Peptide interfacial biomaterials improve endothelial cell adhesion and spreading on synthetic polyglycolic acid materials.

My research lies at the intersection of surface and colloid science, polymer materials engineering, and biointerface science, with four central areas of focus:

1. Fabrication, manipulation and characterization of stimulus-responsive biomolecular and bio-inspired polymeric nanostructures on surfaces;
2. Nanotechnology of soft-wet materials and hybrid biological/non-biological microdevices;
3. Receptor-ligand interactions relevant to the diagnostics of infectious diseases;
4. Friction of soft-wet materials, specifically the role of glycoproteins on friction in diarthroidal joints.

These four broad lines of inquiry deal with fundamental behaviors of soft-wet materials on surfaces and interfaces. The design and fabrication of these interfaces using "smart" polymeric and biomolecular nanostructures, and the characterization of the resulting structures, are critically important for the development of biomolecular sensors and devices and for bioinspired materials. Key approaches and tools I use in my research are: bottom-up organization on the molecular scale, through self-assembly, in-situ polymerization, and manipulation of intermolecular interactions; topdown fabrication, through scanning probe nanolithography; stimulus-responsive polymers; molecular recognition; and new approaches to sensing and manipulation. This research supports Duke's Pratt School of Engineering strategic initiative to expand research in soft-wet Materials Science.

Our overriding interests are in the fields of tissue engineering, wound healing, biosensors, and long term improvement of medical device implantation. My basic research interests are in the area of physiological mechanisms of optimizing substrate transport to tissue. This broad topic covers studies on a whole animal, whole organ, hemorheological, microvascular, cellular, ultrastructural, and molecular level. The current projects include:
1) control of blood flow and flow distribution in the microcirculation,
2) the effects of long-term synthetic and biologic implants on substrate transport to tissues,
3) tissue engineering; combining isolated cells, especially adult stem cells, with biomaterials to form specialized composite structures for implantation, with particular emphasis on endothelial cell physiology and its alteration by isolation and seeding on biomaterials.
4) decreasing the thrombogenicity of synthetic blood vessels and other blood-contacting devices, and improving their overall performance and biocompatibility.
5) reducing tissue damage resulting from abnormal perfusion (e.g., relative ischemia, anoxia, etc.) and therapies which minimize ischemic damage.
6) biosensor function, particularly glucose sensors in normal and diabetics.
7) measurement of tissue blood flow and oxygenation as an indicator of tissue viability and functional potential.
8) development of biocompatible materials for soft tissue reconstruction or augmentation.
9) improving performance of glaucoma drainage devices by directing a more favorable foreign body reaction
10) wound healing; particularly internal healing around foreign materials and the effect and prevention of microbes around implanted devices.

My research interests focus upon the effect of physical forces on the function of vascular cells and skeletal muscle, cell adhesion, and the design of engineered tissues.  Current research projects examine the  effect of endothelial cell senescence upon permeability to macromolecules and the response to fluid shear stress, the development of microphysiological blood vessels and muscles for evaluation of drug toxicity and the design of engineered endothelialized blood vessels and skeletal muscle bundles.