SURE 2003 PROJECTS

The following research project descriptions are intended to give applicants to the CPIMA SURE program a feeling for the research opportunities within the four CPIMA partners - Stanford University, IBM Almaden Research Center, University of California at Berkeley and University of California at Davis - as well as international and industrial affiliates.

The projects are grouped according to the corresponding research site. Each mentor's name is listed before the title of the project. If you wish to find out more information about a particular mentor, click on the name of the mentor.

Stanford University (top)

1) Design and Synthesis of Components in Supported Bilayer Membranes.
2) Atomistic Modeling of Polymer-Surface Interactions.
3) Adhesion and Debonding of Polymer Interfaces.
4) Grafting of Polypeptides on Solid Substrates.
5) Polymer Hydrogels for Lab-on-a-Chip Applications.
6) 2D Crystals Subject to Flow.
7) Electrical and Optical Devices Based on Semiconducting Polymers.
8) The Dynamics of Single DNA Chains Under Shear in Two and Three Dimensions.

University of California - Berkeley (top)

9) Synthesis Understanding Cell-Cell Recognition in the Immune System.
10) Synthesis of Conducting Oligomers and Polymers.
11) Synthesis of Dendrimers and Highly Branched Polymers for Use as Artificial Enzymes in Catalysis.
12) Collective Molecular Recognition and Adhesion at Membrane-Membrane Interfaces.

University of California - Davis (top)

13) Nanoporous Electromagnetic Sensors.
14) Imaging based on Sum-frequency Spectroscopy.
15) Biosensing Membranes.
16) Biomembrane Materials.

17) Contact Nanopatterning: Control of Size and Chemistry of Nanofeatures.
18) The Behavior of Ultrathin Polymer Films in Confined Spaces.
19) Functionalized Thin Polymer Films.
20) Nanoparticles for Drug Delivery Applications.
21) Organic Catalysis: A New and Broadly Useful Strategy for Living Polymerization.
22) Novel Macromolecular Architectures Based on Biocompatible Aliphatic Polyesters.
23) Porosity in Thin Films: Generation, Characterization and Applications.
23.5) Protein folding -- Simulation and Analysis.

Agilent Tecnologies Laboratory, Palo Alto, CA (top)

24) Microfluidics and Biomolecular Sensors.

Max Planck Institute for Polymer Research, Mainz, Germany (top)

25) Reactions on Functionalized Plasma Polymer Films.
26) UV-based Patterning of Polymeric Substrates for Cell Culture Applications.

Institute of Polymer Research, Dresden, Germany (top)

27) Responsive Polymer Films from Mixed Brushes.
28) Analysis of Single Adsorbed Polymer Molecules.
29) Functional Polymers for Integration Tethered Lipid Bilayers on Solid Surfaces.
30) Biocompatible Surfaces Based on Dendritic Structures.

1) (S. Boxer) Design and Synthesis of Components in Supported Bilayer Membranes. (top)

The objective of this work is to create a new class of molecular systems that can be used to alter the self-assembly of supported bilayer membranes. Supported bilayers are two-dimensional fluids that can be contained within barriers or corrals that are patterned on surfaces. To date, such barriers have had static properties. In this project we will prepare barrier materials that can be switched with light or by a redox reaction such that the membrane fluidity properties are altered. This work will involve chemical synthesis, self-assembly on gold or on glass, surface characterization, and ultimately the further self assembly and characterization of supported lipid bilayer membranes over such switchable surfaces.

2) (K. Cho) Atomistic Modeling of Polymer-Surface Interactions. (top)

Understanding the physical states of polymer molecules attached to a solid surface is an important problem for device applications involving signal transduction between molecular materials and solid device materials. Biosensor is an example in which biochemical activity of a biomolecule induces an electronic or optical signal in solid materials through the polymer-surface interface. To develop a high resolution and multifunctional devices, it is essential to understand the detailed atomic scale properties of the interface. This project will apply accurate hydrocarbon many-body interatomic potential to molecular dynamics study of polymer molecules attached on solid surfaces. Different strategies of modifying surface properties will be investigated to control the polymer-surface interface interactions leading to potential control mechanisms for nanoscale surface patterning.

3)(R. Dauskardt) Adhesion and Debonding of Polymer Interfaces. (top)

Adhesion and reliability of interfaces are crucial for a range of advanced technologies including applications in the microelectronic and biomedical industries. This project will involve developing techniques to measure the macroscopic adhesion valuesof a range of polymer interfaces that involve thin polymer layers or films. Adhesion values will be related to the underlying structure of the interface, its chemistry, and the properties of the adjacent materials.

