John A. Carlisle Advanced Diamond Technologies, Inc.
Martin Eickhoff Technische Universitaet Muenchen
Jose A. Garrido Technische Universitaet Muenchen
Janos Voeroes University and ETH Zurich
Erika Johnston Genzyme Corporation
Monday AM, November 27, 2006
Room 202 (Hynes)
9:30 AM - **D1.1
Bionanoarrays Prepared by Massive Parallel Dip-Pen Nanolithography
Chad Mirkin 1 2 , Khalid Salaita 1 2 , Yuhuang Wang 1 2 , Rafael Vega 1 2 , Joseph Kakkassery 1 2 , Clifton Shen 1 2 , Daniel Maspoch 1 2 Show Abstract
1 International Institute for Nanotechnology, Northwestern University, Evanston, Illinois, United States, 2 Department of Chemistry, Northwestern University, Evanston, Illinois, United States
The emerging field of nanobiotechnology relies on precise patterning of biological molecules on surfaces with nanometer resolution. Examples include the generation of DNA, protein, virus, and cell arrays that have potential biosensing, proteomics, and theranostics applications. There are currently a number of techniques for generating nanoscale features of biological molecules. These include electron-beam lithography, Dip-Pen Nanolithography (DPN), nanografting, nanoimprint lithography, nanopipet deposition, and contact printing. Each of these techniques has a set of capabilities that differentiate it from the other ones, and they all possess strengths and weaknesses with regard to resolution, speed, materials compatibility, complexity, and cost.DPN, a scanning-probe-based lithography in which an AFM tip is used to generate nanoscale biological patterns by directly transferring biomolecules to a surface, offers a number of realized and potential advantages over other nanopatterning techniques. It is substrate general and the patterning is typically performed under ambient conditions, which is critical for biomolecules. However, in its current state of development, the biggest limitation of DPN is its speed, especially when carried out in the context of single pen experiments. In addition, the bionanoarrays generated by DPN thus far are limited to a surface area of 100 μm × 100 μm using conventional single pens. Recently, DPN has evolved from a serial-based single pen experiment to a parallel patterning tool for generating complex nanoscale features over a large area.In this talk, we will discuss the massive parallel writing capabilities of DPN using a 2-D tip-array consisting of 55,000 individual tips (NanoPrint Array™). We will also discuss the strategies that we employed to perfectly align all of the 55,000 tips with the substrate. High-throughput DPN allowed us to fabricate in 20 minutes 88 million 100 nm-size high-resolution features. The 2-D tip array was used in the direct and indirect write approaches to generate nanoscale biological features. In particular, we have generated fibronectin and biological lipids nanoarrays over 1 cm2 substrate areas.
10:00 AM - D1.2
Lab-on-a-Chip Devices with Nanoscale Surface Topography for Neural Electrophysiological Applications.
Ludovico Dell'Acqua-Bellavitis 1 3 , Richard Siegel 2 3 Show Abstract
1 Engineering Science, Rensselaer Polytechnic Institute, Troy, New York, United States, 3 Nanotechnology Center, Rensselaer Polytechnic Institute, Troy, New York, United States, 2 Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York, United States
This study is aimed at developing and fabricating novel in vitro electrophysiological devices capable of concurrently enhancing cell-biomaterial interaction and signal discrimination and resolution. The approach combines (i) the design and fabrication of integrated circuit platform (IC) and (ii) the synthesis ex situ of electrically insulated and aligned conducting nanowire arrays within a single device for electrophysiological studies of neuronal cells. The IC platform, which features an array of electrically-insulated electrodes deposited on thermally-grown silicon dioxide, was fabricated at three different scales of resolution to enable recordings of field potentials, action potentials and ionic channel potentials, respectively, at the multicellular, intercellular and intracellular levels (1).A conducting gold-plated copper / anodized alumina composite construct was fabricated as the interface between neuronal cells and the IC platform. The fabrication process was comprised of the following steps: (i) synthesis of anodized alumina templates (2); (ii) conformal copper metallization within the pores of anodized alumina templates; (iii) electropolishing of the excess copper on the anodized alumina templates; (iv) selective alumina etching; and (v) selective electroless gold deposition on the copper nanowires. The composites were then positioned in intimate contact with the previously manufactured multiple electrode array, therefore constituting an interface between an underlying IC platform and neuronal cells.The device was then interfaced with external amplification and data acquisition hardware and software in order to either record bioelectric signals from both single and multiple neural cells or to electrically stimulate them with ultimate nanometric space resolution.This work was supported by Philip Morris USA and the Nanoscale Science and Engineering Initiative of the National Science Foundation under NSF Award No. DMR-0117702.References(1)L.M. Dell’Acqua-Bellavitis, J.D. Ballard, R. Bizios, R.W. Siegel (2005) Synthesis of nanoscale devices for neural electrophysiological imaging, Mater. Res. Soc. Symp. Proc. 872, J18.17.1.(2) G.W. Meng, Y.J. Yung, A.Y. Cao, R. Vajtai, P.M. Ajayan (2005) Controlled fabrication of hierarchically branched nanopores, nanotubes, and nanowires, Proc. Natl. Acad. Sci. USA 102, 7074-7078.
