princeton Institute for Science and Technology of Materials (PRISM), Princeton University, Princeton, New Jersey, United States, 3 Department of Materials Science and Engineering, African University of Science and Technology, Abuja Nigeria, 4 Biotechnology Advanced Laboratory, Sheda Science and Technology Complex, Abuja Nigeria, 5 Chemistry and Chemical Technology, Bronx Community College, New York, New York, United States
Show AbstractGold nanoparticles (AuNPs) were successfully biosynthesized using B. megaterium, a common soil bacterium. Transmission electron microscopy (TEM) images show well-developed nanoparticles that are spherical and homogenous from reacting aqueous chloroaurate ions with bacterial medium conditioned by B. megaterium at pH 4. The AuNPs were synthesized by the bacterium extracellularly. Atomic force microscopy (AFM) measurements showed that the adhesion forces between the biosynthesized AuNPs and breast cancer cells were almost six times greater than the adhesion forces between the AuNPs and normal breast cancer cells. Furthermore, the adhesion forces of the biosynthesized AuNPs to breast cancer cells were three times greater than the adhesion forces between chemically synthesized particles and the same breast cancer cells. Finally, the adhesion forces between biosynthesized AuNPs conjugated to breast specific antibodies (AuNP conjugates) and breast cancer cells were almost five times greater than the adhesion forces between unconjugated AuNPs and breast cancer cells. The implications of the results are discussed for the development of nanostructures for the targeted detection and treatment of breast cancer.
JJ5: Poster Session - Nanofunctional Materials, Nanostructures, and Nanodevices for Cancer Applications
Session Chairs
Piotr Grodzinski
Wenbin Lin
Wednesday AM, November 30, 2011
Exhibition Hall C (Hynes)
9:00 PM - JJ5.10
Selective Triggered Release from Gold Nanorods.
Helena de Puig 1 4 , Salmaan Baxamusa 2 , Stefania Federici 5 , Helen D'Couto 2 , Dorma Flemister 2 , Mercedes Balcells 3 4 , Paolo Bergese 5 , Kimberly Hamad-Schifferli 1 2
1 Mechanical Engineering, MIT, Cambridge, Massachusetts, United States, 4 Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona Spain, 2 Biological Engineering, MIT, Cambridge, Massachusetts, United States, 5 Chemistry for Technologies Laboratory and INSTM, University of Brescia, Brescia Italy, 3 Health Sciences and Technology, MIT, Cambridge, Massachusetts, United States
Show AbstractGold nanorods (NRs) are attractive for biological applications, in particular, externally controlled release of biomolecules, which has been demonstrated by laser irradiation of the nanorod (NR) at the longitudinal surface plasmon resonance peak (SPR). The SPR is tunable by changing the NR aspect ratio; therefore, NRs with different aspect ratios can be independently excited at different irradiation wavelengths, to release different payloads. We are using this approach to create a biological switch for blood clotting by releasing a ssDNA aptamer, thrombin binding aptamer (TBA) upon laser irradiation. Blood clotting can be controlled by releasing TBA that binds and inhibits thrombin and an antidote that restores its activity. The aptamers and the antidotes are loaded onto NRs with different aspect ratios. This enables us to use laser excitation at one wavelength to deliver the aptamer and trigger the inhibition of thrombin, and then use a different wavelength to deliver the antidote and reverse the effects of the aptamer. Because surface and interface effects dominate at the nanoscale, we also quantify the interfacial interactions between the aptamer, thrombin and the antidote, all of which affect the release of the species. This localized, selective and externally controlled release of biomolecules represents an advance in a number of biological applications, where the current practice is systemically administering drugs though the whole bloodstream and relying on physiological clearance to restore the system’s activity.
9:00 PM - JJ5.12
Functionalized Platinum Nanoparticles as an Active Targeting Drug for Cancer in Zebrafish.
Yiwei Teow 1 2 , Zhiyuan Gong 2 3 , Suresh Valiyaveettil 1 2
1 Chemistry, National University of Singapore, Singapore Singapore, 2 , NUS Graduate School for Integrative Sciences and Engineering (NGS), Singapore Singapore, 3 Biological Sciences, National University of Singapore, Singapore Singapore
Show AbstractIn the conventional drug development process, the most commonly encountered concerns are solubility, bioavailability and targeting. Poor solubility and bioavailability often lead to higher concentrations of the drug to be used. Without proper targeting, widespread toxicity in different parts of the body is observed, especially toward fast growing cells. These adverse effects include nausea, vomiting and hair loss, to name a few. A clever design and engineering using nanotechnology concepts offers excellent materials for packaging toxic drugs, delivering them right to the target (tumor) and release upon a signal (presence of enzymes, pH changes, or reducing/oxidizing environment). Nanomaterials were found to distribute and translocate to different parts of the body and when synthesized at the correct size range, circulation can be improved and taken up by tumors via the enhanced permeability and retention effect (EPR).1 We have previously shown that folic acid can be tagged to platinum nanoparticles and used for targeting cancer cells (HeLa and MCF7) which overexpress folate receptors on their cell surface with toxic effects at µg/ml levels.2 We moved on to an in vivo model to investigate the anticancer activities of platinum nanoparticles. The synthesis of nanoparticles and results from in vivo studies using zebrafish as a model will be discussed. Full data will be given to show the efficacy of our design strategies towards developing nanoparticles-based drug candidates.
9:00 PM - JJ5.14
Measuring the Efficacy of Ligand Displacement on Functionalized Gold Nanaoparticles Using Complementary Characterizations - Applications in Cancer Therapeutics.
De-Hao Tsai 1 , Melanie Shelton 1 , Frank DelRio 1 , Suvajyoti Guha 1 2 , Michael Zachariah 1 2 , Vincent Hackley 1
1 Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland, United States, 2 Departments of Mechanical Engineering and Chemistry, University of Maryland, College Park, Maryland, United States
Show AbstractThe “separate-and-analyze” approach (i.e., removing surface-bound functional ligands from nanoparticles and solubilizing them prior to analysis) is widely used for characterizing molecular conjugation. Ligand displacement is typically employed for the separation step, but the uncertainty of recovery efficiency (i.e., the fraction of released versus residual ligands) can be a significant concern, possibly limiting the capacity for quantification of results.In this study we apply a toolbox characterization approach to better understand the efficiency of the ligand displacement process. Characterization methods include dynamic light scattering, electrospray-differential mobility analysis, fluorescence assay, and attenuated total reflectance-Fourier transform infrared spectroscopy. Thiolated polyethylene glycol (SH-PEG) and bovine serum albumin (BSA) conjugated to gold nanoparticles (AuNPs) are chosen as our model system because of the relevance to cancer therapeutics. Because of their small size (avoiding steric hindrance effects) dithiothreitol (DTT) and mercaptopropionic acid (MPA) are used for displacement of ligands. Combining information related to changes in physical dimensions and spectroscopic signals, we quantify adsorption of DTT and MPA, desorption of SH-PEG and BSA, and then draw conclusions regarding efficacy of the ligand displacement process. The complementary characterization methods demonstrated here can be used as a prototype approach to quantitatively study the removal efficiency of other types of conjugated ligands, such as other proteins or deoxyribonucleic acid.
9:00 PM - JJ5.15
Surface Modification of Titanium Dioxide to Enhance Biocompatibility and Selectivity for Use in Photodynamic Cancer Therapy.
Isabella Schmitt 1 , Matthew Tarr 1
1 Department of Chemistry and Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana, United States
Show AbstractNanomaterial semiconductors, such as titanium dioxide, exhibit photocatalytic activity useful for various applications. Photodynamic therapy is one area in which nanomaterials can be used for cancer treatment. However, these inorganic nanomaterials must first be made biocompatible by adding appropriate molecules to the surface of the particles. In this study, titanium dioxide was made biocompatible by coating the surface with organic molecules containing polar or ionic functional groups. These organic molecules were attached to the surface of the TiO2 nanoparticles using silylation. Multiple functional groups were added to each particle in order to obtain several desired properties; each property results from a single type of functional group. In order to form covalent Ti-O-Si linkages, nanoparticles were treated with organic methoxysilanes. The functional groups of these molecules were chosen to prevent aggregation, impart biocompatibility, and provide a reactive site for attachment of other molecules such as streptavidin. The streptavidin was further utilized for strong binding of a biotinylated, fluorescently tagged antibody, which could then be used for targeted binding of a desired antigen. The flourophore allowed an easy method for detection of the labeled particles using fluorescence microscopy. FTIR spectroscopy was used to verify that the silane and its functional group were covalently attached to the oxide surface. Transmission electron microscopy (TEM) allowed assessment of how surface modifications affected particle aggregation. Energy dispersive spectroscopy associated with the TEM verified that the modified nanoparticles contained Si, S, and N (all were elements of the added functional groups). The antibody labeled TiO2 particles could then be used in a sandwich assay to verify that the particles would selectively bind to the antigen. Once this binding is verified, selective phototreatment of the antigen can be carried out.
9:00 PM - JJ5.16
Human Serum Albumin Nanoparticles Loaded with Magnetic Nanoparticles and Organic Molecules for Use in Cancer Treatment.
Isabella Schmitt 1 , Kristen Schexnayder 1 , David Bwambok 1 , Arden Wells 2 , Leszek Malkinski 2 , Matthew Tarr 1
1 Department of Chemistry and Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana, United States, 2 Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana, United States
Show AbstractMagnetic nanoparticles (MNP) can be used for hyperthermic treatment of cancer. This ability is due to the particles aligning their magnetic moments with an applied AC magnetic field. Conversion of the applied magnetic field results in local heating that can kill cancer cells. However, the nanoparticles must first be localized in a tumor in order for magnetic hyperthermic treatment to be effective. Biocompatibilty is essential in delivery of particles to the tumor. Encapsulation of MNP in human serum albumin (HSA) nanoparticles provides a biocompatible delivery platform that can be surface modified for selectivity. Furthermore, the HSA nanoparticles can be loaded with chemotherapy agents to create a multimodal treatment approach. In this study, a range of magnetic iron oxide nanoparticles (10-30 nm) were embedded into HSA nanoparticles (~100 nm). Transmission electron microscopy images showed a relatively uniform distribution of the MNPs in the HSA particles. Fluorescent molecules were also incorporated into the HSA nanoparticles to serve as surrogate drug molecules. Heating of the composite particles due to an applied AC magnetic field was monitored over a range of applied field strengths, frequencies, and exposure times. In addition, release of the fluorophore was monitored in order to understand kinetics of drug release. A linear correlation was observed between flourophore release and time of exposure to the AC magnetic field. The rate of flourophore release was also dependent on applied field strength, although this relationship was non-linear. Additional characterization tools included scanning electron microscopy and dynamic light scattering. These tools allowed observation of changes in particle size and shape as a function of exposure to the field. Parallel studies using enzymatic degradation of the HSA also showed release of the fluorophore. The HSA platform used in this study is advantageous because: 1) the platform allows simultaneous delivery of both an anti-cancer drug and hyperthermia, 2) the HSA is biocompatible and can be made selective through derivatization with antibodies, 3) release of the drug can be triggered by magnetic or enzymatic means, and 4) the MNPs can serve as contrast agents for MRI or X-ray techniques.
9:00 PM - JJ5.17
Synthesis of Gold Nanoparticles Coated with pH-Responsive Polymers and Evaluation of the Cellular Uptake.
Takeo Ito 1 , Eriko Kusaka 1 , Yu Isobe 1 , Sei-ichi Nishimoto 1
1 , Kyoto University, Kyoto Japan
Show AbstractGold nanorods (AuNRs) show surface plasmon absorption bands in the near-infrared region. This characteristic property may stimulate utilization of gold nanorods as novel nano-probes for non-invasive bioimaging such as photo-acoustic tomography. We synthesized herein a series of gold nanorods coated with pH-responsive polymers so as to investigate the effects of surface structure and zeta potential of nanoparticles on the cellular uptake via the surface charge-mediated endocytic pathway. The surface of gold nanorods was modified with polyethylene glycol (PEG@AuNR) and any of alkylamine derivatives, specifically diethylaminoethyl ester (1@AuNRs) and its amide analogs (2@AuNRs, 3@AuNRs). The surface-coated nanorods 1@AuNRs were pH-sensitive and the surface was positively charged at lower pH’s. In contrast, the alkylamino groups of 1@AuNRs were deprotonated into electrostatically neutral state at higher pH’s. The pH-sensitive gold nanorods were incubated with A549 cells (human lung cancer cells) to quantify the amount of their cellular uptake by inductively coupled plasma mass spectrometry. The result indicates that 1@AuNRs can be taken quickly into cells and thereafter slowly flow out of cells. Interestingly, only small portions of amide analogs (2@AuNRs, 3@AuNRs) were taken into cells, suggesting even minor structural changes affect their affinities toward the cell surface. The current study demonstrates potential application of the pH-sensitive nanorods to a probe for bioimaging of the acidic environment of tumor cells.
9:00 PM - JJ5.18
Zwitterionic-Coated Tantalum Oxide: New Nanoparticle Contrast Agents for X-Ray/CT Medical Imaging.
Matthew Butts 1 , Peter Bonitatibus 1 , Robert Colborn 1 , Todd Luttrell 1 , David Gascoyne 1 , Andrew Torres 1 , Brian Lee 1 , Paul Fitzgerald 1 , Michael Marino 1
1 Molecular Diagnostics Platform, GE Global Research, Niskayuna, New York, United States
Show AbstractClinically approved contrast agents for x-ray and CT diagnostic imaging are molecular compounds containing iodide. In efforts to achieve improved imaging efficacy, there has recently been interest in developing new agents based on coated nanoparticles containing elements such as tantalum which have high x-ray attenuation.1,2 Particles coated with shells containing zwitterionic functionality are particularly interesting due to the proposed protein resistance and general biocompatibility of this class of materials.3-7 Here we will describe the multi-gram synthesis of tantalum oxide nanoparticles protected with zwitterionic shells through the one pot in-situ coating of these particles with functionalized alkoxy silanes. The synthesis and characterization of two types of shells will be described in detail. “Single ligand” zwitterionic shells are those comprised of sulfobetaine or similar groups while “dual ligand” shells derive their zwitterionic character from the joint deposition of separate anionic and cationic functional groups. Particle properties including coating structure as determined by NMR spectroscopy, particle size and material purity will be presented. Particle solution properties such as viscosity and osmolality, important in consideration of in vivo applications, will also be described. Finally, pre-clinical CT imaging results in rats comparing the zwitterionic particles to one of today’s iodide agents will be presented.References1.Bonitatibus, P. J., Jr.; Torres, A. S.; Goddard, G. D.; Fitzgerald, P. F.; Kulkarni, A. M. Chem. Commun. 2010, 46, 8956.2.Oh, M. H.; Lee, N.; Kim, H.; Park, S. P.; Piao, Y.; Lee, J.; Jun, S. W.; Moon, W. K.; Choi, S. H.; Hyeon, T. J. Am. Chem. Soc. 2011, 133, 5508.3.Butts, M. D.; Colborn, R. E.; Bonitatibus, P. J., Jr.; Kulkarni, A. M.; Hay, B. A.; Torres, A. S.; Bales, B. C.; Marino, M. E. US Patent Application 2010/0166664, 2010, General Electric Company.4.Bonitatibus, P. J., Jr.; Butts, M. D.; Colborn, R. E.; Kulkarni, A. M.; Hay, B. A.; Torres, A. S.; Bales, B. C.; Marino, M. E. US Patent Application 2010/0278734, 2010, General Electric Company.5.Choi, H. S.; Liu, W.; Misra, P.; Tanaka, E.; Zimmer, J. P.; Ipe, B. I.; Bawendi, M. G.; Frangioni, J. V. Nat. Biotech. 2007, 25, 1165.6.Rouhana, L. L.; Jaber, J. A.; Schlenoff, J. B. Langmuir 2007, 23, 12799.7.Chen, S.; Zheng, J.; Li, L.; Jiang, S. J. Am. Chem. Soc. 2005, 127, 14473.
9:00 PM - JJ5.19
Polyelectrolyte Multilayer Films Using Chemically Modified Hyaluronic Acid and Poly(L-lysine) or Chitosan to Deliver the Hydrophobic Drug Paclitaxel.
