Department of Materials Science and Engineering
University of Delaware
201 DuPont Hall
Newark, DE 19716-3106
Phone: (302) 831-6553
Fax: (302) 831-4545
Ph.D. Polymer Science and Engineering, University of Massachusetts Amherst, 2002
M.S. Polymer Science and Engineering, University of Massachusetts Amherst, 1999
M.S. Polymer Chemistry and Physics, Fudan University, China, 1998
B.S. Applied Chemistry, Fudan University, China, 1995
Our current research program is divided into three specific areas. The first area aims at engineering artificial extracellular matrices (ECM) that are not only reconfigurable and adaptable, but also exhibit desired mechanical properties that are conductive to tissue growth. Several synergistic approaches are being undertaken to achieve this goal. To mimic the inherently dynamic characteristics of the natural ECM, we are synthesizing mechano-responsive polymeric matrices by utilizing specific and reversible non-covalent interactions as cross-linking motifs. The ability of systematically varying the matrix mechanical properties is likely to offer handles for the determination of cell behaviors. To mimic the multifunctional nature of the amorphous components of the natural ECM, we are developing hyaluronic acid-based hydrogel particles with controlled size, hierarchical structure and tunable viscoelasticity as injectable materials for use in wound healing, adhesion prevention and soft tissue engineering. To mimic the unique biological and mechanical properties of the natural ECM, we are designing hybrid polymers with alternating multi-block architecture composed of flexible synthetic polymer segments and self-assembling peptide sequences. The hybrid polymers are expected to assemble into nanoscale architectures that recapitulate the structure and properties of native elastin.
The second research area is soft tissue engineering, with an emphasis on vocal fold tissue regeneration. We are interested in restoring the damaged vocal fold using tissue engineering methodologies. Before embarking on this challenging task, it is critical to understand the tissue itself. We are evaluating vocal fold biomechanics at both cellular and tissue levels. At the cellular level, we are exploring the effect of mechanical stimulation on vocal fold fibroblasts in terms of cell signaling, cytoskeletal organization and gene expression. At the tissue level, we are evaluating viscoelastic response of vocal fold lamina propria at frequencies of human phonation. We are also studying vocal fold ultrastructure from molecular level up to macroscopic scale. This knowledge will be applied to the design of functional vocal fold substitute materials. In vitro functional tissue formation will be accomplished by the appropriate combination of artificial scaffolds, biological cues and mechanical stimuli.
The final aspect of our research activities involves the application of surface engineering methodology to create functional biointerfaces. Most polymeric implants currently used cause biological encapsulation and foreign body reaction that impair their performances. Ultimately, the implants have to be surgically removed in order to avoid further complications. This project emphasizes surface engineering to improve the biocompatibility of polymer implants. We are exploring a range of approaches for the fabrication of surfaces with well-defined topography at the nanometer scale. These nanostructured surfaces are interesting platforms to explore the effects of nanometer scale topography on protein adsorption, and subsequently cell behavior.