Polypeptides are macromolecules composed of one or more types of amino acids. Whereas naturally occurring polypeptides or proteins have important biological properties, this project takes a biomaterials point of view. We will explore a variety of ways of attaching polypeptides to solid substrates to prepare templates for controlled adsorption of polymers or proteins. This has potential applications in the development of biocompatible surfaces and in membrane separations. The project will involve chemical synthesis and characterization of interfacial properties.

5) (C.W. Frank) Polymer Hydrogels for Lab-on-a-Chip Applications. (top)

Many academic and industrial research groups are currently developing techniques for miniaturization of laboratory wet chemical procedures. Such "lab-on-a-chip" devices combine mixing, pumping, reaction, and separation procedures on a single substrate. This project will focus on the development of surface-attached polymer hydrogels, which may have applications in valve and pump designs. Chemical synthesis of hydrogel networks and characterization of swelling and deswelling behavior will be carried out.

6) (G. Fuller) 2D Crystals Subject to Flow. (top)

Many systems form 2D crystals at fluid interfaces. Examples include colloidal particles and proteins. In this project the action of flow fields on 2D crystals formed from micron-sized spheres will be examined. The influence of altering the interparticle potential through changes in the ionic strength of the bulk fluid phases on the process of shear-induced melting will be examined.

7) (M. McGehee) Electrical Fabricating Nanostructures with Semiconducting Polymers for Photovoltaic Cells and Light-Emitting Diodes. (top)

We will have opportunities for students to use self-assembly to make interpenetrating networks of organic and inorganic semiconductors for photovoltaic cells. A student could be involved in making the materials, characterizing them, or testing photovoltaic cells. We will also have opportunities to make polymer light-emitting diodes that will be incorporated into photonic crystals and biosensor modules.

8) (E. Shaqfeh) The Dynamics of Single DNA Chains Under Shear in Two and Three Dimensions. (top)

The project will involve experiments examining the dynamics of single DNA chains either free in a liquid or near a solid-liquid interface under flow using strong video microscopy. In particular, we shall examine how the dynamics of the chains are affected by flow type and interfacial interaction. These experiments will be compared to computer simulations of DNA dynamics using models that we have developed over the last five years.
Prerequisite: Chemical engineering or physics major preferred.

9) (A. Chakraborty) Synthesis Understanding Cell-Cell Recognition in the Immune System. (top)

A little over three years ago, it was observed that when T cells in the immune system recognize target cells from a vast pool of other healthy ones, a highly organized and patterned collection of different receptors and ligands forms in the intercellular junction. This recognition motif is called the immunological synapse. We pioneered the application of theoretical and computational methods to address questions such as: how does the synapse form? what is the biological function of the synapse? Our work, which highlights the importance of cell membrane shape fluctuations, also suggests the possibility of designing synthetic materials that can mimic the specificity of T cell recognition of antigen presenting cells. This SURE project aims to investigate some issues pertinent to the design of such biomimetic materials. The student will learn some immunology, polymer science, and sophisticated statistical mechanical methods.

10) (J. Fréchet) Synthesis of Conducting Oligomers and Polymers. (top)

Organic conducting molecules are finding numerous applications in areas such as molecular electronics, light emitting diodes, and photocells. This project will involve the synthesis of oligomers and polymers based on thiophenes and other aromatic building blocks, as well as block copolymers containing one conducting block and another block selected for its intrinsic properties such as surface activation, light harvesting, etc. The project will involve a variety of organic and polymer synthesis techniques, as well as physical measurements and possibly device fabrication.
Prerequisite: Chemistry major with a two semesters of undergraduate organic chemistry including laboratory.

11) (J. Fréchet) Synthesis of Dendrimers and Highly Branched Polymers for Use as Artificial Enzymes in Catalysis. (top)

This project involves the synthesis of large macromolecules with a globular shape that can function as nanometer size “reactors” in chemical transformations. The molecules are designed to concentrate reagents within the catalytic cavity where the transformation takes place, and to expel the products from this catalytic cavity after reaction. Key elements of this project involve the preparation of organic building blocks, frequently small organic dendrimers that can be rapidly assembled into the catalytic molecules, or of polymers with pendant functional groups that will form the core of the catalytic molecules.
Prerequisite: Chemistry major.

