VINSE COLLOQUIUM SERIES
Dr. Yadong Wang
William Kepler Whiteford Professor in Bioengineering
University of Pittsburgh
Host: Hak Joon Sung
“Design Biomaterials For In Situ Tissue Engineering”
4:10 PM, 5326 Stevenson Center
3:45 refreshments 5326 Stevenson Center Hallway
Abstract: In situ tissue engineering is more translatable than cell-based approaches. However, there are many challenges including host cell recruitment, foreign material associated inflammation, and synthesis of tissue-specific extracellular matrix (ECM). To address the challenges of cell recruitment and immune modulation, we designed a series of cationic polymers specifically for controlled release of growth factors. The cations and heparin self-assemble into coacervates, thereby protecting the activities of the growth factor by virtues of heparin and phase separation. We have used these coacervates to modulate inflammation and promote angiogenesis in vivo. To address the challenge of ECM synthesis, we designed porous scaffolds made of the elastomeric poly(glycerol sebacate). The nature of this material allows transmission of mechanical forces generated physiologically to the cells residing within the scaffolds. We use these scaffolds for in situ tissue regeneration of artery. The arterial scaffolds were used to replace a segment of abdominal aorta in rats. The graft materials were mostly degraded within 3 months; in its place was a neo-artery that mimicked native artery mechanically, biochemically, and anatomically. The neo-arteries were well integrated with the host, remained patent and pulsed synchronously with host arteries at one year. Furthermore, perivascular nerves were also regenerated. This study indicates that synthetic polymers can induce tissue regeneration in mammalian hosts in situ and specifically designed biomaterials can preserve the functions of proteins effectively to induce desired cellular responses. It remains to be seen if this is translatable to large animals and humans.