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
Monday AM, 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 Show Abstract
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
For 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 Show Abstract
1 Department of Materials Sciences and Engineering, National Chiao Tung University, Hsin Chu, TAIWAN, Taiwan
Thermosensitive 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 Show Abstract
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)
Accuracy 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 Show Abstract
1 Department of Chemical and Biomolecular Engineering, UCLA, Los Angeles, California, United States
Cancer 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 Show Abstract
1 , Yonsei University, Seoul Korea (the Republic of)
One 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 Show Abstract
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
One 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 Show Abstract
1 Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
Photoactivatable 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 Show Abstract
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
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
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 Show Abstract
1 Materials Science and Engineering, Stanford University, Stanford, California, United States
Reproducible 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 . 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 .References:  Gaster RS, Hall DA, et al., Nature Medicine, 15, 1327-1332, 2009. Osterfeld SJ, Yu H, et al., PNAS, 105, 20637-20640, 2008. Hall DA, Gaster RS, et al., Biosensors and Bioelectron., 25, 2051-2057, 2010. Gaster RS, Hall DA, Wang SX, Nano Letters, published online, DOI: 10.1021/nl1026056. 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 Show Abstract
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
In 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 Show Abstract
1 Chemistry, Kansas State University, Manhattan, Kansas, United States
Globally, 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 Show Abstract
1 , MPI for Intelligent Systems, Stuttgart Germany, 2 Physical Chemistry, Heidelberg University , Heidelberg Germany, 3 Department of Dermatology, Göttingen University, Heidelberg Germany
The 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 Show Abstract
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
Biophysics 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 Show Abstract
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
Implantable 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 Show Abstract
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
Besides 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 Show Abstract
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
We 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 Show Abstract
1 Electrical Engineering, Univ. of Southern California, Los Angeles, California, United States
Biomarker 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.
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
Tuesday PM, November 29, 2011
Exhibition Hall C (Hynes)
1:00 AM -
JJ5.50 TRANSFERRED TO JJ3.8
JJ3: Bio-Nano-Material for Cancer I
Tuesday AM, November 29, 2011
Room 203 (Hynes)
9:30 AM - **JJ3.1
Quantum Dots Capable of Efficient Translocation through Nuclear Pore Complexes.
Jan Liphardt 1 Show Abstract
1 Physics, UC Berkeley, Berkeley, California, United States
The 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 Show Abstract
1 Surgery and Cancer, Imperial College London, London United Kingdom
Nanoparticles 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 Show Abstract
1 Biological and Mechanical Engineering, MIT, Cambridge, Massachusetts, United States
The 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 Show Abstract
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
We 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 Show Abstract
1 Ceramics Division, National Institute of Standards and Technology, Gaithersburg, Maryland, United States
A 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 Show Abstract
1 , Nanotechnology Characterization Laboratory, SAIC-Frederick, Inc., Frederick, Maryland, United States
Recent 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 Show Abstract
1 , Institute of Bioengineering and Nanotechnology, Singapore Singapore, 2 , IBM Almaden Research Center, San Jose, California, United States
Polymeric 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 Show Abstract
1 , INSA toulouse, Toulouse France
Up 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.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 Show Abstract
1 Materials Reliability Division, National Institute of Standards and Technology, Boulder, Colorado, United States
Nanoparticles 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 Show Abstract
1 Bioengineering Department, University of Louisville, Louisville, Kentucky, United States, 2 Conn Center for Renewable Energy Research, University of Louisville, Louisville, Kentucky, United States
Gold 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
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 Show Abstract
1 , Harvard Medical School - Massachusetts General Hospital, Boston, Massachusetts, United States
A 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 Show Abstract
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
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 op