Prathamesh Kharkar 1 , Thomas Boudou 1 , Jing Jing 2 , Di Cui 2 , Rachel Auzely-Velty 2 , Catherine Picart 1
1 Department of Bioengineering, Grenoble Institute of Technology, Grenoble France, 2 CNRS, CERMAV, Grenoble France
Show AbstractWorldwide, there are over 10 million new cases of cancer and more than 6 million deaths from cancer annually. Several anti-cancer drugs like paclitaxel (PTX) used for breast cancer treatment, have hydrophobic backbone chain and poor aqueous solubility, leading to reduced therapeutic efficiency of the drug. Optimization of present cancer treatment is important as it induces several side effects to other organs associated with drug and drug carrier. There is a crucial need to develop drug carriers that could decrease the toxic side effects and increase the water solubility. In the present work, polyelectrolyte films were constructed using the layer-by-layer assembly of chemically modified hyaluronic acid (HA) with induced hydrophobic nanocavities as anionic polyelectrolyte and quaternised chitosan (qCHI) or poly(L-lysine) (PLL) as cationic polyelectrolyte. The films were characterized using fluorescence and absorbance measurements. Paclitaxel was loaded inside the film in tunable amount depending on the number of deposited layers, the initial paclitaxel concentration and the nature of polycation. The films were further enzymatically hydrolyzed indicating biodegradability. The films demonstrated very high capacity of incorporating anticancer agent into hydrophobic nanocavities proving higher loading efficiency and release kinetics without initial burst. Next, the PTX-loaded PEM films were deposited on a biodegradable template to form polyelectrolyte hollow microcapsules. The metabolic activity and viability of MDA-MB231 breast cancer cells grown in the presence of the PTX-loaded microcapsules made of PLL and hydrophobic HA was then quantified. The bioactive microcapsules were found to be effective in blocking the proliferation of cancer cells. All together, these results suggest the potential of PEM-based microcapsules and films as carrier for cancer drug delivery.
9:00 PM - JJ5.20
Demonstration of Biocompatibility of Single Walled Carbon Nanotubes with Blood Leukocytes.
Krishna Kiran Medepalli 1 , Bruce Alphenaar 1 , Ashok Raj 2 , Palaniappan Sethu 3
1 Department of Electrical and Computer Engineering, Speed School of Engineering, University of Louisville, Louisville, Kentucky, United States, 2 Division of Pediatrics, School of Medicine, University of Louisville, Louisville, Kentucky, United States, 3 Department of Bioengineering, Speed School of Engineering, University of Louisville, Louisville, Kentucky, United States
Show AbstractSingle walled carbon nanotubes (SWNTs) possess unique structural and functional properties. Their ability to be functionalized with different biomolecules make them excellent candidates for biomedical applications like targeted drug delivery and cancer diagnostics [1]. However, prior to use in therapeutic applications, biocompatibility of SWNTs needs to be thoroughly investigated. Blood is a living tissue and contains cells which can potentially interact with SWNTs during the drug delivery process. The interaction of leukocytes in blood with the SWNTs can provide information regarding the immune response of the host to the nanotubes. Recently, we evaluated the acute immune response of leukocytes in blood to SWNTs via (a) direct interaction, due to the presence of SWNTs in circulation and (b) indirect interaction, due to the presentation of SWNTs to leukocytes via antigen presenting cells [2].These SWNTs were non-covalently functionalized with single stranded DNA (ss-DNA) that acts as a surfactant for suspending SWNTs in aqueous solutions and also serves as a backbone for attaching and transporting different biomolecules. Isolation of cells from blood was done using density gradient centrifugation. Early activation markers were used to study the activation of different leukocyte subpopulations and any activation results in changes of these markers. Flow cytometry was done to analyze the different subpopulations. Results of our study demonstrated that ss-DNA functionalized SWNTs do not elicit an immune response from leukocytes in blood via direct or indirect interaction. This intensive study demonstrates the biocompatibility of single walled carbon nanotubes and paves the way for their safe use in drug delivery and cancer therapeutics without cytotoxicity.References:[1] Nie, S., Xing, Y., Kim, G. J. & Simons, J. W. Nanotechnology Applications in Cancer. Annual Review of Biomedical Engineering (2007),9, 257-288.[2] Medepalli K., Alphenaar B., Raj A., Sethu P., Evaluation of the direct and indirect response of blood leukocytes to carbon nanotubes (CNTs), Nanomedicine (2011), doi:10.1016/j.nano.2011.04.002
9:00 PM - JJ5.21
The In Vitro Anticancer Activity of Nitrosyl Complexes Loaded in Biopolymer Nanoparticles.
Anderson Gomes 1 , Enilza Espreafico 3 , Elia Tfouni 2
1 Faculdade de Ceilandia, University of Brasilia FCE-UnB, Brasília Brazil, 3 Biologia Celular e Molecular e Bioagentes Patogênicos , Faculdade de Medicina de Ribeirao Preto-FMRP-USP, Ribeirao Preto Brazil, 2 Chemistry, Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto-FFCLRP-USP, Ribeirao Preto Brazil
Show AbstractIn this work, we describe the immobilization and characterization of trans-[Ru(NO)(NH3)4 py](BF4)3, trans-[Ru(NO)Cl(cyclam)](PF6)2(cyclam = 1,4,8,11-tetraazacyclotetradecane), and [Ru(NO)(Hedta)] (Hedta = ethylenediaminetetraacetic acid) entrapped in poly(D,L-lactic-co-glycolic) acid (PLGA) nanoparticles, by the double emulsification process. Scanning electron microscopy (SEM) and dynamic light scattering revealed that the particles are spherical in shape, have size distribution between 220 and 840 nm of diameter, and have tendency to aggregate confirmed by a zeta potential between -3.2 and +3.5 mV. Using this method the loading efficiency was 26% to trans-[Ru(NO)Cl(cyclam)](PF6)2 and 32% to [Ru(NO)(Hedta)]. The release of the complexes from nanoparticles shows that py-NP, cyclam-NP and Hedta-NP showed a biphasic release pattern, which was characterized by an initial complex burst during the first 24 h, followed by a slower release phase complex profile, due to a few pores observed in surface of nanoparticles using atomic force microscopy (AFM).The in vitro anticancer activity of nitrosyl complexes loaded PLGA nanoparticles on melanoma cancer cells (cell line WM 793) was investigated. PLGA nanoparticles loaded with trans-[Ru(NO)(NH3)4 py](BF4)3, trans-[Ru(NO)Cl(cyclam)](PF6)2 and [Ru(NO)(Hedta)] exerted in vitro a reduced anticancer activity against melanoma cells when compared to the activity of complex in solution (non-entrapped in nanoparticles). PLGA nanoparticles empty did not exhibit cytotoxicity. In the presence of light, WM 793 cells displayed a considerable damage of the cell surface by rupture of the cell membrane. This behavior is an indicative of the efficiency of the DDS to deliver the NO from the entrapped complex when photoinduced.Financial SupportFAPESP,CAPES,FAPDF,CNPq,FINATEC
9:00 PM - JJ5.22
Shell Cross-Linked Albumin Nanocapsules for Enhanced Intracellular Delivery of Paclitaxel.
Jeong Yu Lee 1 , Ki Hyun Bae 1 , Jee Seon Kim 1 , Yoon Sung Nam 1 2 , Tae Gwan Park 1
1 Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon Korea (the Republic of), 2 Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon Korea (the Republic of)
Show AbstractPaclitaxel, a well-known water-insoluble anti-cancer drug, has been formulated using polyethylated castor oil (Cremophor EL) and ethanol as delivery vehicles to increase its solubility. However, this oil-based formulation often shows acute side effects, such as hypersensitivity, neurotoxicity, and neuropathy. To reduce these side effects, a new formulation was developed by utilizing the high affinity of paclitaxel to human serum albumin (HSA) to produce a nanoscale, physical complex. In 2005, Abraxane, containing the paclitaxel/HSA complex, was approved by FDA. To further improve the efficacy of anti-cancer drugs via tumor targeting, multiple functionalized nano-carrier systems have also been proposed, including liposomes incorporating drug-polymer conjugates, lipid nano-emulsions, polymeric micelles, and biodegradable nanoparticles. It has been proved that these nano-carriers can increase the drug solubility in aqueous solution, colloidal stability, and injectability. Here we introduce an oil-free, shell cross-linked albumin nanocapsule as an efficient intracellular delivery system for paclitaxel. The nanocapsules were prepared by emulsifying amine-reactive six-arm-branched polyethylene glycol (PEG) in dichloromethane into aqueous solution of human serum albumin (HSA), followed by cross-linking at the organic/aqueous interface. Paclitaxel was successfully incorporated into the HSA/PEG nanocapsules having a spherical shape with an average diameter of about 280 nm. In several types of cells, the surface modification of nanocapsules with a cell-penetrating peptide, Hph1, greatly facilitated cellular uptake and apoptosis-inducing effects of paclitaxel. Furthermore, animal tumor model studies revealed that the paclitaxel-loaded HSA/PEG nanocapsules can preferentially accumulate in the tumor site, and thus can effectively suppress tumor growth upon i.v. administration. Because of the unique nano-reservoir structure for stable drug encapsulation and high tumor targeting specificity, the HSA/PEG nanocapsules can be potentially extended as delivery vehicles for other water-insoluble anti-cancer drugs to achieve effective cancer therapy by reducing the non-specific side effects to normal tissues.
9:00 PM - JJ5.24
Biocompatible Quantum Dot Conjugates and In Vivo Multiplexed near-Infrared Imaging System.
Nayoun Won 1 , Suk Ho Bhang 2 , Sanghwa Jeong 1 , Kangwook Kim 1 , Ho Jin 1 , Jutaek Nam 1 , Jungheon Kwag 3 , Joonhyuck Park 3 , Byung-Soo Kim 2 , Sungjee Kim 1 3
1 Department of Chemistry, Pohang University of Science and Technology, Pohang Korea (the Republic of), 2 Department of Bioengineering, Hanyang University, Seoul Korea (the Republic of), 3 School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang Korea (the Republic of)
Show AbstractQuantum dots (QDs) have proven the potential for imaging contrast agents by the bright luminescence, the resistance against photobleaching, and the multiplexing capability. We developed hyaluronic acid-quantum dot conjugates (HA-QDs) of hydrodynamic size from 50 to 120 nm via a simple and novel electrostatic coupling method. The HA-QDs showed specific binding to cancer cells expressing HA receptor LYVE-1, which suggests diagnostic and imaging applications. Using the HA-QDs in small animal model, lymphatic vessels were visualized real-time in vivo for days. Comprehensive cytoxicity evaluations were made for the conjugates and the unconjugated counterpart. The HA-QDs showcase the potentials toward real-time visualization of changes in lymphatic vessels such as lymphangiogenesis. Near-infrared (NIR) QDs can promise a new modality for in vivo bio-imaging and future medical imaging applications. We developed an in vivo real-time multiplexed NIR QD imaging system that has a Si CCD and an InGaAs CCD which in combination cover the NIR wavelength range from 700 to 1700 nm. Each CCD has a filter wheel with emission filters which enable the real-time multiplexed imaging of relatively slow events. To verify the capability for the surgical imaging applications, QD imaging capabilities were compared in the first optical window (FOW) at 700-900 nm using QDs that emit at around 800 nm (800QDs) and the second optical window (SOW) at 1000-1400 nm using QDs that emit at around 1300 nm (1300QDs), respectively. QD imaging depths in biological tissues such as bovine liver and porcine skin were investigated using the criteria of contrast-to-noise ratio and relative apparent size. In skin tissue, 800QD/FOW had imaging depth of 4.2 mm; under the same conditions, 1300QD/SOW showed imaging depth of 11.6 mm. Due to the reduced scattering in SOW, the imaging depth in skin can be extended by ~3 times for 1300QD/SOW. In liver tissue, although 1300QD/SOW imaging and 800QD/FOW imaging showed similar imaging depths, the imaging depth of 1300QD/SOW imaging could be extended with longer excitation wavelengths by reducing the absorption of the illuminating photons. Effects of quantum yield (QY), concentration, incidence angle, polarization and fluence rate F on imaging depth were quantified, and results were used to estimate imaging depths by 1300QD/SOW under hypothetical conditions. Under optimal conditions using continuous excitation at the FDA approved F, 1300QDs with 50 % QY may reach imaging depths of 29.7 mm in liver and 17.5 mm in skin tissue. To validate our estimates, imaging capabilities of QDs were compared using in vivo whole-body imaging of mice. Time-gated excitations with high F, software optimization of QD imaging, and advances in sensitivity of cameras in SOW are expected to further increase the imaging capability of QDs in SOW.
9:00 PM - JJ5.25
Polyvalent Nucleic Acid Nanostructures: Novel Single-Entity Gene Regulation Agents.
Joshua Cutler 1 , Ke Zhang 1 , Dan Zheng 1 , Evelyn Auyeung 2 , Andrew Prigodich 1 , Chad Mirkin 1 2
1 Department of Chemistry, Northwestern University, Evanston, Illinois, United States, 2 Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois, United States
Show AbstractThe natural defenses of biological systems for exogenous oligonucleotides, such as synthetic antisense DNA and siRNA, present many challenges for the delivery of nucleic acids in an efficient, non-toxic, and non-immunogenic fashion. Indeed, because nucleic acids are negatively charged and prone to enzymatic degradation, researchers have historically relied on transfection agents such as cationic polymers, liposomes, and modified viruses to facilitate cellular entry and protect DNA from degradation. However, each of these materials is subject to several drawbacks, which include toxicity at high concentrations, inability to be degraded biologically, and severe immunogenicity. The recently introduced polyvalent nucleic acid nanoparticle (NP) conjugates (inorganic NPs densely coated with highly oriented oligonucleotides) pose one possible solution for circumventing these problems in the context of both antisense and RNAi pathways. Remarkably, these highly negatively charged structures (zeta potential < -30 mV) do not require cationic transfection materials or additional particle surface modifications and naturally enter all cell lines tested to date (over 50, including primary cells). Further work has shown the cellular uptake of these particles to be dependent upon DNA surface density: higher densities lead to higher levels of particle uptake. The high-density polyvalent nucleic acid surface layer is believed to recruit scavenger receptors from the cells that facilitate endocytosis. Moreover, the ion cloud associated with the high-density oligonucleotide shell, combined with steric inhibition at the surface of the particles, inhibits enzymatic nucleic acid degradation and activation of the enzymes that trigger the innate immune response of certain cells. These surprising observations pose the question, will polyvalent nucleic acids alone (lacking a particle core) readily enter cells without the need for a cationic polymer co-carrier? If so, one could create new gene regulation, drug delivery, and imaging systems based solely on high-density polyvalent nucleic acid nanostructures (PNANs) and bypass some of the issues that surround inorganic particle-based systems, especially those pertaining to long-term toxicity. Herein, we demonstrate a strategy for synthesizing monodisperse, spherical high-density polyvalent DNA and DNA/RNA hybrid nanostructures with no inorganic cores, using a novel gold nanoparticle-mediated alkyne-crosslinking reaction our group has discovered. These new nanostructures are composed entirely of oligonucleotides, maintain the unique binding properties of nucleic acid-inorganic NP conjugates, exhibit the ability to enter cells without co-carriers, and engage the RNAi pathway in human cells.
9:00 PM - JJ5.27
Breast Adenocarcinoma Cell Behaviors on PLGA Nanometer Surface Features.
Lijuan Zhang 1 , Thomas Webster 1
1 , Brown University, Providence, Rhode Island, United States
Show AbstractPoly (lactic-co-glycolic acid) (PLGA) has been widely used as a biomaterial due to its good biocompatibility and biodegradability. Many studies have shown that cells (such as bladder smooth muscle cells, chondrocytes and osteoblasts) respond differently to nano-structured PLGA surfaces compared to nano-smooth surfaces. Thus, this study investigated breast adenocarcinoma cell viability and VEGF (vascular endothelial growth factor) secretion on nano-featured PLGA for up to 5 days. Briefly, different size (specifically, 23 nm, 300 nm and 400 nm diameter) polystyrene beads were placed onto glass coverslips to create highly ordered monolayers to cast poly (dimethylsiloxane) (PDMS) molds. The molds were further used as templates to create nano-featured PLGA films. Nano-smooth PLGA films were casted on the PDMS molds without PS monolayers as controls. AFM images of the various PLGA surfaces provided evidence that the intended spherical surface topographies were created using the methods described above. Then, breast adenocarcinoma cells (MCF-7; ATCC) were seeded on the resultant PLGA samples at a density of 100,000 cell/cm2 cultured in Eagle's Minimum Essential Medium (EMEM) with 10% fetal bovine serum (FBS) at 5% CO2 and 37oC. The celltier 96® non-radioactive cell proliferation assay kit (Progema) was used to determine the viability of the cultured cells after 1, 3 and 5 days. Breast adenocarcinoma cells showed lower viability (less viable cell numbers) on the 23 nm surface-featured PLGA films compared to any other PLGA films after 1, 3 and 5 days. Furthermore, breast adenocarcinoma cells were seeded on the PLGA samples at a density of 500,000 cell/well in 24 well plates for up to 5 days. The medium for the VEGF measurements were collected after 1, 3 and 5 days of the culture process. The quantikine human VEGF immunoassay kit (R&D systems) was used for determining VEGF concentration. After one day, VEGF concentrations showed no significant difference between different nano-featured PLGA surfaces. However, as culture time increased, the cells secreted different amounts of VEGF. Cells on the 23 nm surface featured PLGA secreted significantly less VEGF than on any other PLGA films after 3 and 5 days, suggesting decreased breast adenocarcinoma cell functions on such nano-featured PLGA films. VEGF results could be explained by the lower cell viability on the 23 nm surface-featured PLGA films found in the above MTT assay. In this way, the 23 nm surface featured PLGA can decrease breast adenocarcinoma cell proliferation and VEGF synthesis, demonstrating that specific PLGA nanometer surface features (23 nm in this study for breast adenocarcinoma cells) should have potential applications in inhibiting cancer cell functions.
