Development of responsive chitosan-based hydrogels for the treatment of pathogen-induced skin infections.

Vancomycin (Van) remains one of the first-line drugs for the treatment of wound infections caused by methicillin-resistant Staphylococcus aureus (MRSA). However, the unsatisfactory bioavailability of vancomycin alone has greatly limited its potential health benefits. Here a responsive chitosan-based hydrogel was developed as the delivery system which not only would reduce this side effect but also increase efficacy of vancomycin. The hydrogel was prepared by grafting chitosan and cinnamaldehyde-based thioacetal (CTA) together with ginipin (G) as the crosslinker. Upon exposure to reactive oxygen species which were enriched in the bacterial wound, the hydrogel can locally degrade and sustainably release the loaded vancomycin near the lesion to compete with the troubling MRSA. Compared with vancomycin alone, the chitosan-based hydrogel loaded with vancomycin demonstrated accelerated acute wound healing. This achievement reveals that this multi-functional hydrogel may be a promising drug-delivery device for improving the efficacy of local antibiotic therapy.