12) (J. Groves) Collective Molecular Recognition and Adhesion at Membrane-Membrane Interfaces. (top)

Numerous biological processes are mediated by the collective interaction between populations of receptors and ligands in the cell-cell junction. In addition to these specific binding events, large numbers of non-specific interactions contribute to the creation of a highly organized reaction environment. We will develop systems, based on various forms of the supported membrane technology, to measure and characterize collective intermembrane reactions. Initial emphasis will be directed towards the interactions between lipid membrane - coated micro- and nano- silica particles and membrane arrays supported on monolithic substrates. We are particularly interested in exploring the effects of membrane fluidity and adhesion - induced molecular rearrangements.

The development of optical and microwave methods to detect and characterize interactions between biomolecules in their physiological environments, in real time, and without the use of extrinsic tags or markers such as fluorescent dyes or conjugated enzymes is of great interest to map biochemical pathways that lead to disease states, monitor patients for clinically relevant analytes, detect infectious agents and environmental toxins, and develop drugs. It is highly desirable to measure these interactions in heterogeneous media such as biocompatible nanoporous or microporous structured materials (e.g. silica, titania, alumina) since such media could, in principle, provide an exquisite level of sensor sensitivity as they provide high surface areas for increased attachment density of receptors, and the surface energy and pore sizes can be manipulated to provide selective adsorption. The research will involve the use of microwave and optical techniques to interrogate microporous structured materials integrated into sensors.
Prerequisite: An interest in obtaining experience in electronic and optical instrumentation development, as well as working in a multidisciplinary research environment.

14) (A. Knoesen) Imaging based on Sum-frequency Spectroscopy. (top)

Orientation of molecules at interfaces has gained much attention for a variety of problems ranging from surface contact problems such as friction and adhesion, to alignment of molecules on surfaces such as anchoring of liquid crystals at interfaces. To non-destructively identify the molecules at an interface, as well as determine their orientation and location, we are developing new optical imaging techniques that are based on nonlinear optical effects present at interfaces. The challenge resides in developing instrumentation to position the sample, steer optical beams in the visible and infrared, and detect photons with great sensitivity. The research will involve the design and testing of new experimental concepts and the experimental investigation of spectra and orientation of molecules at interfaces.
Prerequisite: An interest in obtaining experience in electronic and optical instrumentation development, as well as working in a multidisciplinary research environment.

15) (T. Kuhl) Biosensing Membranes. (top)

Up to 30% of the human genome encodes proteins that reside in or interact with the cell membrane. These proteins comprise more than 50% of existing drug targets. The objective of this project is to investigate the use of self-assembled supported lipid bilayers, polymer thin-films, photolithography, and nanoscale manipulation techniques to make rapidly fabricated arrays for protein functional assays including drug discovery and binding/interaction identification

16) (M. Longo) Biomembrane Materials. (top)

The major components of biological membranes (lipids) make biomedically useful nanometer-scale structures which will be explored in this project. For example, lipids self-assemble into: monolayers at an air-water interface, bilayers/vesicles in water, and supported bilayers on surfaces. The student will learn how to make the structure (e.g. vesicle), perform physical measurements (e.g. mechanical properties) on the structure, and relate the measurements to a biomedically useful property (e.g. effectiveness in stabilizing the structure for drug delivery). These will be part of the ongoing effort in the Longo laboratory: http://www.chms.ucdavis.edu/research/web/longo/.

Replication of increasingly smaller features via photolithography has been the driving force behind advances in microelectronics. The controlled creation of nanometer-sized features has also become increasingly important in other technology areas (biotechnology, data storage, displays, etc.). We are currently examining alternatives to photolithography via contact methods for the massive reproduction of sub-micron features (i.e. contact molding and embossing). We have been developing new methods for molding functional features. A key advance has been the exploitation of functionalized surfaces which after molding, can be subjected to a number of secondary reactions allowing unprecedented control of both size and the chemistry of replicated nanofeatures. This project will involve the design, synthesis, and characterization of new materials and surface functionalization of these patterned surfaces to create new technologically interesting materials.
Prerequisite: Must be a biochemistry, chemistry, chemical eng. or materials science major. Preference will be given to 3rd and 4th year students showing great interest and enthusiasm in the field.

18) (J. Frommer) The Behavior of Ultrathin Polymer Films in Confined Spaces. (top)

As organic films scale down to ultrathin dimensions, how do they behave? How do the physical properties of polymers in a flask and polymers on a surface compare? Films less than 1micron in thickness are now appearing frequently in research labs. Their presence is also increasing in product applications, yet at these dimensions the population of molecules is limited and their environment is not homogeneous. We are studying the response of polymer chains as they are confined within submicron feature sizes. The methods we use include lithographic techniques to create small domains, atomic force microscopy to probe localized features and properties, and custom synthesis to intentionally alter film properties.
Prerequisite: Must be comfortable handling chemicals and instrumentation.

