The International Research and Education in Engineering (IREE) award sponsored by the National Science Foundation (NSF) and organized by Purdue University facilitates the travel and research of a BS/MS student from Drexel University's School of Biomedical Engineering to Shanghai, P.R. China for approximately three months. The purpose of conducting the project in China was to continue an already established relationship with the Shanghai Key Tissue Engineering Laboratory and conduct novel research, which combines the expertise from each laboratory; home institution's expertise in polymer biomaterials and drug delivery and the host institution's expertise in cell culture and tissue engineering. Cartilage damage continues to be one of the complex challenges in orthopedic medicine. Current biomaterial solutions have been had limited success in repairing or regenerating healthy cartilage tissue. These failures are due to poor mechanical strength and poor integration with surrounding tissues. Utilizing a controlled release system of a growth factor characteristically shown in cartilage development, within a non-degradable scaffold, offers better immediate support with enhanced and directed cellular in-growth. In this study, IGF-1 was encapsulated in degradable poly(lactic-co-glycolic acid) (PLGA) microparticles embedded in non-degradable poly(vinyl alcohol) (PVA) hydrogels in one-step by a double emulsion technique. Hydrogels were characterized to have optimal mechanical properties to support a cartilage defect and porosity in order to allow cell penetration into the hydrogel. The release of IGF-1 was maintained for two weeks and five weeks in vivo. Hydrogels were directly seeded with auricular rabbit chondrocytes and implanted subcutaneously into nude mice. Cartilage was observed in the cell-seeded sample groups containing IGF-1 and not containing IGF-1. The release of IGF-1 yielded an increase in cartilage formation as shown with biochemical, mechanical, and genetic expression. The controlled release of IGF-1 with the increased porosity shows enhanced cartilage formation and integration into the hydrogel.

Claire Martin is an undergraduate student pursuing a BS/MS in Biomedical Engineering at Drexel University. She was supported by IREE to perform research at Shanghai Jiao Tong University. Her self-placement continued a relationship between Shanghai Key Tissue Engineering Laboratory and Drexel's Biomaterial and Drug Delivery Laboratory, bringing together her home institution's expertise in polymer biomaterials and drug delivery and the host institution's expertise in cell culture and tissue engineering.

Researchers should cite this work as follows:

• Claire E Martin (2011), "Semi-Degradable Porous Hydrogels for Controlled Release of IGF-1 for Cartilage Engineering," http://globalhub.org/resources/4747.

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2. iree trip report 6