Photocrosslinked methacrylated carboxymethyl chitin hydrogels with tunable degradation and mechanical behavior.

Photocrosslinked hydrogels are being investigated for many tissue engineering applications because of the ability to form these materials in-situ in a minimally invasive manner by injection of aqueous solution under physiological conditions. In this work, carboxymethyl chitin (CMCH) synthesized homogenously was further modified with methacrylic anhydride and photocrosslinked into hydrogel with tunable degradation and mechanical properties. This new methacrylated carboxymethyl chitin (Me-CMCH) hydrogel formed in-situ photocrosslinked under UV irradiation showed much higher storage modulus than that of the thermosensitive in-situ forming physical-crosslinking CMCH hydrogel. The Me-CMCH hydrogels remained stable under physiological conditions and could be degraded by lysozyme. Cytotoxicity test indicated that the photo-induced Me-CMCH hydrogels were non-cytotoxic. The mechanical property, morphology, swelling and biodegradation behavior of the Me-CMCH hydrogels could be tuned by controlling the degree of methacrylation of Me-CMCH. These biodegradable photocrosslinkable Me-CMCH hydrogels may hold great promises for various biomedical applications.