The fundamental changes in the properties of materials confined to nanoscopic dimensions coupled with the novel applications that are emerging have led to an explosive growth of research in this area. Nanoscopic materials have the potential to impact many different aspects of society ranging from in vivo sensors to ultra-high density storage devices, on-chip separations devices, and ultra-thin, high resolution, flexible displays. Self-assembling polymeric materials, in particular block copolymers, will play a key role in this rapidly growing field. Harnessing the chemistry, physics and engineering of polymeric materials to generate isolated nanoparticles or to direct the self-assembly of arrays of these nanostructures is essential for any future application. The goal of this program is to integrate the synthesis of novel block copolymers, the surface and interfacial physics of polymers, and the processing of thin films to control crosslinking, degradation and uniformity of the thin films.
Prerequisite: Chemistry major preferred.

20) (C. Hawker) Nanoparticles for Drug Delivery Applications. (top)

The scientific mission of this project is to develop new synthetic approaches and characterization techniques for the preparation and study of well-defined, molecular based objects. Core-shell nanoparticles will be prepared using chemistries pioneered in this lab and the assembly and manipulation of these shell crosslinked nanostructures as templates for the fabrication of nanowires, chemical or enzymatic degradation to give hollow nanocapsules for molecular sequestration and delivery will be key features of these efforts. A more fundamental challenge will be to develop an understanding of the relationship between structure, property and function for individual nanostructures or small assemblies thereof based on the rigidity and functionality of the crosslinked shell.
Prerequisite: Chemistry major preferred.

21) (J. Hedrick) Organic Catalysis: A New and Broadly Useful Strategy for Living Polymerization. (top)

Advances in organometallic chemistry in the design and synthesis of single-site metal catalysts for olefin, ring-opening metathesis, and ring-opening polymerization techniques have enabled the preparation of well-defined functional polymeric materials with predictable molecular weights and narrow polydispersities. Surprisingly, relatively few polymerization reactions have been reported which employ simple organic molecules as reaction catalyst, despite the widespread availability of organic chemicals in enantiopure form. The ring-opening polymerization (ROP) of lactides, lactones and epoxides using nucleophilic organic catalysts such as amines, thiophenes, phosphines and imidizolidine carbenes has been investigated. The strategy employed for the ROP using organic catalysts is as follows. First, a nucleophile such as an alcohol must be used to initiate the polymerization of the cyclic monomer in the presence of the catalyst, which provides a means of molecular weight and end-group functionality control. Secondly, the ROP does not evolve a co-product and since the equilibrium is enthalpically driven, the equilibrium is prejudiced towards polymerization. Mild and highly selective polymerization conditions either in bulk or solution produced polymers with predictable molecular weights and extremely narrow polydispersities. New strategies for chiral and "planar-chiral" organocatalysts that enable the formation of highly enantioselective poly(lactides) and polyethers from racemic monomer mixtures will also be developed.
Prerequisite: Must be a chemistry major.

22) (J. Hedrick) Novel Macromolecular Architectures Based on Biocompatible Aliphatic Polyesters. (top)

Macromolecular engineering has assumed increasing importance in polymer science. One approach to complex molecular architectures is through the preparation of block copolymers or two distinctive homopolymers covalently bound at one point. Another approach to complex molecular architectures is the introduction of controlled branching. The use of ring-opening polymerization (ROP) methods to develop such new architectures has been much less pervasive than other synthetic techniques. Our interest is in the ROP of lactones, lactides, etc. and other related monomers. This project will involve the synthesis of new biocompatible polymers with the object of tailoring elastomeric mechanical properties with new molecular architectures.
Prerequisite: Must be a chemistry major.

23) (R. Miller) Porosity in Thin Films: Generation, Characterization and Applications. (top)

The generation of porous thin films where the porosity is uniformly distributed is a difficult task which we accomplish using thermally sacrificial macromolecular porogens (pore generators). These materials are prepared by a variety of controlled polymerization techniques that lead to control of polymer properties and architectures. When porogens are added to an appropriate thermosetting matrix they become dispersed in the matrix and can be burned off to leave behind holes. Thin porous films have a variety of applications depending on the pore sizes and morphologies. Samples with hydrophobic, nanoscopic closed-cell porosities are applicable for ultra-low k on-chip dielectric applications. On the other hand, large interconnected, hydrophilic pores provide bioscience applications as high density, 3D substrates for biochips and sensors. We are interested in both applications and are studying the utilization of sacrificial porogen approaches. The project is multidisciplinary requiring interactions with a diverse team providing expertise in polymer synthesis, processing, characterization, patterning, surface modification, functional attachment and analysis.
Prerequisite: Must be a chemistry or chemical engineering major.

