In situ reduction of silver nanoparticles by gelatin to obtain porous silver nanoparticle/chitosan composites with enhanced antimicrobial and wound-healing activity.

The identification of materials with beneficial properties for wound healing is a major research goal. In this study, gelatin was used as a reducing agent and stabilizer to restore silver nanoparticles (AgNPs) in situ, which were mixed with chitosan (CS), crosslinked with tannic acid, and then freeze-dried to obtain a new composite Gelatin/CS/Ag. Gelatin/CS/Ag has a dense pore structure with a pore size of about 100-250 μm. The pores were interconnected. The existence of AgNPs was proven by UV visible spectrophotometry, XRD, and electron microscopy. Gelatin/CS/Ag exhibited good mechanical properties, water absorption, and moisture retention. The material was evaluated in antibacterial experiments, and a good inhibitory effect of Gelatin/CS/Ag was observed. Gelatin/CS/Ag co-cultured with L929 cells did not show cytotoxicity. Finally, Gelatin/CS/Ag promoted wound healing and showed good biocompatibility. In summary, Gelatin/CS/Ag has promising antibacterial and wound healing properties.