10:15 AM - D1.3
Stack of BioCells Converting ATP to Electrical Power and Possible Applications.
Vishnu Baba Sundaresan 1 , Donald Leo 1 , Andy Sarles 1 Show Abstract
1 Mechanical Engineering Department, Virginia Tech, Blacksburg, Virginia, United States
10:30 AM - D1.4
Use of sub-10 nm Diameter Upconversion Nanophosphors as Bio-labels.
Shuang Fang Lim 1 , Robert Riehn 1 , Chih-kuan Tung 1 , David Tank 1 , Robert Austin 1 , William Ryu 2 , Margarita Herrera-Alonso 3 , Robert Prud'homme 3 Show Abstract
1 Physics, Princeton University, Princeton, New Jersey, United States, 2 Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States, 3 Chemical Engineering, Princeton University, Princeton, New Jersey, United States
We have synthesized rare-earth doped sub-10 nm diameter upconverting yttrium oxide based nanophosphors by flame spray pyrolysis. We show that upconversion nanophosphors can be imaged by both infrared excitation and electron excitation in a scanning electron microscope. We have investigated the optical properties of 50-200 nm diameter sized nanophosphors, and found a square-dependence of the emitted visible fluorescence on the infrared excitation, and verified that under electron excitation similar narrow band emission spectra can be obtained as is seen with IR upconversion. We have surface functionalized the nanophosphors making them suitable for bio labeling. The viability of the nanoparticles for biological imaging was confirmed by imaging the digestive system of the nematode worm C. elegans, confirming that the upconversion nanophosphors can be identified in a scanning electron microscope at high spatial resolution.
Monday AM, November 27, 2006
Room 202 (Hynes)
11:15 AM - **D2.1
Modular Designed Functional Nanoparticles for Clinical Theranostics.
Dar-Bin Shieh 1 , Cheng-Shen Yeh 2 , Yonhua Tzeng 3 4 Show Abstract
1 Institute of Oral Medicine and Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan Taiwan, 2 Department of Chemistry and Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan Taiwan, 3 Institute of Nanotechnology and Microsystems Engineering and Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan Taiwan, 4 Dept. of Electrical & Computer Engineering, Auburn University, Auburn University, Alabama, United States
11:45 AM - D2.2
Gold Nanoparticle Covalent Labeling of Proteins at Specific Sites.
Marie-Eve Aubin-Tam 1 , Kimberly Hamad-Schifferli 2 1 Show Abstract
1 Biological Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States, 2 Mechanical Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
Site-specifically labeling of a protein is challenging as the nanoparticle can link in many number of ways on the protein. An ideal labeling approach would be targeted to a specific amino acid and would be independent of physical characteristics of the milieu like pH, salt concentration or temperature. Furthermore, for most applications of gold NP-protein conjugates, it is crucial that labeling does not distort the protein structure, hamper any interactions of the protein with its partners or obstruct its active site. We report covalent labeling of a 1.5nm gold nanoparticle on specific amino acids of the protein Cytochrome c. Multiple labeling sites and nanoparticle surface chemistry are considered to minimize protein denaturation. This study is of great importance for applications in which biomolecules are linked to nanoscale structures, such as imaging, sensing, and microfluidic devices.Our labeling strategy aims to attach the gold nanoparticle at a specific single surface cysteine. The chemistry of labeling relies on the gold-thiol covalent bond. Nanoparticles with negatively, positively charged and neutral ligand are successfully labeled with Cytochrome c. The conjugates are purified by gel electrophoresis or HPLC. The protein secondary structure is studied by circular dichroism. We find that changing the chemical moiety on the end of the ligand can dramatically affect the structure of the Cytochrome c, supporting that nanoparticle ligands play a major role in the protein-nanoparticle interactions.Cytochrome c is mutated in order to present single cysteine residues at various positions on its surface in order to identify how the secondary structure of the labeling site and its surrounding amino acids affect the propensity of the protein structure to be disturbed by the nanoparticle. The protein structural disturbance is rationalized by considering the electrostatic interaction likely to occur between the nanoparticle ligand molecules and the amino acids in the vicinity of the labeled surface cysteine. Structural disturbance of Cytochrome c is known to affect its redox potential. Thus, the protein electrochemistry is characterized by cyclic voltammetry.
