Abstract
The synthesis of photocrosslinked and thermosensitive hydrogels are performed by copolymerization of poly(L-alanine)(L-PA) and poly(ethylene glycol)(PEG). Both ends of PEG were conjugated with L-PA to form a PA-PEG-PA(PEA) tri-block. Then, the terminal ends of PA-PEG-PA were modified by acroyloyl groups, which was called “diacrylation”. Exposing this material to UV-light, photo-crosslinking would begin. As photoinitiator attacked C=C double bond of vinyl groups and induced photopolymerized to form the gel. First, we want to use the thermosensitive property of the tri-block to form the hydrogel, and let it expose UV to begin photocrosslinking. This step we hope can increase mechanical strength of the hydrogel. Besides, alanine is an amino acid, it is more suitable to culture cell than polyester hydrogels. We think the hydrogel we made that can increase not only strength but with good biocompatibility. In this study, we prove that PEA hydrogel can enhance cell proliferation whether cell seeded on hydrogel surface or encapsulated into hydrogel. Comparing with PEG hydrogel, PEA hydrogel has better performance on cell viability than PEG hydrogel. In addition, we study that PEA incorporated with β-TCP which is main component of bone can promote cell proliferation and also induce osteogenic differentiation. In summary, this copolymer “PEA” has wide range of the development in the tissue engineering field, such as bioadhesive, cartilage or bone regeneration.