SCIENCE AT THE EDGE SEMINAR
http://www.pa.msu.edu/seminars/edge


11:30 a.m., Friday, November 15, 2002
Room 1400 Biomedical and Physical Sciences Building
Refreshments at 11:15 in Room 1400A BPS


Speaker:  Peter X. Ma
          University of Michigan
          Ann Arbor, MI

Title:    Materials Science Tricks for Tissue Repair

Abstract:

Our group uses materials science tricks to develop scaffolds (synthetic
temporary extracellular matrices) for tissue repair. We design synthetic
biodegradable polymer scaffolds on which cells adhere, proliferate,
differentiate, and regenerate 3-D tissues. While the new tissue is
developing, the polymer scaffolds degrade and resorb, leaving nothing
foreign in the body. We mimic certain advantageous aspects of natural
extracellular matrices, and impart certain desired features with synthetic
material design. Following are a few examples to demonstrate this biomimetic
approach undertaken in our laboratory. (1) To mimic bone matrix,
biodegradable polymer/bioceramic composite scaffolds are developed. The
experimental data show that they serve as osteoconductive scaffolds and
advantageously support mineralized tissue regeneration. (2) To mimic the
architectural organization of fibrillar and tubular tissues (such as nerve,
muscle, tendon, ligament, blood vessel, bone and teeth), directional crystal
growth techniques have been developed in our laboratory to create a parallel
array of micro tubules from biodegradable polymers. Cells respond to the
architectural features in terms of neo tissue organization. (3) Collagen is
a major extracellular protein in nearly every body part, and has a fibrous
structure with a fiber diameter usually ranging from 50 to 500 nanometers.
To mimic the nano-fibrous architecture and to overcome the concerns of
immune rejection and disease transmission associated with collagen from a
natural source, synthetic nano-fibrous scaffolds have been developed in our
laboratory using a novel phase-separation trick. (4) To mimic soft tissue
such as cartilage, ionic interactions are utilized to crosslink alginate
hydrogel as scaffolds with controlled structure and properties. Our
experimental data demonstrate that biomimetic design is a powerful approach
for designing tissue engineering scaffolds.