23.5) (W. Swope) Protein folding -- Simulation and Analysis. (top)

Understanding the underlying design principles of protein folding will have major impact not just on biology and the life sciences but also on our ability to design similar nanostructured polymers. One open question in protein folding is the role of entropy in the overall stability of the folded state. Preliminary analysis of folding simulations suggests that the folded state is differentiated from other compact states of the protein not by energy (i.e. there are compact states with the same favorable energy as the folded state) but by entropy (the folded state consists of many such low-energy structures, while low-energy but nonnative structures are few in number). This project will analyze some of the large protein simulation data sets to study the role of entropy in stabilizing the folded states of proteins. In particular, we will examine the degree of disorder of the protein backbone and side chains and see how this contributes to the observed entropy of the folded state. From these observations, we will aim to extract general principles that can be used to guide the design of other nanostructured polymers.
Prerequisite: An interest in life sciences, computer simulation of biological molecules, or statistical mechanics and some basic computer programming skills.

We have a broad charter in our group in the areas of microfluidics and biomolecular sensors. We have very active programs involving "surface-related" issues in both areas. In the area of biosensors, for example, we are modifying nanoparticles with self-assembled monolayers for biomolecular attachment. We also modify the surfaces of substrates (especial glass-slides) so the nanoparticles bind specifically to complementary functional groups patterned on the glass. Detection of the particles involves photocatalysis as well as fluorescence and light scattering. We are in the process of expanding this effort through a collaborative research agreement with IBM Almaden in this area. Another biosensor project involves sensing "non-labeled" biomolecules using microwave waveguides. We are collaborating with UC Davis (Andre Knoesen) and IBM-Almaden (Bob Miller) in designing new instrumentation and creating unique surfaces to enhance the sensitivity of the measuremens. We plan to investigate biologically relevant protein-protein interactions in "real time" using this approach. We also have a project involving methanol fuel-cells, and several projects in microfluidics for chemical and biochemical analysis. We encourage applicants to contact us (e-mail daniel_roitman@agilent.com or by phone 650-485-5958) if they would like to hear more about the projects or to discuss their possible participation on any of these projects. We plan to integrate SURE students with all the activities offered to all other Summer Agilent Interns.

Ultra thin, polymeric films synthesized in a plasma assisted deposition process offer unique properties as biomaterial coatings for metallic or polymeric devices, sensors and implants. Using a modulated 13.56 MHz rf discharge it is possible to tailor the functional group density and the macromolecular architecture and thus significantly influence the physical, chemical and biological properties of these films. We are actively investigating the relationship between the plasma polymerization conditions, the polymer film structure and the reactivity of the films towards biological molecules. Of particular interest are films synthesized from maleic anhydride, which have in the past shown to be excellent candidates as supports for lipid bilayers. Their success as biomaterial coatings appears to be due to their ability to convert into polyelectrolyte-like films when immersed in aq. solution. In order to further our understanding of the reactions at the interface, we would like to carry out a number of surface derivatization reactions utilizing small molecular analogues to investigate the effects of different pH and ionic strength environments. The project will involve the preparation of substrates and the deposition of nanometer thin plasma polymer films using our existing pulsed rf plasma deposition system. The plasma polymer films will then be exposed to basic wet chemical derivatization reactions and the reactions will be monitored using Fourier Transform Infra Red Spectroscopy and contact angle goniometry. To monitor the effect of pH and ionic strength on the reactivity of the surface the potential candidate will be introduced to more specialized analytical techniques such as Surface Plasmon Resonance Spectroscopy and Electrochemistry.
Prerequisite: Must be a chemistry or chemical engineering major.

26) (C. Thielemann) UV-based Patterning of Polymeric Substrates for Cell Culture Applications. (top)

We plan to study the physico/chemical effects of deep UV irradiation of polystyrene and polymethylmethacrylate (PMMA) with respect to cell adhesion in vitro. The exposure of polymer surfaces to ultra violet light of short lengths alters the physical behavior and chemical composition of polymer surfaces. Irradiated surfaces of polystyrene and PMMA become hydrophilic and unstable peroxides together with stable carboxylic groups are formed. We expect that neuronal cells exhibit strong adhesion on the irradiated surfaces while unmodified surfaces stay cell repellent. Masked irradiations could open a simple way to obtain chemically patterned polymeric substrates for structured cell adhesion. In our case the technique will be useful for the patterning of neuronal networks.
Prerequisite: Must have an interest to work on an interdiscipinary project at the border between biology and surface chemistry.

