Chitin-Methacrylate: Preparation, Characterization and Hydrogel Formation

Chitin-methacrylate (CM) was prepared by the reaction of methacrylic acid on chitin in 5% LiCl/DMAc in the presence of N,N'-dicyclocarbodiimide and dimethylaminopyridine. The resultant chitin-methacrylate product was isolated in 61% yield and was found to be readily water-soluble. The derivative was found to be a mixture of methacrylate and methacrylic-dimethylaminopyridine complex substituents at the C-6 position in approximately equal amounts. In order to evaluate the activity of the methacrylate double bond, a chitin-methacrylate water solution was photo-crosslinked in the presence of Irgacure 2959 photo-initiator to generate CM-hydrogel. The CM-hydrogel was evaluated for its biodegradability characteristics by enzymatic degradation with lysozyme solutions of varying concentrations. Completely water-soluble products were obtained within 48 h. In vitro cytotoxicity assays of the CM-hydrogel and its extract against three cell lines, NCTC clone 929, IMR-90 and MG-63, indicated the hydrogel was non-cytotoxic with cells able to adhere and proliferate well on the hydrogel.