9:00 PM - JJ5.28
Probing the Distance-Dependent Sensitivity of Plasmonic Biosensors Using Layer by Layer Assembly.
Max Fei 1 , Limei Tian 1 , Ramesh Kattumenu 1 , Srikanth Singamaneni 1
1 Mechanical Engineering and Material Sciences, Washington University in St. Louis, Saint Louis, Missouri, United States
Show AbstractPlasmonic biosensors are gaining immense interest as promising platform for label-free, non-invasive and point-of-care diagnosis and prognosis of cancer. Localized surface plasmon resonance (LSPR) of metal nanostructures, which is sensitive to changes in the local refractive index , is rapidly emerging as a powerful biodetection technique. LSPR was shown to be sensitive enough to differentiate various inert gases (refractive index difference on the order of 3×10-4), probe the conformational changes of individual biomacromolecules, detect single biomolecule binding events, monitor the kinetics of catalytic activity of single nanoparticles and even optically detect single electron. The ability to probe the distance dependent sensitivity of plasmonic nanostructures and their assemblies is paramount to design and optimize transducers for highly sensitive biosensors. In this work, we demonstrate that layer by layer assembly of polyelectrolytes, which offers excellent control over the thickness (down to 1 nm) of the organic layer, can be employed for probing the distance-dependent refractive index sensitivity of plasmonic nanostructure assemblies. In particular, we demonstrate that the coupled plasmon resonance of metal nanoparticle chains exhibits nearly 300% higher refractive index sensitivity and figure of merit compared to the LSPR of the individual nanoparticles and nanorods. We believe that the approach demonstrated here will serve as a facile tool for design and optimization of plasmonic transducers for label-free point-of-care cancer diagnostics.
9:00 PM - JJ5.29
Gold-Iron Oxide Bifunctional Nanoparticles for Dual Diagnostic Imaging of Pancreatic Cancer.
Don Ho 1 , Zhenglong Yuan 2 , Kai Cheng 1 , Edward Walsh 3 , Maureen Chung 2 , Shouheng Sun 1
1 Chemistry Department, Brown University, Providence, Rhode Island, United States, 2 Departmentof Surgery, Warren Alpert Medical School, Providence, Rhode Island, United States, 3 Department of Neuroscience, Brown University, Providence, Rhode Island, United States
Show AbstractGold-iron oxide nanoparticles have intrinsic properties of MRI contrast and differential surface functionalization making them ideal for diagnostic and future therapeutic applications. The gold-iron oxide dumbbell-like structure allows for controlled chemistry on either surface independently and both iron oxide and gold are biocompatible. Iron oxide has magnetic properties with diagnostic use in MRI, while we also explore gold as an optical diagnostic probe. With the ability to differentially functionalize the surface of this nanoplatform, wehave added the MUC1 targeting agent present in human pancreatic tumors. We examine the diagnostic imaging of our gold-iron oxide nanoparticles with pancreatic cancer tumors in an immunodeficient mouse model using the tumor marker, MUC1.
9:00 PM - JJ5.3
Design and Application of Modified Gold Nanoparticles in Cancer Diagnosis and Therapy.
Ieda Paino 1 , Valeria Marangoni 1 , Valtencir Zucolotto 1
1 Nanomedicine and Nanotoxicology Laboratory, Physics Institute of São Carlos - Universidade de Sao Paulo, São Carlos, São Paulo, Brazil
Show Abstract Engineered Nanomaterials (ENMs) have been extensively explored as novel active materials and devices in medicine. The latter refers to the use of nanomaterials in diagnosis, smart delivery and cancer therapy, in which the nanomaterials, including nanoparticles and carbon nanotubes, are conjugated with biomolecules capable of targeting specific organs and cells. These nanocomposites exhibit enhanced physico-chemical properties that make them suitable for either in vivo or in vitro applications. In the last years, our research group has manipulated various biomolecules-conjugated nanomaterials, including nanotubes and metallic nanoparticles for applications in Medicine. This paper describes the use of gold nanoparticles (AuNPs) complexed with polyamidoamine dendrimers (PAMAM G4), which induced cytotoxicity and genotoxicity in HepG2 Human hepatocellular liver carcinoma cells, in a concentration-dependent manner. A significant cyto and genotoxic response (p<0.05) was observed for concentrations from 1 to 50.0 uM. Furthermore, the toxic effect of the PAMAM-modified nanoparticles against the tumor cells was significantly higher than that exhibited by conventional citrate-covered AuNPs. These encouraging results represent an important step forward in using AuNps nanocomplexes in medicine.
9:00 PM - JJ5.30
Plasmonic Paper as a Novel Biosensing Platform.
Limei Tian 1 , Ramesh Kattumenu 1 , Srikanth Singamaneni 1
1 Mechanical Engineering and Materials Science, Washington University in St.Louis, St.Louis, Missouri, United States
Show AbstractState of the art localized surface plasmon resonance biosensors rely on micro and nanofabrication on solid substrates for spectrally homogenous sensing medium. We demonstrate common filter paper as a novel platform for plasmonic biosensing, which offers numerous advantages compared to conventional transparent substrates such as compatibility with conventional printing approaches (enabling multiplexed detection and multi-marker biochips), high specific surface area (resulting in large dynamic range), excellent wicking properties (naturally microfluidic) and significant reduction in cost. Plasmonic paper, which involves uniform decoration of paper substrates with functionalized metal nanostructures, exhibited excellent spectral homogeneity and high refractive index sensitivity. Protein A-functionalized gold nanoparticles enabled the detection of extremely low concentrations of IgGs (down to 1pg/ml). We believe that plasmonic paper will open up a novel avenue in LSPR based biosensing for realizing simple, inexpensive and highly sensitive biochips.
9:00 PM - JJ5.31
Poly(Ethylene Glycol) - Polycaprolactone Diblock Micelles with RGD Targeting Ligands and Embedded Iron Oxide Nanoparticles for Thermally-Activated Release of Doxorubicin.
Christopher Brazel 1 , James Bennett 1 , Amanda Glover 2 , Jacqueline Nikles 3 , Maaike Everts 4 , Joel Glasgow 4 , David Nikles 2
1 Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama, United States, 2 Chemistry, The University of Alabama, Tuscaloosa, Alabama, United States, 3 Chemistry, The University of Alabama at Birmingham, Birmingham, Alabama, United States, 4 Medicine, The University of Alabama at Birmingham, Birmingham, Alabama, United States
Show AbstractA thermally-activated micelle consisting of a crystallizable poly(caprolactone), PCL, core and poly(ethylene glycol), PEG, corona was developed to contain magnetic nanoparticles and anti-cancer agent doxorubicin and include a targeting RGD peptide. This system has the potential to be used to target cancer cells, deliver combination hyperthermia and chemotherapy, and offer magnetic resonance imaging contrast. The micelles self-assemble in aqueous solutions and form a crystalline core with a melting transition ranging from 40 to 50 oC, depending on the length of the PCL blocks, with dynamic light scattering showing micelle sizes typically ranging from 20 to 100 nm, depending on block lengths and added drug or nanoparticles. The micelles become unstable as they are heated above their melting point, creating a thermally-activated drug release mechanism. By adding magnetite (Fe3O4) nanoparticles into the PCL core, the micelles can be heated using an externally applied AC magnetic field to induce hyperthermia in combination with the thermally-activated drug release. The polymers and nanoparticles were synthesized and characterized in our laboratories. The melting transitions of the PCL micelle cores were investigated using microcalorimetry. The fluorophore pyrene was used to confirm critical micelle concentrations, and doxorubicin HCl was loaded into the micelles during self-assembly. The heating of nanoparticles and magnetomicelles was conducted using a custom-built hyperthermia coil capable of generating fields of several hundred Gauss at frequencies ranging from 50 to 450 kHz. RGD peptides were attached to the PEG corona using maleimide chemistry, and the ability of the RGD-derivatized micelles to target integrin-expressing cells was investigated in vitro using fluorescent dye PKH26 to identify the localization of micelles in cultured human kidney (293) cells. The crystallizable (and meltable) cores in these micelles was designed to overcome drug leakage common in liposome systems and release the drug on demand after a period of time for localization to integrin receptors.
9:00 PM - JJ5.32
Stable Colloids of Paclitaxel Nanoparticles Coated with PEGylated Polyelectrolytes Shells.
Tatsiana Shutava 1 , Kirill Arapov 1 , Pravin Pattekari 1 , Yuri Lvov 1 , Tatyana Levchenko 2 , Rupa Sawant 2 , Vladimir Torchilin 2
1 Institute for Micromanufacturing, Louisiana Tech University, Ruston, Louisiana, United States, 2 Department of Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts, United States
Show AbstractA novel nanoparticulated form of poorly water-soluble anticancer drug paclitaxel suitable for intravenous administration has been developed using sonication-assisted bottom-up layer-by-layer (LbL) assembly. The nanoparticles contain up to 80 wt.% of the drug and consist of 150-180 nm solid crystal paclitaxel cores coated with 20-30 nm thick shells of alternative layers of PEGylated poly-L-lysine (PLL) and heparin.Paclitaxel was initially dissolved in acetone and less than 100 µL of the concentrated solution was added to a 40 times larger volume of the PBS buffer containing polyvinylpyrrolidone, sodium docusate, and Polysorbate 80 under constant sonication to prevent the formation of larger particles. The drug nanocores were coated in the supernatant containing aforementioned excipients with polyelectrolyte layers using a washless LbL procedure. Each polyelectrolyte was sequentially added under constant sonication in the amount adequate to completely reverse the nanoparticles surface charge to an opposite value; the assembly was followed by zeta-potential measurements. The coated nanoparticles of a ca. 200 nm diameter were separated from the supernatant by centrifugation, redispersed in the PBS buffer, and kept as stable colloids of 3-5 mg/mL (as paclitaxel) concentration. It has been found experimentally that two PEGylated substances (Polysorbate 80 and PEGylated PLL) are central in stabilizing LbL-coated paclitaxel nanoparticles in salt-containing buffers. The usage of a mixture of surfactants allowed stabilizing drug nanocores in concentrated suspensions. PLL(16kDa)-block-PEG(5kDa) copolymer, as a substitute of unPEGylated PLL of low molecular weight, allowed to avoid aggregation upon alternated adsorption with heparin on nanoparticles surface, while an outermost layer of PLL (65kDa)-graft [4.5]-PEG (5kDa) further enhanced the nanoparticle colloidal stability. The prepared LbL-coated paclitaxel nanoparticles are colloidally stable in PBS buffer at room temperature up to 150 h.The in vitro release studies for the paclitaxel nanocolloids were done under sink conditions at 37 °C in the PBS buffer containing 0.2 mg/mL Polysorbate 80 added to increase drug solubility limit. For paclitaxel nanoparticles prepared via the bottom-up approach and coated with different number of PLL(16 kDa)-block-PEG(5 kDa)/heparin bilayers, no distinguishable influence on release were found for shells consisting less than 3.5 bilayers. In another experiment with paclitaxel nanoparticles prepared via the top-down sonication assisted LbL technique, 4, 8 and 12 bilayers of unPEGylated PLL and heparin slightly decreased the drug release rate as compared with nanocolloids coated with only one PLL layer.The experiments on administration of the LbL-coated paclitaxel nanoparticles in mice via the tail vein provided the preliminary confirmation of their safety and tolerability.The work was supported by the NIH grant #1R01CA134951 to Vladimir P. Torchilin.
9:00 PM - JJ5.33
A Virus-like Particle Platform for Affinity Selection and Targeted Delivery of Therapeutics.
Mekensey Buley 1 , Carlee Ashley 2 , Walker Wharton 3 , David Peabody 4 , Jeffrey Brinker 5 6
1 Biomedical Engineering, University of New Mexcio, Albuquerque, New Mexico, United States, 2 Biotechnology and Bioengineering, Sandia National Labs, Albuquerque, New Mexico, United States, 3 Pathology, University of New Mexico, Albuquerque, New Mexico, United States, 4 Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, New Mexico, United States, 5 , Sandia National Labs, Albuquerque, New Mexico, United States, 6 Chemical and Nuclear Engineering, University of New Mexico, Al, New Mexico, United States
Show AbstractWith the development of nanoparticle technology and advanced understanding of cancer development and differentiation, targeted drug delivery has become a major goal. Many existing nanocarriers use targeting peptides identified by phage display, which are then produced synthetically and conjugated to the surface of a nanocarrier. Unfortunately, transfer of the peptide to a different structural environment frequently results in reduced peptide affinity for the targeted receptor. Using virus-like particles of bacteriophage MS2, we have developed a platform that serves both as drug delivery vehicle and as a platform for affinity selection of targeting peptides from random sequence libraries, thus integrating both functions into a single particle. The structural context present during affinity optimization of a targeting peptide is strictly preserved during delivery.The goal, then, is to conduct affinity selections on cellular targets. But cells generally present a complex population of receptors, the vast majority of which are not specific to the target cell. Therefore, we created a system that allows us to conduct counter-selections against cells specifically lacking the targeted receptor. As an example, consider the thymic stromal lymphopoietin receptor, CRLF2, a protein over-expressed on cells of high-risk pediatric Acute Lymphoblastic Leukemia patients. By over-expressing the CRLF2 gene in BaF3 cells we produced a cell line for positive selection of CRLF2-targeting peptides. Meanwhile, the parental BaF3 cells provide an ideal counter-selection by specifically lacking CRLF2. Experiments are now underway to work out the best methods for peptide selection on MS2 VLPs.Here we describe preliminary experiments that optimize the presentation CRLF2-targeting peptides already identified by conventional phage display. We report results dealing with such issues as the best means of ensuring peptide accessibility, methods for reducing non-specific interactions with cells, the behaviors of conformationally constrained versus unconstrained peptides, etc. We are also determining the binding characteristics of VLPs to CRLF2-expressing cells and the mechanisms and kinetics of particle internalization.This work is supported by the Excellence in Engineering Research Fellowship and the Laboratory Directed Research and Development Program at Sandia National Laboratories. Sandia is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.
9:00 PM - JJ5.34
Cytotoxic and Anti-Cancer Effects of Nickel Nanowires against Pancreatic Cancer Cells.
Md. Zakir Hossain 1 , Wisam Khudhayer 2 , Rozina Akter 1 , Tansel Karabacak 3 , Maurice Kleve 4
1 Applied Biosciences, Department of Applied Science, University of Arkansas at Little Rock, Little Rock, Arkansas, United States, 2 Department of Systems Engineering, University of Arkansas at Little Rock, Little Rock, Arkansas, United States, 3 Department of Applied Science, University of Arkansas at Little Rock, Little Rock, Arkansas, United States, 4 Department of Biology, University of Arkansas at Little Rock, Little Rock, Arkansas, United States
Show AbstractCytotoxicity study of magnetic nanomaterials is a key consideration for biomedical applications. Very little is known about the cytotoxic and anti-cancer effects of nickel nanowires (Ni NWs) on mammalian cells and their interaction with proliferating cancer cells. Current therapeutics does not reflect the full heterogeneity of pancreatic cancers due to the resistance to apoptosis and does not suffice for a successful treatment. Therefore, synthesis of novel anticancer drugs continues to be a potential aspect of pancreatic cancer research. In this study, we have investigated the cellular toxicity and anti-cancer effects of Ni NWs in one of the most aggressive human pancreatic ductal cancer (Panc-1) cell lines with the objective of development of a potential treatment strategy. Ni NWs were fabricated in a custom-made setup utilizing the electrodeposition method. Elemental analysis, crystallographic structure, and morphological properties of the synthesized Ni NWs were investigated using Energy Dispersive X-ray Analysis (EDAX), X-Ray Diffraction (X-RD)and Scanning Electron Microscopy(SEM).Panc-1 cell cultures were maintained according to a slightly modified American Type Culture Collection (ATCC) protocol. Morphological apoptogenic characteristics assessment of the Ni NWs induced Panc-1 cell was accomplished using phase contrast microscopy (PCM). Two commercially available and straight forward distinct cytotoxicity procedures including 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) and Trypan Blue (TB) Assay were utilized to determine the qualitative and quantitative cytotoxicity and anti-cancer effects of Ni NWs. As a negative control, Panc-1 cells without Ni NWs treatment were used in all experiments. Phase contrast microscopy was used to confirm the Ni NWs internalization by Panc-1 cells. Both the MTT and TB assays, qualitatively and quantitatively confirmed the cytotoxic and anti-cancer effects of Ni NWs treated Panc-1 cells in vitro in concentration and exposure-time dependent manners. We studied the cytotoxic and anti-cancer effects of Ni NWs on Panc-1 cells using novel integrated bionanotechnological approaches to understand the corresponding biological pathway with an aim of pancreatic cancer treatment. More specifically, we explored the molecular mechanisms associated with the pathway involved in Ni NWs induced toxicity against Panc-1 cells. Our results demonstrated that Ni NWs show strong candidacy for targeting cell selective applications in bio-nanomedicine, especially in pancreatic cancer therapy.