The project is connected to development of functional solid substrates for the high throughput measurements and control of interactions with biomolecules and cells: 1) fabrication of polymer film with composition gradient of the mixed polymer brush (tethered chains of two different polymers randomly grafted to the same substrate, for example PP and PEG, in such a fashion that the layer has a smooth gradient of the composition in x-direction); 2) study of adsorption of biologically active materials (DNA, proteins, cells) on the film surface with ellipsometry and atomic force microscopy. We would like to develop a fast method of separation and analysis of biomolecules and control their interactions with functional surfaces. At the same time we perform a combinatorial screening for search of biocompatible surfaces.
Prerequisite: Polymer science, physical chemistry, interest in biopolymers.

28) (M. Stamm) Polymer Films from Mixed Brushes. (top)

Utilizing scanning force microscopy we can visualize the chain conformation of single polymer molecules, which are adsorbed and immobilized at a solid substrate. We want to use this technique to learn about details of the chain conformation and to study effects of phase transitions and external fields (shear, electric field) on the nano-structure at the surface. It thus should be possible to understand the properties of polyelectrolytes in aqueous solutions much better, which will help for their dedicated use in various areas.
Prerequisite: Polymer science, physical chemistry.

29) (B. Voit) Functional Polymers for Integration Tethered Lipid Bilayers on Solid Surfaces. (top)

Phospholipid bilayers are of scientific importance due to their potential to act as models for natural membranes controlling the processes in cells and thus, to their potential in studying membrane bound biomolecules and biological processes. For these studies it is necessary to attach lipid bilayers on solid surfaces in such a way that mobility of the membrane and a physiologically similar surrounding can be obtained. An attractive approach is the preparation of tethered lipid bilayers having a polar, flexible cushion between the solid substrate and the lipid layer. This cushion can control the amount of water underneath the lipid layer as well as the distance between lipid and solid substrate. Up to now it has not been clear what nature of the cushion will be most favorable for preparing stable lipid bilayers which can integrate different membrane proteins. Therefore, we would like to design new functional polymers with a high potential for variation and thus optimization. For this, we will prepare new telechelic polar polymers prepared by a living polymerization method having functional units for covalent attachment to the solid surface and a lipid-like chain end which can be incorporated into the lipid bilayer. By an initiating/endcapping process, these two different functionalities have to be incorporated at the polymer chain ends and the living polymerization process allows variation in the length of the polymer chain and therefore the distance between bilayer and substrate. The resulting polymers will be attached to a solid surface and surface, and the structure of the polymer chains as well as the surface properties will be studied by different techniques e.g. FT-ATR-IR, ellipsometry, AFM and contact angle measurements. First interactions between lipids and the lipid chain ends of the macromolecules will be observed.
Prerequisite: Chemistry major is preferred. Must have experience in organic chemistry and/or polymer chemistry and must be comfortable in handling chemicals and instrumentation

30) (B. Voit) Biocompatible Surfaces Based on Dendritic Structures. (top)

Dendritic polymers, so-called dendrimers, as well as the less defined hyperbranched polymers, have attracted much interest in recent years. Their compact, branched structure combined with high functionality and interesting properties started the discussion on using them in classical polymer applications such as coating formulation or in blend systems, but also as polymeric functional layers in coatings and in pharmaceutical and medical applications. The capability of dendritic molecules attached to solid surfaces to act as biocompatible or even bioactive organic layers is still not explored. We would like to prepare new dendritic molecules having amide linkages which can be attached by different processes to a solid surface. End groups at the branched chain ends will be varied from bioinert to bioactive and the interaction of surfaces covered by these molecules with biological molecules like proteins will be studied. Surface properties of organic materials govern nearly exclusively their hemocompatibility or interaction with tissue. A very low interaction with blood components is needed for many medical products. In contrast, a high interaction of the organic surface, which favors selective cell growth and allows the release of biological active components e.g. growth factors, is the basic prerequisite for successful tissue engineering approaches.
Prerequisite: Chemistry or biochemistry major is preferred. Must have experience in organic chemistry and/or polymer chemistry and must be comfortable in handling chemicals and instrumentation.