Regulation of the Degradation Properties of Tyrosinase-Catalyzed Crosslinking Silk Membranes for Superficial Wound Repair

Appropriate biodegradability to meet the demands of wound repair is critical for superficial wound repair membrane applications. Tyrosinase-catalyzed crosslinking SF (c-SF) membranes were constructed and regulated the degradation behavior in this study. The crosslinking degree of the c-SF membranes could be adjusted by reaction ratios of tyrosinase against SF (TYR/SF). Upon reaching a TYR/SF ratio of 20/6000, the degree of crosslinking increased to 88.17 +/- 0.20%, without obvious changes in the crystal structure. The degradation behavior was regulated by the TYR/SF ratio and the degradation environment. All c-SF membranes remained stable after immersion without collagenase but showed an adjustable degradation behavior in the presence of collagenase. As the TYR/SF ratio increased, the residual weights increased from 23.31 +/- 1.35% to 60.12 +/- 0.82% after 7 days of degradation, occurring with low increased amounts of beta-sheet structure and free amino acids. This work provides a new c-SF membrane with controllable rapid degradability and favorable cytocompatibility, which can help to meet requirements for biodegradable superficial wound repair membranes.