9:00 PM - JJ5.35
Symmetry Breaking of Plasmonic Nanoparticles in a Solution.
Eunhye Jeong 1 , Kihoon Kim 1 , Younggeun Park 1 , Yeonho Choi 2 , Hyunjoo Lee 3 , Taewook Kang 1
1 , Sogang University, Seoul Korea (the Republic of), 2 , Korea University, Seoul Korea (the Republic of), 3 , Yonsei University, Seoul Korea (the Republic of)
Show AbstractThe metallic nanoparticles with symmetry-broken shape have received increasing interest as a potential material for plasmonics due to unique electromagnetic property. Recently, many researchers have proposed methods to fabricate these asymmetric nanoparticles on a 2-dimensional plane by using ion milling and metal deposition. However, these methods are limited in in-vivo application compared to the wet chemical synthesis method. Here, we suggest an innovative way of breaking the symmetry of nanoparticle in a solution. Our strategy consists of two steps : (i) Formation of metal/non-metal dimeric nanoparticle, (ii) Selective overgrowth of metal. While selective overgrowth in process, non-metal on the dimer prevents isotropic overgrowth of metal part. As a proof of concept, asymmetric gold nanoparticles in a solution are synthesized by Au overgrowth on gold/PS dimeric nanoparticle. In this work, the effect of concentration of metal precursor, type of reducing agents, and the size of PS on overgrowth are tested. We also discuss growth mechanism of gold nanoparticle during overgrowth reaction.
9:00 PM - JJ5.36
Low Power, Biologically Benign NIR Light Triggers Polymer Backbone Disassembly.
Adah Almutairi 1 , Nadezda Fomina 1
1 , University of California San Diego, La Jolla, California, United States
Show AbstractDespite promise in various biomedical applications, only a handful of biomaterials degrade under NIR irradiation. None do so under low power NIR irradiation which is biologically benign. We report here a polymeric material that undergoes backbone disassembly into small molecules in response to low power NIR irradiation. Photolysis of multiple 4-bromo7-hydroxycoumarin protecting groups pendant to the polymer backbone triggers a cascade of cyclization and rearrangement reactions leading to polymer backbone degradation.
9:00 PM - JJ5.38
Förster Resonance Energy Transfer Detection of DNA Hybridization and Fluorescence Imaging of Live Cells Using Hydroxylated Nanocrystals.
Seung Koo Shin 1 , Yongwook Kim 1 , Hye-Joo Yoon 1
1 Chemistry, POSTECH, Pohang Korea (the Republic of)
Show AbstractHighly sensitive fluorescence detection of DNA hybridization is of value in gene expression analyses and in clinical diagnostics. Hydroxylated semiconductor nanocrystals are bright, biocompatible, and nonspecific interaction-free in biological settings. Herein, we report the use of hydroxylated nanocrystals as fluorescent probes for the ultrasensitive detection of DNA hybridization on a DNA chip with detection sensitivity 10–100 times greater than the conventional organic dyes. The detection sensitivity was examined on a meso-spacing DNA chip by using a micro array scanner or a fluorescence microscope. Target DNA was immobilized on a chip, and probe DNA with a fluorescent label or biotin was hybridized to target DNA. Hydroxylated nanocrystals were made by passivating zinc-blende CdSe/ZnS nanocrystals with 3-mercapto-1-propnaol and conjugated with amine-functionalized DNA or biotin via N,N′-disuccinimidyl carbonate. For comparison, both Cy3–DNA and Cy3–biotin were employed. Biotinylated probe DNA was detected either with biotinylated nanocrystals or with Cy3–biotin via biotinylated DNA–streptavidin–biotinylated fluorophore interactions. Detection sensitivity of 10 zmol DNA was achieved on a single spot on the chip using biotinylated nanocrystals. Furthermore, hybridization of target and probe DNAs was confirmed by Förster resonance energy transfer (FRET) between biotinylated nanocrystals clustered on probe DNA and Cy3 dye conjugated on target DNA. Although Cy3 alone bleaches fast upon direct photoexcitation, a nanocrystal–Cy3 donor–acceptor FRET pair makes Cy3 dye less susceptible to photobleach. Lastly, hydroxylated nanocrystals were used to label A431 human carcinoma cells to demonstrate background-free imaging of live cells.
9:00 PM - JJ5.4
Synthesis and Characterization of Magnetite Nanoparticles Modified with PEG-Based Amphiphilic Copolymers.
Ryo Kasuya 1 , Teppei Kikuchi 2 , Jeyadevan Balachandran 3
1 , National Institute of Advanced Industrial Science and Technology, Nagoya Japan, 2 , Graduate School of Environmental Studies, Tohoku University, Sendai Japan, 3 , School of Engineering, University of Shiga Prefecture, Hikone Japan
Show AbstractMagnetic fluid hyperthermia is a type of cancer therapy which induces the necrosis of cancer cells by thermal stress caused by raising the temperature above 43°C, utilizing the heat dissipated from magnetic nanoparticles (MNPs) exposed to an alternating current (AC) magnetic field. However, the MNPs work as thermal seeds in human tissues are required to possess (1) high heating efficiency, (2) hydrophilic property and (3) tumor-specificity. Thus in this study, we have focused on the preparation of aqueous suspension dispersing PEG chained amphiphilic copolymers modified MNPs with high heat efficiency. MNPs were prepared by thermally decomposing Fe(III) acetylacetonate (Fe(acac)3) in a solvent composed of oleic acid (OA) and oleylamine (OM). The particulate properties of MNPs depended on reaction temperature and content of Fe(acac)3 for a fixed OA/OM ratio. According to the transmission electron microscopic analysis, the primary particle size increased from 6.6±0.6 nm (sample A) to 12.5±1.4 nm (sample B) when the reaction temperature was increased from 200°C to 250°C. In contrast, the particle diameter was only 8~9 nm when reaction temperature was 300~320°C.The x-ray diffraction pattern corresponded to magnetite phase, and average particle sizes obtained from TEM observation were in agreement with the crystallite sizes calculated by Scherrer's equation. Fourier-transformed infrared (FT-IR) spectra indicated that the poor dispersibility of the as-synthesized particles in aqueous solution was due to the adsorption of lipophilic molecules such as oleic acid and oleylamine on their surfaces.Therefore, we modified the particle surface by amphiphilic copolymer composed of poly(maleic anhydride-alt-1-octadecene) (PMAO) and polyethylene glycol methyl ether (PEGME). After surface modification, a stable suspension was obtained by transferring the particles from organic phase to aqueous buffer solution. The presence of characteristic FT-IR peaks corresponding to free carbonyl groups implied that magnetite nanoparticles have been successfully modified with PMAO-PEGME amphiphilic copolymer. In addition, the obtained dispersion did not show any significant sedimentation during centrifugation at 15,000 rpm for 30 min. We also investigated the heat dissipation characteristics of magnetite dispersion under AC magnetic field (magnetic field strength: 40 Oe at 600 kHz). After irradiation of AC magnetic field, the sample B showed a temperature rise of 9°C. On the other hand, the sample A did not show any significant heat. These results show that the magnetite particle with diameter of 12 nm is applicable for the thermal therapy such as hyperthermia treatment. To acquire the cancer targeting ability, conjugations between MNPs and the antibody is in progress.
9:00 PM - JJ5.40
Biologically Active siRNA-Based Nanostructured Particles for Efficient Gene Silencing.
Cheol Am Hong 1 , Soo Hyeon Lee 1 , Jee Seon Kim 1 , Ji Won Park 1 , Ki Hyun Bae 1 , Yoon Sung Nam 1 2 , Haeshin Lee 3 , Tae Gwan Park 1
1 Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon Korea (the Republic of), 2 Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon Korea (the Republic of), 3 Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon Korea (the Republic of)
Show AbstractDNA has been exploited as excellent molecular building blocks for fabricating a wide range of two-, three-dimensional nanostructures with different sizes, shapes, and patterns due to its highly specific complementary base pairing. A variety of predictable nanoarchitectures including grids, cubes and polyhedra could be readily constructed in a precisely controlled manner by rationally designed DNA strands. DNA-based dendrimers and hydrogels were also synthesized by using Y-shaped, trimeric DNA molecules that serve as crosslinkers for self-assembling two or more designed sequences via ligase-mediated reactions. Although the self-assembled DNA nanostructures and hydrogels exhibit a variety of structures with well-defined geometry, they generally do not show any biological activities in a molecular and cellular level. Small interfering RNA (siRNA), double-stranded (ds) RNA molecules with 21 ~ 27 base pairs, has recently emerged as a powerful tool for silencing a target gene. Compared to single-stranded (ss) antisense oligonucleotides, siRNA has shown enhanced efficient gene silencing in a sequence-specific manner with a low dose. In this study, the first attempt to prepare biologically active siRNA-based microparticles showing superb gene silencing activities was made through hybridization between ss sense and antisense siRNA containing Y-shaped siRNA branches as hinge-like crosslinkers without enzyme-catalyzed ligation. The siRNA microparticles showed porous and well-dispersed spherical morphology having a network structure of the cross-linked siRNAs. These siRNA microparticles with greatly enhanced charge densities were collapsed to form compact nano-sized complexes upon interacting with a popular cationic carrier, linear polyethylenimine (LPEI, MW 2,500). The stable complexes exhibited superb intracellular uptake and gene silencing activities without severe cytotoxicities. The engineering siRNA microparticles hold great potentials as a new class of nucleic acid platform materials for therapeutic applications.
9:00 PM - JJ5.41
Artificial Triggering of Cell Signaling and Growth via Magnetic Nanoparticles.
Mi Hyeon Cho 1 , Jae-Hyun Lee 1 , Eun Jung Lee 1 2 , Jeon-Soo Shin 2 , Jinwoo Cheon 1
1 Department of Chemistry, Yonsei University, Seoul Korea (the Republic of), 2 Department of Microbiology, College of Medicine, Yonsei University, Seoul Korea (the Republic of)
Show AbstractArtificial control of cellular activities is of high interest in biomedical science. The activation of receptors on the cells is typically driven by biochemical ligands: however, nanoscale tools can also perform such a role. Here, we report nanoscale-magneto-activated cellular signaling (N-MACS) for receptor mediated angiogenesis which is a vital process related to the formation of blood vessels and cancer metastasis. Instead of using natural ligands for angiogenesis, in our study a Zn2+-doped iron oxide magnetic nanoparticle is employed to target and magnetically manipulate Tie2 receptors through the angiogenesis signal pathways. Target specific antibody and magnetic nanoparticle conjugates, which are first bound to Tie2 receptors on cell surfaces, are clustered by translational forces exerted through external magnetic field. Such mechano-cell activations are confirmed by identifying down-stream cell signaling signatures including phosphorylations of Tie2, Akt, and reactive oxygen species. This phenomenon serves as a “trigger-on” for a number of Tie2 related intracellular signaling events that cause human umbilical vein endothelial cells (HUVECs) to undergo tubulogenesis, which is the pre-angiogenesis stage. Our results suggest that vascular-specific cellular activities can be controlled in a remote and precise fashion via molecular-level N-MACS approach.
9:00 PM - JJ5.42
Accurate Cell Tracking with Hybrid-Nanoparticle Based MR Contrast Agent.
Tae-Hyun Shin 1 , Jin-sil Choi 1 , Dongwon Yoo 1 , Jinwoo Cheon 1
1 Department of Chemistry, Yonsei University, Seoul Korea (the Republic of)
Show AbstractIn vivo MR cell tracking with magnetic nanoparticles has been widely studied due to its potential of being powerful technique to determine the history and the fate of cells and to evaluate cell-based therapies. SPIO and USPIO are representative cell labeling agents. However they still possess fundamental limitation because negative signal from agents is hard to be distinguished from hypointense signals caused by various physiological artifacts including hemorrhage, calcification, and air-bubbles. This problem can provide false information in cellular tracking. Here, we report hybrid-nanoparticle as cell labeling agents which are free from false signals arised from various artifacts. They possess greatly enhanced contrast effect compared to conventional agents. Stem cells are successfully labeled with developed hybrid nanoparticles without any toxic effects and their signals are maintained for several periods of cell proliferation. The hybrid nanoparticles labeled stem cells are imaged by using MRI, their signals are clearly distinguished from fault signals. The hybrid nanoparticles developed here, have great potential in applications for labeling of various cell types and also for the monitoring of cell based medical treatments.
9:00 PM - JJ5.43
Quantifying the Single Cell Traction Force by Aligned Silicon Nanowire Array.
Zhou Li 1 2 , Jinhui Song 2 , ZhongLin Wang 2
1 , Beihang University, BeiJing China, 2 , Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractThe physical behaviors of stationary cells, such as the morphology, motility, adhesion, anchorage, invasion and metastasis, are likely to be important for governing their biological characteristics. A change in the physical properties of mammalian cells could be an indication of disease. Here, we present a silicon-nanowire-array based technique for quantifying the mechanical behavior of single cells representing three distinct groups: normal mammalian cells, benign cells (L929), and malignant cells (HeLa). By culturing the cells on top of NW arrays, the maximum traction forces of two different tumor cells (HeLa, L929) have been measured by quantitatively analyzing the bending of the nanowires. The cancer cell exhibits a larger traction force than the normal cell by ∼20% for a HeLa cell and ∼50% for a L929 cell. The traction forces have been measured for the L929 cells and mechanocytes as a function of culture time. The relationship between cells extending area and their traction force has been investigated. Our study is likely important for studying the mechanical properties of single cells and their migration characteristics, possibly providing a new cellular level diagnostic technique.
9:00 PM - JJ5.44
Multicomponent Mesoporous Silica Nanoparticles from Surfactant Self-Assembly.
Hiroaki Sai 1 , Teeraporn Suteewong 2 , Sol Gruner 3 , Michelle Bradbury 2 , Ulrich Wiesner 1
1 Materials Science and Engineering, Cornell University, Ithaca, New York, United States, 2 Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York, United States, 3 Physics, Cornell University, Ithaca, New York, United States
Show AbstractMulticompartment nanoparticle systems enable additional control over drug delivery by taking advantage of the geometrical or chemical distinction between each compartment. Mesoporous silica nanoparticles (MSNs) possess large accessible porosity coupled with flexible surface functionalization capabilities, thus providing a platform for well-controlled drug delivery. Here, we present a facile one-pot synthesis of MSNs with two distinct, well-ordered nanostructures whose pores are epitaxially connected. Tuning the initial mixture compositions allows precise control over relative fractions of different morphologies as characterized by transmission electron microscopy (TEM) and small angle x-ray scattering (SAXS). Chemical and/or geometrical differentiation of the two compartments for potential drug delivery applications is explored.
9:00 PM - JJ5.45
Folate Modified Silica Nanoparticles for Targeted Drug Delivery.
