UCLA

The thesis includes two parts: (1) fabrication of kink-resistant polycarbonate-urethane (PCU) nanofibrous vascular graft, and (2) surface modification and in vitro evaluation for kink-resistant polycarbonate-urethane (PCU) nanofibrous vascular graft.

Cell and tissue engineering with regenerative medicine is a rapidly growing field that combines knowledge and technology from fields such as biology, engineering, materials, chemistry, mechanics, and medicine. The current arterial replacement is one of the most common treatments for cardiovascular disease. However, the implanted grafts are usually failed because of the formation of thrombosis and neointimal hyperplasia, due to its poor blood compatibility and mechanical mismatch.

In this thesis, we developed a desired vascular graft with enhanced mechanical�properties and�biocompatibility by engineering biomaterials. In the first part, we developed the kink-resistant nanofibrous vascular graft by electrospinning combined with spiral coil integration techniques. We indicated that our newly designed kink-resistant grafts can maintain the lumen better than normal vascular grafts to keep the patency after implantation. In the second part, we investigated several surface amination methods and heparin conjugation techniques to endue anti-thrombosis properties for PCU grafts. It is confirmed that higher amine coating density is corresponding to the higher heparin conjugation rate. Furthermore, PEG and PEG/Heparin treated substrates showed a significantly higher anti-thrombogenic activity and provided the cells with a more suitable growth environment.

Taken together, this research provides a possible solution to avoid the kink and banding of the electrospun vascular graft with anti-thrombogenic effects.