12:15 PM - D2.4
Fluorescent Silica Nanoparticles: Probes for Imaging and Sensing in Biology
Andrew Burns 1 , Prabuddha Sengupta 2 , Ethan Chiang 2 , Erik Herz 1 , Barbara Baird 2 , Ulrich Wiesner 1 Show Abstract
1 Materials Science & Engineering, Cornell University, Ithaca, New York, United States, 2 Chemistry and Biochemistry, Cornell University, Ithaca, New York, United States
The study of the colloidal chemistry of silica has created a versatile toolbox for the design of novel materials on the nanoscale. We have integrated this knowledge of silica sol-gel chemistry with the wide array of fluorescent organic dyes to develop a family of bright and stable, core-shell, fluorescent silica nanoparticles. These novel materials show considerable enhancements in brightness (tens- to hundred-fold compared to single fluorophores) through multiple fluorophore encapsulation and fluorescence enhancement effects, in addition to increased resistance to photobleaching and solvatochromic shifts for encapsulated dyes. These nanoparticles have been further developed as a platform for quantitative ratiometric sensing and imaging of chemical concentrations in biological samples. The co-localizaton of sensor and reference dye molecules in a core-shell architecture is an optimized design for sensing, placing the sensor dyes in the high surface area outer shell, while sequestering the reference dyes deep within the particle, away from environmental perturbations. In order for these particles to become effective tools for biologists, their interactions with cell surfaces must be addressed. Towards that end, we have developed several targeting methods to mediate specific labeling and uptake of particles in various cell lines. In addition, given that theses particles are natively electrostatically stabilized, the question of colloidal stability in biological media must be addressed and we will present our recent findings in the development of highly functional nanoparticles for biology.
12:30 PM - D2.5
Magnetic Nanoparticle-biomolecule Interfaces: Synthesis, Characterization, and Implementation in Bioengineering Applications.
Kimberly Hamad-Schifferli 1 2 Show Abstract
1 Mechanical Engineering, MIT, Cambridge, Massachusetts, United States, 2 Biological Engineering, MIT, Cambridge, Massachusetts, United States
12:45 PM - D2.6
Particle Size Effects in Magnetite Nanoparticle Uptake into Cells
Juan Meng 1 , Patrick Clasen 2 , Tracy Vu 1 , Shuailei Ma 2 , Christopher J. Kiely 2 , Martin P. Harmer 2 , Winston O Soboyejo 1 Show Abstract
1 Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey, United States, 2 Materials Science and Engineering, Lehigh University, Bethlehem, Pennsylvania, United States
This paper presents the results of an experimental study of the effects of magnetite nanoparticle size on the uptake of nanoparticles into breast cancer and normal breast cells. The uptake of the nanoparticles is studied using a combination of transmission electron microscope and quantitative image analysis. The particle size effects in receptor-mediated and non-receptor-mediated endocytosis are then considered within a theoretical framework that considers the combined effects of adhesive forces and elastic energy on the entry of nanoparticles into biological cells. The results suggest an optimal nanoparticle size that is consistent with the experimental observations of 20-30nm.
D3: Cell Surface Interactions
Monday PM, November 27, 2006
Room 202 (Hynes)
2:30 PM - **D3.1
Molecularly Engineered Surfaces for Cell Biology.
George Whitesides 1 , J. Jiang 1 , D. Bruzewicz 1 , A. McGuidon 1 , N. Shen 1 , A. Wong 1 , D. Weibel 1 , J. Kriebel 1 , M. Butte 1 Show Abstract
1 The Whitesides Research Group, Harvard University, Cambridge , Massachusetts, United States
3:00 PM - D3.2
Engineering Cellular Behavior via Cell-Surface Interactions with Fibronectin Nanoislands.
John Slater 1 , Wolfgang Frey 1 Show Abstract
1 Department of Biomedical Engineering and Center for Nano and Molecular Science and Technology, University of Texas at Austin, Austin, Texas, United States
Intracellular signaling events initiated by cell-surface interactions have proven to be an influential component governing cellular behavior. These interactions are mediated by integrins that aggregate into small clusters to form either focal complexes or focal adhesions. Focal complexes are smaller, typically less than 1 µm2, and less molecularly complex than their mature counterparts. With the recent explosion of nanofabrication techniques much