Fabiola Porta 1 , Nabila Bardine 2 , Gerda Lamers 3 , Antony Durston 2 , Jeffrey Zink 4 , Alexander Kros 1
1 Soft Condensed Matter, Leiden University, Leiden Netherlands, 2 Molecular Biology, Leiden University, Leiden Netherlands, 3 Institute of Biology, Leiden University, Leiden Netherlands, 4 Chemistry and biochemistry, UCLA, Los Angeles, California, United States
Show AbstractIn the burgeoning field of drug delivery, many innovative materials have been designed to create novel drug delivery systems, like liposomes, dendrimers and hydrogels. Several prerequisites have to be taken into consideration for the design of an advanced drug delivery system: the carrier has to release the correct amount of drug in a specifically targeted cell while protecting the payload from degradation via immune response and metabolism pathways. Mesoporous silica nanoparticles (MSN) could potentially fulfil all these requirements. Here we present a folic acid modified MSNs resulting in a targeted and stimuli responsive nanocarrier. Furthermore the folic acid moieties are integrated in a nanovalve system, which is activated by esterases. The MSNs have been loaded with fluorescein as a model compound, and the pores have been closed with a rotaxane structure bearing the folate at its terminus in order to prevent any premature release and to act as a targeting group towards cancer cells. The release of fluorescein has been tested in vitro and upon activation of the system with pig liver esterase; the payload has been released confirming the hypothesis that the guest molecule is effectively held by the nanocarrier and released only after activation. The cellular uptake of the MSNs in sarcoma cells, and the subsequent release of the drug camptothecin (CPT) has been evaluated with confocal laser scanning microscopy and Western Blot assays. In another example the in vivo toxicity of the silica based nanocarriers has been studied in Xenopus laevis (tropical frogs). For this purpose, PEG-coated MSNs have been loaded with retinoic acid (RA), a model compound whose effects are well known on the development of the frogs. We have evaluated the RA release efficiency and their toxicity, via in situ hybridization (ISH) studies of specific genes involved in the development of the frog which are affected by retinoic acid. This study shows that MSNs are biocompatible with living systems, which makes MSNs a versatile building block for a new generation of drug delivery systems.
9:00 PM - JJ5.46
Gold/Silver Coated Core@Shell Magnetic Nanomaterials: Fabrication, Characterization, and Biomedical Applications.
Lingyan Wang 1 , Jin Luo 1 , Shiyao Shan 1 , Elizabeth Crew 1 , Jun Yin 1 , Chuan-Jian Zhong 1
1 Department of Chemistry, State University of New York at Binghamton, Binghamton, New York, United States
Show AbstractThe design of functional nanomaterials is important for biomedical applications such as diagnostics, imaging, therapies, etc. One challenging area is the ability to create bio-functional nanoprobes for the detection of biological activities in bioassay or diagnostic methods. Gold/silver coated magnetic nanoparticles (M@Au or M@Ag) are two important classes of nanomaterials for addressing this challenge in view of the unique combination of the nanoscale magnetic core and the functional shell for a wide range of applications. This presentation highlights some of our recent findings in the investigation of the synthesis, characterization and application of these core@shell magnetic nanoparticles. Examples will focus on strategies for the synthesis of M@Au (M=Fe2O3, Fe3O4, or MnZn Ferrite, etc.) nanoparticles, characterizations of the core@shell nanostructures, and explorations of potential applications of the core@shell nanomaterials in terms of biological and interfacial reactivities such as the surface functionalization of M@Au by proteins and spectroscopic labels for use in surface enhanced Raman scattering (SERS) assays of protein binding and cutting on DNA assemblies. Implications of the findings to exploiting the spectroscopic properties of the core@shell magnetic nanoparticles in early detection of cancer will also be discussed.
9:00 PM - JJ5.47
Rapid Diagnosis of Escherichia Coli O157:H7 Using Carbon Nano Tube Field Effect Transistor (CNT-FET) Direct Binding Assay.
Sung-Jae Chung 1 , Man Kim 1 , Woo Jae Park 2 , Steingrimur Stefansson 1 , Saeyoung Ahn 1
1 , FTI, Rockville, Maryland, United States, 2 , Mclean High School, Mclean, Virginia, United States
Show AbstractELISA, and other methods based on the same principle, are sensitive and specific, but they suffer from several disadvantages, such as their inherent complexity and requirement for multiple reagents, incubation and washing steps and require a relatively large sample size. We have adapted a new Carbon NanoTube field effect transistors (CNT-FET) based platform to capture Escherichia coli antigens using only the capture anti- body showing good correlation with an established ELISA assay Contrived positive and negative specimens were used to test the new CNT-FET platform and results were obtained within three minutes per each sample. The test is easy to perform, rapid, and cost efficient making it a valuable screening tool for E. coli. In this study, we looked at the applicability of using CNT field effect transistor based biosensor as a rapid diagnostic platform for Escherichia coli O157:H7 The CNT-FETs platform detected positive E. coli samples in three minutes using only 2.5 μL of sample volume. This low sample volume required by the CNT-FET platform can be especially advantageous for diagnostic tests constricted by limited amount of samples. The negative result revealed background noise, but the two positive samples show that the platform is able to detect at various concentrations.
9:00 PM - JJ5.48
Plasmonic Biosensors with Composite Nanosilver Structures.
Georgios Sotiriou 1 , Christoph Blattmann 1 , Sotiris Pratsinis 1
1 Particle Technology Laboratory, ETH Zurich, Zurich Switzerland
Show AbstractSilver nanoparticles have the lowest plasmonic losses in the UV-visible spectrum and that makes them attractive for their application as biosensors and bioimaging agents [1]. Here composite nanosilver-silica structures are made by a scalable aerosol route [1,2] and are investigated for their suitability as plasmonic biosensors. The morphology and optical properties of these structures is characterized, while their plasmonic performance is investigated.References[1] Sotiriou, G. A., Sannomiya, T., Teleki, A., Krumeich, F., Vörös, J. & Pratsinis, S. E. Non-toxic dry-coated nanosilver for plasmonic biosensors. Adv. Funct. Mater. 20, 4250-4257 (2010).[3] Sotiriou, G. A., Hirt, A. M., Lozach, P. Y., Teleki, A., Krumeich, F. & Pratsinis, S. E. Hybrid, silica-coated, Janus-like plasmonic-magnetic nanoparticles. Chem. Mater. 23, 1985-1992 (2011).
9:00 PM - JJ5.49
SEM and STEM Imaging to Accurately Locate Nanoparticles within Biological Systems.
Paul Kempen 1 , Moritz Kircher 2 , Sanjiv Gambhir 3 , Robert Sinclair 1
1 Materials Engineering and Science, Stanford University, Stanford, California, United States, 2 Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York, United States, 3 Molecular Imaging Program in Radiology and Bioengineering, Stanford University, Stanford, California, United States
Show AbstractWith increased interest in nanotechnology as a novel approach to treat and diagnose cancer it is important to accurately locate and characterize the interactions of nanoparticles (NPs) within a biological environment. Because of the resolution required, electron microscopy is essential characterize nanoparticle interactions from the intra-tissue level down to the intra-cellular level. In this work, techniques were developed that utilize scanning electron microscopy (SEM) correlated to light microscopy (LM) as well as scanning transmission electron microscopy (STEM) to study nanoparticles in biological systems.We developed a SEM technique to accurately characterize the location of Au core NPs within entire tissue sections. This technique utilizes correlative microscopy to link LM images where biological features and functions can be readily identified using proper staining protocols with the high resolution of SEM. Samples are stained and imaged using light microscopy then imaged in the SEM. A combination of secondary electron (SE) images and backscattered electron (BSE) images are utilized to locate the NPs within the tissue. SE images provide topographical information while BSE images allow us to differentiate between the higher atomic number NPs and tissue. These images are then accurately linked to the light microscopy images showing the precise location of NPs within the tissue.A STEM technique was developed to study the intra-cellular location of the NPs. STEM provides the ability to analyze “large” volumes of tissue while still being able to indentify individual NPs efficiently. This is due to the high mass contrast from the gold. In this technique small tissue samples, ~1mm3, are prepared using standard protocols, sectioned into ultrathin, 150nm, sections, and imaged in the STEM. Samples are analyzed at high scan rates to cover “large” volumes of tissue, >10000µm3. With this technique we are able to accurately identify the intra-cellular location of NPs.A section of brain tissue from a mouse injected with Au core NPs was prepared and stained using anti-olig2 immunohistochemistry to locate the tumor within the tissue. After LM imaging the section was imaged in the SEM and NPs were located using BSE imaging. Correlating the SEM images with the LM images indicated the NPs were located in the tumor and not the healthy tissue. A small sample of tumor tissue was also taken to perform STEM analysis. 57500µm3 of tumor tissue was analyzed with 923 NPs found, largely as clusters inside vesicles in the cell. This corresponds to a concentration of ~1.6X1010NPs/cm3. The combination of SEM with LM and STEM analysis allows a more complete understanding of the location and distribution of NPs within a tissue sample.This research is supported by the Center for Cancer Nanotechnology Excellence and Translation (CCNE-T) grant funded by NCI-NIH to Stanford University U54CA151459 Gambhir.
9:00 PM - JJ5.51
Carbon Nanotube Based Multifunctional Endoscopes for Single Cell Analysis and Microfluidic Separation.
Riju Singhal 1 , Zulfiya Orynbayeva 2 , Jun Jie Niu 3 , Michael Schrlau 1 , Vadym Mochalin 1 , Gary Friedman 4 , Yury Gogotsi 1
1 Materials Science and Engineernig, Drexel University, Philadelphia, Pennsylvania, United States, 2 Surgery Department, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States, 3 Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States, 4 Electrical and Computer Engineering, Drexel University, Philadelphia, Pennsylvania, United States
Show AbstractSingle cell studies have gained increased attention in recent years in order to understand cellular functioning in complex processes (like cell division during embryonic development), and owing to realization that heterogeneity exists amongst population of a single cell type (for instance certain individual cancer cells being immune to chemotherapy). Therefore devices enabling powerful analytical techniques like electrochemical detection, spectroscopy, optical detection, and separation techniques along with cell piercing and fluid transfer capabilities at the cellular level are desired. Glass micro-pipettes have conventionally been used for single cell operations, however their poor material properties and intrusive conical geometry have led to limited precision and scope for successful experimentation, resulting in increased research efforts to develop novel, non-intrusive cell probes. Carbon nanotubes (CNTs) are known for their superior physical properties and tunable chemical structure and possess a high aspect ratio, minimally invasive tubular geometry. Moreover, significant accomplishments have been made by researchers on chemical functionalization of CNTs, making realistic the idea of multi-functionality of resulting probe tips.Here we report a novel fluidic device fabricated by isolating and assembling a “single” CNT at the tip of a glass micro-pipette using a fluid flow based technique. The nanotube-glass junction was sealed with epoxy to allow fluid flow from the glass pipette into the nanotube, thereby enabling continuous fluid handling capability into cells. The nanotube was functionalized with paramagnetic iron oxide and gold nanoparticles facilitating simultaneous remote magnetic manipulation of the tip and surface enhanced Raman spectroscopy. Further, the glass pipette interior was coated with carbon facilitating electrophysiology. These probes were demonstrated to induce significantly less calcium response during cell piercing compared to glass pipettes. Thus, minimally intrusive "multifunctional cellular endoscopes” were developed (reported in Nature Nanotechnology 6, 57–64 (2011)).Meanwhile, we demonstrated an individual CNT to function as a nano-separation column for separating attoliter volumes of mixtures of different analytes (smallest volumes ever analyzed!). In this regard we demonstrated separation of two fluorescent dyes of significantly different molecular weights by flow through a 200 nm amorphous nanotube stuffed with smaller 20-30 nm multiwalled CNTs as stationary phase. Moreover we performed the process of liquid-liquid extraction using a 200 nm amorphous CNT by selectively extracting a fluorescent dye from a dye mixture using a solvent having different solubility for the two dyes. These nanotubes can then be used as aforementioned "endoscope" tips to perform separation processes on single cells.
9:00 PM - JJ5.52
Fabraction of Chitosan Microspheres Containing Anionic Proteins by Electrospinning.
Eunju Jo 1 , Ji Suk Choi 1 , Hye Sung Kim 1 , Young Ju Son 1 , Sujin Yoon 1 , Younghee Kim 1 , Hyuk Sang Yoo 1
1 Biomaterials Engineering, Kangwon National University, Chuncheon Korea (the Republic of)
Show AbstractChitosan is widely employed as a drug delivery system due to its superior biocompatibility and nontoxicity. In the current study, chitosan microsphere was prepared by electrospun chitosan solution at high voltages, which was followed by an instant solidification in sodium carbonate solutions. Chitosan solutions were ejected through 25G needles and a positive voltage of 2.5-10kV was applied for electrospinning. The fabricated microsphere was characterized by optical microscopy and scanning electron microscopy (SEM). Flow rates and viscosity of chitosan solutions significantly affected the size and the morphology of the chitosan microspheres. Average diameters of chitosan microspheres were significantly decreased in proportion to applied voltage and viscosity of chitosan solution. Fluorescently-labeled bovine serum albumin (BSA, pK=4.8) was encapsulated in the chitosan microsphere by electrospinning a mixture of chitosan and BSA solutions. The amount of BSA released from the microsphere was fluorescently determined. The electrospun microsphere showed high loading efficiency of BSA because of electrostatic force between cationic chitosan and anionic and immediate solidification of the chitosan microspheres. Therefore, electrospinning can be an alternative fabrication method of microspheres in aims to minimize protein denaturation as well as simplify preparation steps.
9:00 PM - JJ5.53
The Study of Normal and Cancer Cells by Scanning Force Modulation Microscopy.
Chungchueh Chang 1 , Marcia Simon 2 , Miriam Rafailovich 1
1 Materials Science and Engineering, SUNY at Stony Brook, Stony Brook, New York, United States, 2 Oral Biology and Pathology, SUNY at Stony Brook, Stony Brook, New York, United States
Show AbstractThe cytoskeleton of cells is the structural framework that predominantly shapes a cell and provides its mechanical rigidity. It not only provides mechanical rigidity, but also fulfills many important cellular functions. All of the tasks performed by cytoskeletal elements are finely tuned, regulated, and synchronized with the overall function of a specific cell. In other words, changes to cellular function during differentiation or due to disease are reflected in the cytoskeleton [1]. Therefore, cell rigidity should be able to distinguish cancer cells from normal cells. To investigate this, Scanning Modulation Force Microscopy (SMFM) was employed to measure the moduli of three different normal and transformed cell types. The results show that the moduli of normal keratinocytes, fibroblasts and osteoblasts are 2, 15, and 3 times harder than transformed keratinocytes, fibroblasts and osteoblasts, respectively. The extracellular matrices (ECM) were also measured by SMFM and in contrast to the findings with cells, the moduli of the ECM from normal keratinocytes, fibroblasts, and osteoblasts are 6, 2, and 4 times softer than the moduli of ECM from transformed keratinocytes, fibroblasts and osteoblasts, respectively. Taken together, the results suggest that SMFM can be used to detect the cancer cells amongst normal cells.This research was supported in part by the NSF-MRSEC program. [1] Guck, J. et al. Biophysical Journal 88:3689-3698, 2005
9:00 PM - JJ5.54
Microemulsion Synthesis of Fe/Fe3O4@SiO2–NH2 Magnetic Nanoparticles and Studying of Their Physicochemical Properties and Stability.
Katsiaryna Kekalo 1 , Ian Baker 1 , Katherine Koo 1 , Evan Zeitchick 1
1 , Dartmouth college, Hanover, New Hampshire, United States
Show AbstractFe/Fe3O4 core/shell magnetic nanoparticles (MNP) coated with SiO2 and with NH2 groups attached are being developed since they are able to transform alternating magnetic field energy into heat, a feature useful for localized hyperthermia treatment of tumors. The small size of the nanoparticles (12-22 nm) allows them to be taken up by cells and, upon application of external magnetic field, cause damage to the cells by heating to 42-45 °C. Fe3O4 and Fe2O3 are most commonly used for this purpose [1]. However, a Fe core can provide more effective hyperthermia treatment because Fe has more than twice the saturation magnetization of Fe3O4 or Fe2O3 – 218, 92 and 80 emu/g, respectively.Iron MNPs were synthesized in inert atmosphere via the reaction between FeCl3 and NaBH4 in microemulsion droplets of water in octane using cetyl trimethylammonium bromide and butanol as surfactants. A thin Fe3O4 layer was produced on the iron MNPs using slow controlled oxidation at room temperature. A silica shell was deposited on the Fe3O4 using 3-aminopropyltrimethoxysilane following the method of Zhang et al. [2, 3]. The resulting MNPs were studied using VSM, XRD, FTIR, TEM, colorimetry. The diameter of the Fe core was typically 8-16 nm, while the thickness of the Fe3O4 shell was 2-3 nm. The presence of the silica layer was confirmed using FTIR spectra and the number of NH2-groups on each MNP was determined based on colorimetric tests using ortho-phthalaldehyde.It was shown that Fe/Fe3O4 core/shell MNPs retain their magnetic and physicochemical properties for long periods if they are stored in vacuum and even in air. However, water and, especially a saline solution, causes rapid oxidation and a corresponding degradation in magnetic properties. The thickness of the Fe3O4 shell plays a significant role on the stability of Fe/Fe3O4 MNP on air: too thin oxide layer can not prevent the MNPs from burning in air and/or during mechanical crushing of aggregates. The silica coating further increases the stability of the Fe/Fe3O4 MNP and the presence of the NH2- groups allows functionalization of the MNPs with polysaccharides or proteins.The research was supported by NIH grant 1U54CA151662-01.1. R. Hergt et al. / J Phys Condens Matter 18 (38) (2006), pp. S2919–S29342. Zeng et al. / Appl. Phys. Lett. 90, (2007) 2331123. G. Zhang et al. / Mat. Sci. and Eng. C 30 (2010) 92–97
9:00 PM - JJ5.55
Theragnostic Nanocarrier Prepared with Tri-Fuctional Enzymes.
