Microbial Transglutaminase and Tyrosinase Modified Gelatin-Chitosan Material

A dual-enzymatically modified protein-polysaccharide, which is a potential biomaterial especially for biomedical film, is constructed, modified and reinforced entirely by biocompatible and environmentally-friendly biomacromolecules. We use gelatin/chitosan blend as protein-polysaccharide matrix, and then employ microbial transglutaminase and tyrosinase as biological modifiers. The subsequent tests indicated that the stability in aqueous medium, thermal stability, and tensile strength of the modified material have been improved due to the combined effects of two enzymes that microbial transglutaminase can cross-link gelatin and tyrosinase can catalyze gelatin-chitosan conjugation. Furthermore, the modified gelatin-chitosan shows better in vitro antibacterial activity in comparison with unmodified gelatin.