Hee-su Kwon 1 , Sung-Geun Jung 1 , Young-Rok Kim 1
1 Graduate school of biotechnology, Kyung Hee university, Yong-In, Kyung gi-do, Korea (the Republic of)
Show AbstractThe monoclonal antibody of A33 (mAb 33) detects a membrane antigen that is expressed in normal human colonic and small bowel epithelium and >95% of human colon cancers. Although mAb 33 has the good benefit for detecting the A33 positive cancer cell lines, it can be easily disappeared in the body. This limitation was overcome by using small antigen binding site of mAb 33 as single chain variable fragment (A33 scFv) without reducing the binding ability. Moreover, we can attach the variable functional groups with A33scFv using by genetic engineering. These days, there are many studies related with the conjugation of functional groups with A33scFv for ability of cancer treatment. Among them, A33scFv, with cytosine deaminase, which can converts 5-fluorocytosine (5-FC) into 5-fluorouracil (5-FU) as a cancer chemotherapy agent. This approach had good success in their specific application but this system can’t be traced in vivo because it doesn’t have any fluorescence. Herein, we have constructed the A33scFv with GFP and PHA synthase. This tri-fusion enzyme was expressed with E. coli Rosetta gami and this enzyme can be fluorescent and make the polyhydroxyalkanoate (PHA) particles as a cancer chemotherapy drug carrier in simple based on enzymatic biosynthesis. The unique activities of tri-fusion enzyme were verified by using fluorescence microscopy and Ellman’s assay and the specificity for A33 antigen were confirmed by using SW1222 (A33+) and HT29 (A33-) colon cancer cell lines in vitro. This new approach will provide wide applications in effective diagnosis and specific delivery of functional compounds to the cancer cells.
9:00 PM - JJ5.6
Potential of Polyion Complex Nanoparticle Composed of Mercaptoundecahydrododecaborane-Appended High Molecular Weight Polyamine as a Boron Carrier for Neutron Capture Therapy.
Takeshi Nagasaki 1 , Masayuki Umano 1 , Hironobu Yanagie 2 , Mitsunori Kirihata 3 , Shin-ichiro Masunaga 4 , Koji Ono 4
1 Department of Applied Chemistry and Bioengineering, Osaka City University, Osaka, Osaka, Japan, 2 Department of Nuclear Engineering and Management, The University of Tokyo, Tokyo, Tokyo, Japan, 3 Department of Bioscience and Informatics, Osaka Prefecture University, Sakai, Osaka, Japan, 4 Reserch Reactor Institute, Kyoto University, Kumatori, Osaka, Japan
Show Abstract Recently, boron neutron capture therapy (BNCT) attracts attention as a cancer therapy of the low side effect. It is important to deliver 10B atoms only into the carcinoma cell selectively for the improvement of the treatment efficiency. A few low-molecular-weight boron compounds such as sodium mercaptoundecahydrododecaborane (BSH) and the boronophenylalanine (BPA) are clinically used as 10B carrier. However, they have some disadvantages such as low water solubility and low accumulation into tumor tissue. ε-Poly-L-lysine (ε-PLL) is a naturally occurring polyamine characterized by the peptide linkages between the carboxyl and ε-amino groups of L-lysine. Because of high safety ε-PLL is applied practically as a food additive due to its strong antimicrobial activity. Herein, we have investigated a polyion complex nanoparticle composed of mercaptoundecahydrododecaborane-appended high molecular weight polyamine as a BNCT drug. Since this polymeric boron carrier has anionic zeta-potential, polyion complex with cationic polymer afford nanoparticles suitable for safe and effective delivery into tumor tissues based on Enhanced Permeability and Retention (EPR) effect. The neutron irradiation experiment by using the polymeric 10B carrier showed suppression effect for the tumor growth in vivo. In vivo biodistribution was estimated with the BPP/polyamine complex by using colon 26-bearing mice. Electrostatic interaction-mediated nanoparticle showed rapid clearance from the blood stream and nonspecific accumulation in the liver, spleen, and kidneys. While the boron concentration in tissues other than kidneys decreased along with the disappearance of boron in the blood due to renal clearance, the boron concentration in tumor gradually increased till 12 h after injection. Although the boron concentration in tumor is still lower than that in liver and kidney, it reached to about 8 ppm B. BNCT for tumor-bearing mice using the BPP/polyamine complex was carried out with 26-bearing mice at left thigh (16-18 g; 56 per group). The BPP/polyamine complex solution was injected via tail vein at a dose of 4.0 mg 10B/kg (400 ppm of 10B concentration; 200 μL). Twelve hours after iv injection, the mice were irradiated in KUR atomic reactor for 120 min at a rate of 5 x 1012 neutrons/cm2. Tumor growth in mice treated with the BPP/polyamine complex was significantly suppressed after neutron irradiation. In summary, in order to develop the selective and effective boron delivery for tumor tissue, we applied the boron cluster-bearing biodegradable polyamine. This polymeric boron carrier is promising boron delivery system for BNCT.
9:00 PM - JJ5.7
Superparamagnetic Iron Oxide Nanoparticles in Tumor Diagnostics.
Aruna Sigdel 1 , Lan Yao 2 , Yana Reshetnyak 2 , Shouheng Sun 1
1 Chemistry, Brown University, Providence, Rhode Island, United States, 2 Physics, University of Rhode Island, Kingston, Rhode Island, United States
Show AbstractSuperparamagnetic iron oxide nanoparticles are FDA approved as contrast agents. These nanoparticles will increase the contrast if localized in tumors. One hallmark of tumor that can be utilized to target is using its hypoxic and acidic character making their extracellular pH very low (pH 5.5-6.5). pH low insertion peptide (pHLIP) has three states; at physiological pH it is soluble in water or it is bound to the surface of a membrane however at low pH, this peptide forms a helix and inserts into the cell membrane. Studies have shown that, pHLIP can target different types of tumors in vitro and in vivo; however kidney toxicity is significant. We have used superparamagnetic iron oxide nanoparticles (SPIOs) as a delivery agent and a contrast agent and conjugated with pHLIP. Studies were performed to see tumor targeting in vitro and in vivo for diagnostic imaging and kidney toxicity. These SPIOs-pHLIP constructs can be utilized to diagnose all kinds of tumors.
9:00 PM - JJ5.8
Gold Nanoparticle Tags for SERS-Based Imaging of Human Glioblastoma Cells.
Laura Fabris 1 , Prabhas Moghe 2 , Bryan Paladini 1 , Dominik Naczynski 2
1 Materials Science and Engineering, Rutgers University, Piscataway, New Jersey, United States, 2 BIomedical Engineering, Rutgers University, Piscataway, New Jersey, United States
Show AbstractEarly cancer detection is of fundamental importance to reduce morbidity and recurrence, especially for highly invasive cancers such as human glioblastoma. A great potential has been recognized for the use of nanoparticle (NP)-based imaging agents, capable of specifically visualizing only the targeted diseased cell. The possibility of achieving early detection at the single cell level could enable the visualization of tumor margins and the analysis of post-surgical histological samples with fast detection times and high sensitivity. The additional advantage of NP-based systems is the ease of implementation to also carry therapeutic moieties, thus generating novel theranostic tools. Surface enhanced Raman spectroscopy (SERS)-based imaging tags are starting to attract increasing attention due to their increased brightness and the possibility of multiplexing. In this contribution I will report on the development of SERS-based imaging tags, composed of gold NP dimers held together by a Raman active small molecular linker. These systems are capable of specifically targeting and detecting in vitro U87 human glioblastoma cells, where the presence of a SERS peak pattern typical of the small molecular linker ris indicative of the uptake of the NPs by the cells. In our experiments, thiolated PEG was used to stabilize the NP systems, avoiding coalescence and improving biocompatibility, while increasing shelf life. In addition, thiolated FITC-PEG was bound to the surface of the NP dimers to prove, via confocal microscopy, the results achieved via SERS. The combined use of cyclic RGD peptides to target αvβ3 integrins overexpressed on the surface of cancerous cells, and of Tat peptides, belonging to the family of cell penetrating peptides, ensured an efficient targeting and binding of the SERS tags to the surface of the cells or their penetration into the cytoplasm. Combined analysis carried out via confocal and Raman microscopy demonstrated the efficient tagging and imaging of U87 cells via SERS-based Au NP dimers-based tags. Current studies are now targeting melanoma cells, to demonstrate the versatility of our systems and set the ground for versatile, SERS-based tagging systems relevant to a wide range of biomedical applications.
Symposium Organizers
Piotr Grodzinski National Cancer Institute
Scott Manalis Massachusetts Institute of Technology
Sonke Svenson Cerulean Pharma Inc.
Xing-Jie Liang National Center for Nanoscience and Technology of China
Wenbin Lin University of North Carolina-Chapel Hill
JJ6: Nucleic Acids in Detection and Drug Delivery
Session Chairs
Wednesday AM, November 30, 2011
Room 203 (Hynes)
9:30 AM - **JJ6.1
Systemic Delivery of siRNA to Solid Tumors via Targeted Nanoparticles: Preclinical to Clinical.
Mark Davis 1
1 Chemical Engineering, California Institute of Technology, Pasadena, California, United States
Show AbstractOne of the major challenges in the development of siRNA-based therapeutics for human use is their effective, systemic delivery. We have been investigating the potential of targeted nanoparticles for the systemic delivery of siRNA in cancer, and have reported that transferrin targeted nanoparticles formulated with a cyclodextrin-containing polycation and anti-EWS-FLI1 siRNA can be effective anti-tumor agents in a mouse model of Ewing’s Sarcoma [1]. Targeted nanoparticles show behaviors that provide advantages in the systemic delivery of siRNA. For example, they can protect and deliver non-chemically modified siRNA, they can deliver a large “packet” of siRNA, they can have tunable binding affinities to target cell surfaces and when correctly assembled can systemically deliver siRNA without immune stimulation. Nanoparticles in the size range of 50-100 nm can circulate and localize in tumors [1,2]. These particles can carry a large amount of siRNA as the polycation protects the RNA from degradation and transports it into cells where the kinetics of gene inhibition are a strong function of the cell doubling time [3]. Using a combination of PET and bioluminescent imaging, the biodistribution of the nanoparticles is shown to not be a strong function of the presence of the targeting ligand, while the uptake and function in tumor cells are critically dependent on the function of the targeting ligand [4]. We have confirmed this behavior with other targeted nanoparticles [5]. Repetitive dosing in monkeys with the cyclodextrin-containing polycation nanoparticles can be safely accomplished without eliciting complement activation or interferon and other immunostimulatory processes [6]. This delivery system entered a Phase I clinical trial in 2008 [7], and results from the clinical trial [8,9] and how they compare to results from animal studies will be discussed. More recently, we have extended this delivery system to include antibody and antibody fragment targeting agents. The combination of a therapeutic antibody targeting agent and a therapeutic siRNA can provide a dual functioning nanoparticle (results from animal models will be presented). [1] Hu-Lieskovan S et al., Cancer Res., 65 (2005) 8984-8992. [2] Pun SH et al., Cancer Biology & Therapy, 3 (2004) 641-650. [3] Bartlett DW and Davis ME, Nucleic Acids Res., 34 (2006) 322-333.[4] Bartlett DW et al., PNAS, 104 (2007) 15549-15554. [5] Choi, CHJ et al., PNAS, 107 (2010) 1235-1240.[6] Heidel JD et al., PNAS, 104 (2007) 5715-5721.[7] Davis, ME, Mol. Pharm., 6 (2009) 659-668.[8] Davis, ME et al., Nature, 464 (2010) 1067- 1070.[9] Ribas, A et al, ASCO Abstract No. 3022 (2010).
10:00 AM - JJ6.2
Structure and Properties of DNA Functionalized on the Surface.
Yaroslava Yingling 1 , Abhishek Singh 1
1 Materials Science and Engineering, North Carolina State University, Raleigh , North Carolina, United States
Show AbstractThe genetic alterations in cancer cells are determined by sequence of DNA which is expressed on DNA micro arrays. DNA-arrays can be modeled as surfaces functionalized with ssDNAs that can uniquely and reversibly bind complimentary DNAs. Such DNA modified materials can also be used in drug delivery devices, nanoscale supramolecular assembly, as bio, optical, electrochemical and piezoelectricbiosensors. The process of DNA hybridization controls the properties and assembly efficiency of DNA functionalized system. However, experimental observation show that a large fraction of surface bound DNA is unavailable for hybridization. We conducted molecular dynamics simulation studies of DNA strands thiolated on the surface and in the presence of duplex and compared their dynamics to the dynamics of the DNA strands in solution. We investigated the optimal ssDNA length, effect of linker type and length to understand the effect of immobilization on subsequent DNA hybridization. Our results indicate that sensitivity and selectivity are directly dependent on the length and sequence of ssDNA strands. The persistence length, folding pathway and time are directly dependent onthe hybridization and length of ssDNA. Minimum energy pathways were explored to understand the kinetics of ssDNA folding during the event of hybridization. Simulations suggest that restrained ssDNAs, compared to labile suspensions of free ssDNAs, are more capable of hybridization and hence DNA-based assembly. Our study helps understanding the science associated with the ssDNA hybridization and provides feedback to the associated experiments
10:15 AM - JJ6.3
Polyvalent DNA-Functionalized Gold Nanoparticles as Selective Agents for MicroRNA Detection and Regulation.
Ali Alhasan 1 2 , Andrew Prigodich 1 2 , Pinal Patel 1 2 , Liangliang Hao 1 2 , Weston Daniel 3 2 , C. Shad Thaxton 4 5 6 , Chad Mirkin 3 2
1 Interdepartmental Biological Sciences Program, Northwestern University, Evanston, Illinois, United States, 2 International Institute for Nanotechnology, Northwestern University, Evanston, Illinois, United States, 3 Department of Chemistry, Northwestern University, Evanston, Illinois, United States, 4 Department of Urology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States, 5 Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, United States, 6 Institute for BioNanotechnology and Medicine, Northwestern University, Chicago, Illinois, United States
Show AbstractGold nanoparticles densely surface-functionalized with oligonucleotides (DNA-Au NPs) are hybrid materials with novel bioactivities. DNA-Au NPs have unique physicochemical properties that enable them to address many challenges associated with molecular biodetection and intracellular gene regulation. We have demonstrated that polyvalent DNA-functionalized gold nanoparticles (DNA-Au NPs) selectively enhance RNase H activity while inhibiting general nucleases that are normally present in serum. We have investigated the nanomaterial characteristics to uncover the mechanism of selective RNase H activation and found that the high DNA density of DNA-Au NPs is responsible for this unusual behavior. This combination of properties is particularly interesting in the context of gene regulation in cancer, since high RNase H activity results in rapid microRNA (miRNA) degradation and general nuclease inhibition results in high biological stability of the DNA AuNP conjugates. These nanoconjugates were applied successfully to regulate the expression level of miRNAs, which has been quantitatively demonstrated by utilizing DNA-Au NPs to develop a novel scanometric-based miRNA profiling technology. This work adds to our understanding of polyvalent DNA-Au NPs as agents for miRNA detection and target gene regulation.
10:30 AM - JJ6.4
DNA Denaturation in the Presence of Gold Nanoparticles with Cationic Ligands.
Justin Railsback 1 , Abhishek Singh 1 , Ryan Pearce 1 , Timothy McKnight 2 , Yaroslava Yingling 1 , Anatoli Melechko 1
1 Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina, United States, 2 Engineering Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge , Tennessee, United States
Show AbstractNanoparticle vectors for gene delivery have been a subject of intense research as potentially safer alternative to viral vectors for gene therapy. A method for packaging genomic DNA for cellular uptake is to nonspecifically bind many nanoparticles to a DNA strand via an electrostatic interaction between the negative charges on the DNA backbone and positively charged ligands on a nanoparticle surface.This creates a complex that has been shown to facilitate cellular uptake. We demonstrate that strong interaction of cationic nanoparticles with DNA can also lead to DNA denaturation instead of complex formation. The gold nanoparticles (AuNPs) in our study were 1.4 nm in diameter and had mixed monolayer shells containing both inert hydrocarbons and about 6 aminated ligands per particle. A 2kbp linear double stranded DNA plasmid encoding for yellow fluorescent protein was incubated in phosphate buffer saline containing AuNPs and was found to either denature or form a complex depending on the AuNP to DNA molar ratio. Denaturing and complex formation were studied by gel electrophoresis, and fluorescence quenching measurements were used to indicate AuNP-DNA binding. Atomistic molecular dynamics (MD) simulations were employed to elucidate potential mechanisms of denaturing. MD simulations show that single NP binding can induce helical distortion, however, oligomer denaturation due to a single particle is unlikely. The process of denaturation depends on both the dynamics of charged and inert ligands, as well as the concentration of particles. Several particles must act in concert to denature DNA: charged ligands interact with the DNA backbone, straining the helix while the hydrophobic hydrocarbon ligands intercalate through the DNA strands and disrupt base pairing.
10:45 AM - JJ6.5
Detection of DNA Methylation Using Nanoparticles.
Albena Ivanisevic 1
1 , NCSU, Raleigh, North Carolina, United States
Show AbstractDetecting methylated DNA has become of recent interest for multiple topics in epigenetics, DNA replication and repair, genomic imprinting, x-chromosome inactivation, gene regulation, and in cancer diagnostics. We present a facile, simple method to detect DNA methylation by measuring the transverse proton relaxation behavior. Positively charged nanoparticles (NPs) are arranged along the negatively charged backbone of DNA strands through electrostatic interactions. The arrangement of NPs along DNA strands aids to amplify and compare the transverse proton relaxation signal for un-cut versus cut DNA strands cleaved by sequence specific restriction enzymes. Results from our work suggest that the presence of methylation on DNA can be detected using superparamagnetic NPs using NMR.
11:30 AM - **JJ6.6
Shape and Size Specific Nanoparticle Cancer Therapies.
Kevin Herlihy 1 , Mary Napier 1 , Joseph DeSimone 1 2 3
1 Lineberger Comprehensive Cancer Center, UNC Chapel Hill, Chapel Hill, North Carolina, United States, 2 Chemistry, University of North Carolina, Chapel Hill, North Carolina, United States, 3 Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, United States
Show AbstractNanoparticle (NP) drug delivery systems can preferentially deliver and release a therapeutic cargo in the optimal dosage range at the site of disease, which in turn has the potential to result in improved therapeutic efficacy, reduced side effects and improved patient compliance. In fact, some of these improvements have already been realized in first generation nanotechnology-based therapeutics, including Doxil and Abraxane. Current research is now focused on engineering the next generation of nanoparticle therapeutics. Challenges in successful design are the numerous biological barriers that impede efficacious and efficient delivery of drugs to the site of the disease upon systemic administration. A thorough understanding of the impact of the physical parameters of the particles—size, shape, surface characteristics and deformability—on biodistribution will aid in the rational design of nanoparticle therapeutics. Using a top-down nanofabrication process known as Particle Replication In Non-wetting Templates (PRINT®), we have demonstrated control of particle size and surface chemistry. Due to the unique nature of this nanofabrication process, we can also tailor particle shape, modulus and composition of these particles independently. Using this process, we have fabricated PEG hydrogel particles in a variety of shapes and sizes in order to elucidate the effect of these parameters on biodistribution and tumor uptake. A silyl ether camptothecin prodrug was then added to the particle matrix for pH-sensitive release in low pH environments such as tumor interstitium. We were able to use the same templates to form identically shaped particles that were composed of poly(lactic-co-glycolic acid) loaded with lipophilic drugs such as docetaxel. Using multiple nanoparticle platforms with the same size and shape, we are focused on elucidating the differences in nanoparticle biodistribution and drug pharmacokinetics.
12:00 PM - JJ6.7
Transport of Polar Oligonucleotide Cargos into Tumor Cells by Amphiphilic ``Striped'' Cell-Penetrating Nanoparticles.
Prabhani Atukorale 1 , Randy Carney 2 , Jin-Mi Jung 1 , Christopher Jewell 1 , Francesco Stellacci 2 , Darrell Irvine 1 3
1 Mat. Sci. & Eng./Biological Eng., MIT, Cambridge, Massachusetts, United States, 2 Mat. Sci. & Eng., EPFL, Lausanne Switzerland, 3 , Howard Hughes Medical Inst., Chevy Chase, Maryland, United States
Show AbstractGold nanoparticles (AuNPs) have recently become of great interest in drug delivery and tumor therapy because these materials can be functionalized with a wide range of biological cargos with minimal toxicity, and can be efficiently cleared from the body. Highly ordered self-assembled monolayers can be assembled on the surface of small gold particles, and mixtures of hydrophobic and hydrophilic organic ligands packed on the surfaces of AuNPs via chemisorption can self-organize to arrange into nanoscale ordered “striped” surface morphologies. We recently reported the unexpected finding that highly water-soluble striped NPs bearing a mixture of sulfonate- and methyl-terminated ligands are capable of penetrating the plasma membrane of cells, in contrast to AuNPs bearing the same hydrophilic/hydrophobic ligands in a disordered arrangement, which are taken up by endocytosis. To determine whether striped NPs would retain their cell entry properties when conjugated to large polar drug cargos, the cellular uptake of striped NPs (and non-striped control particles) conjugated with thiol-terminated RNA and DNA oligonucleotides was assessed. Strikingly, striped AuNPs conjugated to both single-stranded and double-stranded oligonucleotides were taken up by both tumor cells (melanoma cells) and normal cells in vitro, even under conditions where active uptake processes were blocked by incubation at 4 deg. C or through the use of pharmacological inhibitors. Control sulfonate-capped particles lacking the striped domains failed to promote oligo uptake when active endocytic processes were blocked in cells, and were taken up at 50% lower levels at 37 deg. compared to striped particles. Confocal microscopy confirmed a cystosolic localization of particle-conjugated oligonucleotides carried into cells by striped AuNPs. Total oligo uptake was inversely related to oligo length for single-stranded oligos attached to the striped particles. These data suggest that striped AuNPs may be of interest for intracellular delivery of membrane-impermeable drug cargos in tumors such as siRNA, and ongoing studies are exploring the potential of these materials for modulating function in live tumor cells.
12:15 PM - JJ6.8
Multiplexed Magnetic Labeling Amplification Using Oligonucleotide Hybridization.
Monty Liong 1 , Carlos Tassa 1 , Stanley Shaw 1 , Hakho Lee 1 , Ralph Weissleder 1
1 Center for Systems Biology, Massachusetts General Hospital, Boston, Massachusetts, United States
Show AbstractThe next generation of biocompatible magnetic materials is expected to afford significant advances in cell separation, diagnosis and therapy in scant cell populations. The amplification of signals from small number of cells, however, has proven challenging due to difficulties in developing efficient methods for tagging multiple probes onto available receptors on human cells. We describe a highly sensitive and multiplexable magnetic tagging method that significantly amplifies the loading of magnetic nanoprobes (MNPs) onto targeted cells. The method utilizes linker oligonucleotide strands as the binding agents between the oligonucleotide-functionalized monoclonal antibodies and the oligonucleotide-modified MNPs (MNP-DNA). We subsequently validated this method by a) taking surface plasmon resonance measurements, b) labeling specific growth factor receptors, and c) detecting human cancer cells. We found that the multi-step labeling method is far more effective than labeling using direct MNP-antibody immunoconjugates. To further amplify the magnetization signal intensity, and therefore enhance the detection sensitivity or capture efficiency, we labeled cells with multiple rounds of complementary MNP-DNA probes. A set of labeling experiments, which combined multiplexed analysis and signal amplification, were also designed to take advantage of the hybridization specificity between oligonucleotide strands. We eventually demonstrated the efficiency of this method by simultaneously targeting three cancer markers of interest (HER2/neu, EpCAM, and EGFR), each of which exhibit varying abundance levels, on a panel of cancer cell lines. Not only did this method allow multiplexed analysis, but it was also capable of detecting multiple markers in a single sample containing only a small number of cells.
12:30 PM - JJ6.9
Single Molecule Detection of Nitric Oxide Enabled by d(AT)15 DNA Adsorbed to near Infrared Fluorescent Single-WalledCarbon Nanotubes.
Jingqing Zhang 1 , Ardemis Boghossian 1 , Paul Barone 1 , Alina Rwei 1 , Jong-Ho Kim 1 , Dahua Lin 2 , Daniel Heller 1 , Andrew Hilmer 1 , Nitish Nair 1 , Nigel Reuel 1 , Michael Strano 1
1 Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States, 2 Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
Show AbstractWe report the selective detection of single nitric oxide (NO) molecules using a specific DNA sequence of d(AT)15 oligonucleotides, adsorbed to an array of near-infrared fluorescent semiconducting single-walled carbon nanotubes (AT15-SWNT). While SWNT suspended with eight other variant DNA sequences show fluorescence quenching or enhancement from analytes such as dopamine, NADH, L-ascorbic acid, and riboflavin, d(AT)15 imparts SWNT with a distinct electivity toward NO. In contrast, the electrostatically neutral polyvinyl alcohol enables no response to nitric oxide, but exhibits fluorescent enhancement to other molecules in the tested library. For AT15-SWNT, a stepwise fluorescence decrease is observed when the nanotubes are exposed to NO, reporting the dynamics of single-molecule NO adsorption via SWNT exciton quenching. We describe these quenching traces using a birth-and-death Markov model, and the maximum likelihood estimator of adsorption and desorption rates of NO is derived. Applying the method to simulated traces indicates that the resulting error in the estimated rate constants is less than 5% under our experimental conditions, allowing for calibration using a series of NO concentrations. As expected, the adsorption rate is found to be linearly proportional to NO concentration, and the intrinsic single-site NO adsorption rate constant is 0.001 s-1 μM NO-1. The ability to detect nitric oxide quantitatively at the single-molecule level may find applications in new cellular assays for the studyof nitric oxide carcinogenesis and chemical signaling, as well as medical diagnostics for inflammation.
12:45 PM - JJ6.10
Magnetically Double Emulsion Nanocapsules for Remotely Controlled DNA Release and Cancer Cell Targeting.
Shang-Hsiu Hu 1
1 Dept. of Materials Sciences and Engineering, National Chiao Tung University, Hsinchu, Taiwan Taiwan
Show Abstract Engineered magnetically double emulsion nanocapsules capable of integrating hydrophilic and hydrophobic substances into a compact particle with high encapsulated efficiency using an amphiphilic copolymer is demonstrated. Here, we propose that novel nanoscale water-in-oil-in-water (WOW) double emulsion capsules possessing large volumes of single uniform reservoirs where plasmid DNA can be embedded efficiently in ultra-thin polymer-physical shell to eliminate undesirable release before reaching the target sites appears to be practically desired. The magnetic nanoparticles incorporated in the double emulsion capsules are employer as a functional phase which allow the response of the resulting DNA carriers to be activated more dynamically and efficiently, aimed to achieve a real-time response to an immediate environmental change, i.e., magnetic field. High-frequency magnetic field (HFMF) triggers a pulsatile release of plasmid DNA to be achieved on a real-time responsive base without undesirable delay in dosing accuracy under administration. This approach differs from traditional double emulsions where the carriers can reach the nanosizes and display the significantly tunable water reservoirs for biomedical and clinic needs, and encapsulate most kinds of therapeutic molecules or nanoparticles without any surface modification. Double emulsion nanocapsules also can be applied to fabricate other specific carriers by combing other functional materials or biomolecules also gave the stable nanoemulsions. Furthermore, use of WOW double emulsion-templated carriers overcomes key limitations of individual components together without interfering or sacrificing their original optical and active properties.
JJ7: Bio-Nano-Materials for Cancer II
Session Chairs
Wednesday PM, November 30, 2011
Room 203 (Hynes)
2:30 PM - **JJ7.1
Blending Materials Science, Nanotechnology, and Oncology through a Physical Sciences Perspective.
Larry Nagahara 1
1 Office of Physical Sciences - Oncology, National Cancer Institute, Bethesda, Maryland, United States
Show AbstractThe National Cancer Institute (NCI) is exploring new and innovative approaches to better understand and control cancer. By partnering with scientists from various non-biology disciplines, NCI envisions novel approaches to help generate answers to some of the major questions and barriers in cancer research. Interfacing materials science and nanotechnology with oncology has brought significant advancements and potentially novel breakthroughs in the way we clinically diagnose and treat cancer. One of NCI’s newest initiatives, the Physical Sciences in Oncology Initiative, attempts to better understand the physical laws and principles that shape and govern the emergence and behavior of cancer. Researchers examine non-traditional approaches to cancer research by bringing a physical sciences perspective to explore four thematic areas, namely, the physical laws and principles of cancer; evolution and evolutionary theory of cancer; information coding, decoding, transfer and translation in cancer; and de-convoluting cancer’s complexity. In this talk, examples of blending materials science and nanotechnology with a physical sciences perspective on oncology will be presented to illustrate that fostering the development of innovative ideas and new fields of study could lead to a paradigm shift in the way we understand and ultimately and treat cancer.
3:00 PM - JJ7.2
Highly Sensitive SERS Nanoprobes Based on Hollow Au/Ag Nanoshell Embedded Silica Nanospheres for In vivo Multiplex Detection.
Homan Kang 1 , Sinyoung Jeong 1 , Jiyoung Kim 1 , San Kyeong 1 , Jinjoo Chae 1 , Bong-Hyun Jun 1 , Ho-young Lee 1 , Dae Hong Jeong 1 , Yoon-Sik Lee 1
1 , Seoul national university, Seoul Korea (the Republic of)
Show AbstractMetal nanoshells have been extensively studied because of their high surface area and unique optical properties. As a result of these properties, the metal nanoshells play an important role in various fields such as catalysis, drug delivery, optical imaging, and photothermal therapy. In particular, hollow Au/Ag nanostructures have tunable extinction band from visible to near infrared (NIR) region (ca. 400-1200 nm), exhibiting both surface plasmon resonance and scattering.SERS (surface-enhanced Raman scattering) is a highly sensitive Raman spectroscopic technology. It has many advantages such as lack of photo-bleaching, narrow band width, and only single laser excitation is required for detection of multiple targets. Even though SERS has these advantages, SERS nanoprobes need to be improved in sensitivity and tissue penetration ability in vivo SERS application.In this study, we report the preparation of hollow Au/Ag nanoshells embedded silica nanospheres (GNES) as SERS active nanoprobes. The Au/Ag nanoshells were formed on the surface of silica sphere from Ag nanoparticles coated on silica sphere via galvanic replacement reaction. Then, simple aromatic Raman compounds were absorbed on the Au/Ag surface and subsequently encapsulated with silica shell. The GNES exhibited highly sensitive signals due to their localized surface electromagnetic field and the assembled multiple Au/Ag nanoshells on silica sphere. In addition, it shows extinction (absorption/scattering) in NIR region (the transparent window of biological tissue), which shows a feasibility for use as a SERS nanoprobe in vivo optical imaging.
3:15 PM - JJ7.3
Tantalum Oxide Nanoparticles: Modular Construction of New Contrast Agents for X-Ray/CT Medical Imaging.
Robert Colborn 1 , Peter Bonitatibus 1 , Matthew Butts 1 , Greg Goddard 1 , Hubert Lam 1 , Paul Buckley 1 , Andrew Torres 1 , Brian Lee 1 , Paul Fitzgerald 1 , Michael Marino 1
1 Chemical Nanotechnology, GE Global Research, Niskayuna, New York, United States
Show AbstractThere has been significant research and discussion concerning the use of nanoparticles in biological applications1. In particular, for medical contrast agents, a nanoparticle offers the potential for many signaling atoms in a single entity. The challenges for a nanoparticle team include synthesis, characterization and evaluation in the application of interest. We will describe the rationale that led us to develop nanoparticles based on tantalum oxide cores for x-ray/CT imaging2 . There have been recent publications in this area3-4. Our synthesis typically relies on a two-step approach such that the nanoparticle cores are prepared in a first step. For the tantalum oxide cores, the process is a modified sol-gel approach with controlled hydrolysis of tantalum alkoxide in the presence of additional ligands that provide stabilization against rapid agglomeration of the particles. In the second step, we create a stabilizing shell for the particle by introducing coating ligands. There are several advantages to the two-step process including tighter control over the size distribution of the cores and the ability to study effects of the coating ligands without interference from variations in the core.We will discuss our synthesis of water soluble tantalum oxide nanoparticles and their characterization. In particular, we will describe studies directed toward size control of the particles and the resultant effects on bioretention5. We will also discuss some process oriented experiments that allow for multiple gram synthesis. Preliminary imaging experiments will also be included.References1. Riehemann, K.; Schneider, S. W.; Luger, T. A.; Godin, B.; Ferrari, M.; Fuchs, H. Angew. Chem. Int. Ed. 2009, 48, 872.2. Bonitatebus, P. J.; Colborn, R. E.; Kulkarni, A. M.; Torres, A. S.; Bales, B. C.; Axelsson, O. In US Patent Application 2007/0122620; General Electric: US, 2007.3. Bonitatibus, P. J., Jr.; Torres, A. S.; Goddard, G. D.; Fitzgerald, P. F.; Kulkarni, A. M. Chem. Commun. 2010, 46, 8956.4. Oh, M. H.; Lee, N.; Kim, H.; Park, S. P.; Piao, Y.; Lee, J.; Jun, S. W.; Moon, W. K.; Choi, S. H.; Hyeon, T. J. Am. Chem. Soc. 2011, 133, 5508.5. Choi, H. S.; Liu, W.; Misra, P.; Tanaka, E.; Zimmer, J. P.; Ipe, B. I.; Bawendi, M. G.; Frangioni, J. V. Nat. Biotech. 2007, 25, 1165.
3:30 PM - JJ7.4
Biocompatible Hybrid Plasmonic-Magnetic Nanoparticles for Bioimaging.
Georgios Sotiriou 1 , Ann Hirt 2 , Pierre-Yves Lozach 3 , Alexandra Teleki 1 , Frank Krumeich 1 , Sotiris Pratsinis 1
1 Particle Technology Laboratory, ETH Zurich, Zurich Switzerland, 2 Department of Geophysics, ETH Zurich, Zurich Switzerland, 3 Institute of Biochemistry, ETH Zurich, Zurich Switzerland
Show AbstractHybrid plasmonic-magnetic nanoparticles possess properties originating from each individual material. Such properties are beneficial for biological applications including bioimaging, targeted drug delivery, in vivo diagnosis and therapy. Limitations regarding their stability and toxicity, however, challenge their safe use [1]. Here, the one-step flame synthesis of composite silica-coated Ag/Fe2O3 nanoparticles is demonstrated. The hermetic SiO2 coating [2] does not influence the morphology, the superparamagnetic properties of the iron oxide particles and the plasmonic optical properties of the silver particles. It does prevent, however, the release of toxic Ag+ ions from the nanosilver surface [3,4] and reduces the interaction field among the iron oxide particles, resulting in a stable suspensions with no signs of agglomeration (flocculation) and sedimentation. The feasibility of these multi-component nanoparticles with superior properties and performance is explored by their specific binding with live tagged cells, and the detection of the latter is demonstrated. Therefore, the hybrid SiO2-coated Ag/Fe2O3 nanoparticles do not exhibit the limiting physical properties of each individual component, while retain all the desired ones, facilitating their safe employment in such bio-applications.References[1] Sotiriou, G. A., Hirt, A. M., Lozach, P. Y., Teleki, A., Krumeich, F. & Pratsinis, S. E. Hybrid, silica-coated, Janus-like plasmonic-magnetic nanoparticles. Chem. Mater. 23, 1985-1992 (2011).[2] Sotiriou, G. A., Sannomiya, T., Teleki, A., Krumeich, F., Vörös, J. & Pratsinis, S. E. Non-toxic dry-coated nanosilver for plasmonic biosensors. Adv. Funct. Mater. 20, 4250-4257 (2010).[3] Sotiriou, G. A. & Pratsinis, S. E. Antibacterial activity of nanosilver ions and particles. Environ. Sci. Technol. 44, 5649-5654 (2010).[4] Sotiriou, G. A., Teleki, A., Camenzind, A., Krumeich, F., Meyer, A., Panke, S. & Pratsinis, S. E. Nanosilver on nanostructured silica: Antibacterial activity and Ag surface area. Chem. Eng. J. 170, 547-554 (2011).
3:45 PM - JJ7.5
Novel Core-Shell Magnetic Nanoparticles as Highly Efficient Contrasting Agents for Magnetic Resonance Detection.
Huilin Shao 1 2 , Tae-jong Yoon 1 3 , Ralph Weissleder 1 4 , Hakho Lee 1
1 , Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States, 2 Biophysics Program, Harvard Medical School, Boston, Massachusetts, United States, 3 Department of Applied Bioscience, CHA University, Seoul Korea (the Republic of), 4 Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States
Show AbstractMagnetic nanoparticles (MNPs) with high magnetic moments and small size are under active development for biomedical applications. Ferromagnetic metals, rather than their oxides, have been suggested as an ideal constituent for MNPs because of their superior magnetization. Unfortunately, monometallic MNPs typically require protective layers to prevent progressive oxidation. To date, most core/shell approaches have yielded sub-optimal magnetization, as the shell was formed either by oxidizing the core or by coating it with non-magnetic materials. Here we describe a new approach to prepare highly magnetic, monometallic MNPs Fe@MFe2O4, M = Fe, Mn, Co. The Fe cores were first enlarged to increase the overall magnetization. Protective ferrite shells were then grown onto the cores and can be metal-doped to further improve magnetization. TEM analysis confirmed the encasing of crystalline ferrite to provide robust protection on the Fe core. The resultant particles exhibited a novel magnetic feature: the presence of hysteresis but only negligible remanence. Comprehensive numerical analysis revealed that the ferromagnetic core and the superparamagnetic shell have a cooperative effect on magnetization. Thus, whilst the Fe-cores have non-zero coercivity, the ferrite shells effectively reduce it by leading the magnetization at low external magnetic fields. This allows the particles to achieve high transverse relaxivity (r2) of 365 s-1 mM-1 and yet remain superparamagnetic for biological applications. With specific antibody conjugation, the highly magnetic Fe@MnFe2O4 has a detection sensitivity of ~10 cancer cells in human whole blood. A comparative study of phantoms also confirmed the superiority of Fe@MnFe2O4 as a MR contrast agent; compared to the widely-used CLIO (cross-linked iron-oxide), Fe@MnFe2O4 was able to produce the same signal changes at ~10 times lower doses. The same trend was observed in preliminary in vivo imaging. Fe@MnFe2O4 has been shown to be safe for both in vitro and in vivo applications.
4:30 PM - **JJ7.6
Hierarchical Nanostructured Interfaces for Enhanced Drug Delivery.
Tejal Desai 1
1 Bioengineering and Therapeutic Sciences, UCSF, San Francisco, California, United States
Show AbstractEfficient and effective drug delivery remains an important challenge in medicine. Continuous release of therpeutic agents over extended periods of time, local targeted delivery at a predetermined rate to overcome systemic toxicity, and increasing patient compliance are some of the unmet needs. This talk will discuss in vivo drug delivery strategies that capitalize on the use of micro and nanotechnology. By taking advantage of our ability to control topography and chemistry at submicron size scales, we have developed organic and inorganic interfaces which increase epithelial permeability and modulate release kinetics. In particular, we will discuss approaches to enhance both oral and transdermal delivery. Due to our ability to create well defined nanoscale features in a variety of non-planar biocompatible materials, we can design materials which intimately interact with cellular barriers, altering both mechanical and chemical signalling. Nanostructured interfaces can not only add functionality to current drug delivery platforms but also be an enabling technology to enhance therapeutic delivery for a variety of applications.
5:00 PM - JJ7.7
Mixed Micelles Formed from Acid- and Urea-Functional Polycarbonates for High Cargo Loading Capacity and Kinetic Stability.
Wei Cheng 1 , Chuan Yang 1 , Jeremy P.K. Tan 1 , Amalina Ebrahim Attia 1 , Chloe Yi Ting Tan 1 , Alshakim Nelson 2 , James L. Hedrick 2 , Yi-Yan Yang 1
1 , Institute of Bioengineering and Nanotechnology, Singapore Singapore, 2 , IBM Almaden Research Center, San Jose, California, United States
Show AbstractThe major obstacles for micellar drug-delivery systems are the lack of stability when exposed to infinite dilution after their in vivo administration, and low cargo loading capacity. To address these problems, in our laboratory, a series of biodegradable triblock copolymers of PEG, poly(ethyl carbonate) and acid-functional polycarbonate with precisely controlled molecular weight and well-defined structure were synthesized via organocatalytic living ring opening polymerization, and self-assembled into nanostructures with narrow size distribution. These nanostructures demonstrated exceptionally high loading capacity of an amine-containing cargo (i.e. they achieved high loading level of about 60 (wt)% for doxorubicin (DOX), an anticancer drug containing one amine group) due to electrostatic interactions between the amine group of the cargo and the acid functional group of the polymer. However, DOX-loaded acid-functional micelles were kinetically unstable. To improve kinetic stability, a urea-functional polycarbonate was mixed with an acid-functional polycarbonate to form mixed micelles that were stabilized by hydrogen bonding interactions between the urea and acid functional groups in the micellar core. The mixed micelles demonstrated nanosize with narrow size distribution, retained high cargo loading capacity, and greatly improved the kinetic stability. In addition, DOX release from the mixed micelles was sustained without obvious initial burst release, and DOX-loaded mixed micelles were able to kill HepG2 human carcinoma cell line efficiently. The biodistribution studies of the DOX-loaded micelles in mice showed that DOX content in the heart was much lower when delivered by the mixed micelles as compared to the acid-functional micelles, indicating lower cardiotoxicity risk. Therefore, these mixed micelles have a great potential as a carrier for delivery of various anticancer drugs that contain amine functional groups.Comments: Appreciate it very much if you can offer me an opportunity to present this work as an oral presentation so that my institute will provide me financial support to attend this meeting.
5:15 PM - JJ7.8
Luminescent and Magnetic Properties of Gd-Substituted β Phase-Na(Y,Gd)F4:Yb,Er up-Conversion Nanoparticles for Bio-Imaging.
Ho Seong Jang 1 , Kipil Lim 1 , Kyoungja Woo 1
1 , Korea Institute of Science and Technology, Seoul Korea (the Republic of)
Show AbstractTrivalent lanthanide ion-doped inorganic nanoparticles, i.e. nanophosphors, have highly attracted many scientist’s notice in biological field as well as materials science due to their high chemical stability, no photobleaching compared with conventional organic fluoropores, and Cd-free composition and non-blinking luminescence unlike well-known CdSe-based quantum dots. In particular, up-conversion nanophosphors showing visible light emission under near-infrared (NIR) light excitation can act as a superior imaging agent in bio-labeling including cancer cell imaging and in vivo imaging, and targeting, and diagnostics since NIR light has deep penetration depth into biological system and does not induce fluorescence from tissues or cells, resulting in high signal to noise ratio.In this study, we synthesized Gd-substituted β-phase NaYF4 co-doped with Yb3+ and Er3+ ions and investigated its luminescent properties. For biological in vivo application, it is desirable that the size of the nanoparticles is smaller than 10 nm. To the best of our knowledge, however, there are rare reports on ultrasmall β-phase NaYF4:Yb3+,Er3+ (β-NaYF4:Yb,Er) nanoparticles below 10 nm. When we substituted Y sites with Gd3+ ions, particle size of β-Na(Y,Gd)F4:Yb,Er was decreased with increasing Gd concentration and ultrasmall up-conversion nanophosphors with the size of 8.3 nm were successfully synthesized. Since the ultrasmall size of β-Na(Y,Gd)F4:Yb,Er was achieved via only Gd substitution without accompanying the decrease of reaction temperature and time, synthesized nanophosphors maintained high crystallinity. Despite of high crystallinity, smaller size induced drastic increase of surface defects per unit volume, which causes luminescence quenching. To compensate weaker luminescence intensity, core/shell structure was adopted. The core/shell nanophosphor showed bright green emission peaking at 542 nm under excitation with 980 nm. Also, introduction of Gd3+ ions to the nanophosphors let the β-Na(Y,Gd)F4:Yb,Er have magnetic properties, which enable the nanophosphors to enhance relaxation of water protons surrounding them. Thanks to these advantages, the β-Na(Y,Gd)F4:Yb,Er core/shell nanoparticles can be a promising agent for magnetic resonance imaging as well as fluorescence imaging for cancer application.In summary, highly luminescent ultrasmall β-Na(Y,Gd)F4:Yb,Er core/shell nanoparticles were synthesized. The effect of Gd addition on the morphology, luminescence and magnetic properties of the nanophosphor was investigated. Consequently, ultrasmall β-Na(Y,Gd)F4:Yb,Er core/shell nanoparticles with up-conversion luminescence and superparamagnetism are acceptable for cancer application.
5:30 PM - JJ7.9
Surface Engineered Porous Silicon-Based Nanostructures for Cancer Therapy.
Ester Segal 1 2 , Adi Balter 3 , Naama Massad-Ivanir 1
1 Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa Israel, 2 The Russell Berrie Nanotechnology Institute, Technion - Israel Institute of Technology, Haifa Israel, 3 The Inter-Departmental Program of Biotechnology, Technion - Israel Institute of Technology, Haifa Israel
Show AbstractIn recent years, nanostructured porous Silicon (PSi) has emerged as a promising and versatile biomaterial for drug delivery applications owing to its biodegradability and biocompatibility. PSi exhibits several properties that make it an attractive platform for drug delivery applications: The electrochemical synthesis allows construction of tailored pore sizes and volumes that are controllable from the scale of nanometers to microns; the surface chemistry of PSi can be easily modified to produce surfaces favorable for drug adsorption and entrapment.Our work aims to develop new PSi-based nanostructures for delivering antineoplastic drugs. We focus on engineering the PSi nanostructure and its surface chemistry to control the loading and release of Mitoxantrone (MTX, a model anticancer drug). Different PSi films are prepared by electrochemical anodization of Si in hydrofluoric acid solutions. Etching conditions are adjusted to optimize the PSi nanostructure to maximize the drug loading. We find that PSi films characterized by interconnecting cylindrical pores ranging in diameter from 5-10 nm, an average thickness of 2.3 µm, and porosity of 64% are optimal for MTX loading. Following electrochemical fabrication, the films are chemically modified by thermal hydrosilylation (with 1-dodecene or undecylenic acid), and the drug payload is incorporated within the porous nanostructure. Two loading routes are explored: (i) physical adsorption, and (ii) covalent attachment of the drug. Significant differences in drug release profiles are found between the dodecene-modified PSi and freshly-etched samples. Thus, by changing the surface properties of the PSi from moderately hydrophilic to hydrophobic, the release of MTX can be slowed by a factor of 20. Flow cytometry assays of cell viability confirm that MTX released from the different PSi-loaded systems maintain significant cytotoxic functionality towards MDA-MB231 cancer cell lines.
5:45 PM - JJ7.10
Maximizing the Sensitivity of SQUID Remanence Based Cancer Detection by Optimizing Superparamagnetic Nanoparticles.
Dale Huber 1 , Erika Cooley 1 , Todd Monson 1 , Danielle Fegan 2 , Natalie Adolphi 3 , H. Bryant 2 , Helen Hathaway 3 , Debbie Lovato 3 , Kimberly Butler 3 , Trace Tessier 2 , Richard Larson 3 , Edward Flynn 2
1 Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico, United States, 2 , Senior Scientific LLC, Albuquerque, New Mexico, United States, 3 , University of New Mexico, Albuquerque, New Mexico, United States
Show AbstractSQUID remanence is a powerful technique that allows very early detection of cancer due to the extremely low background. It works by magnetizing targeted superparamagnetic nanoparticles in vivo, and detecting the magnetic relaxation of only the tissue-bound nanoparticles. The signal varies linearly with the amount of cancer, whose location in the body can be determined through the use of a multi-channel detection system. While this is a versatile and extraordinarily sensitive technique, there are stringent requirements for the nanoparticles which must have a Néel relaxation time in a narrow time window. The primary source for potential improvements in sensitivity is in the control of properties of the superparamagnetic nanoparticles. The ideal particles are spheres with narrow polydispersity, no agglomeration, a biocompatible coating, and can be synthesized extremely reproducibly. These stringent requirements, particularly the level of reproducibility required, have necessitated the development of new chemical approaches to the synthesis of these nanoparticles. The basic approach developed is to perform a high temperature thermal decomposition of organometallic precursors to synthesize magnetite nanoparticles of approximately 24 nm in diameter. A ligand exchange is performed to provide new functionality for further covalent attachment of biocompatible polymers and targeting antibodies. The ongoing development and optimization of the complex multi-component material will be discussed, as will its use in clinically relevant measurements (in vitro and in vivo). This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. Department of Energy, Office of Basic Energy Sciences user facility. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.