Bioinspired design of AgNPs embedded silk sericin-based sponges for efficiently combating bacteria and promoting wound healing

A wound dressing with excellent hydrophilicity, high porosity, good mechanical property, and antimicrobial activities holds great potential for wound healing. Sericin, a natural protein from silkworm cocoon, is particularly attractive for the development of skin-repairing materials because it is biocompatible and biodegradable. Here, we reported a green strategy for in situ biomimetic synthesis of silver nanoparticles (AgNPs) within sericin/poly(vinyl alcohol) hydrogel. AgNPs were in situ synthesized by the redox property of tyrosine residues in sericin without additional chemicals, similar to a biomineralization process. AgNPs-sericin/poly(vinyl alcohol) dressing was demonstrated to bear desired high porosity, good wettability, hygroscopicity, and mechanical properties. The evaluation of cytocompatibility and immunotoxicity of the composite with NIH/3T3, HEK-293, and RAW264.7 cells further demonstrated its excellent biocompatibility. The composite also showed an effective antibacterial activity against Staphylococcus aureus , Escherichia coli , and Pseudomonas aeruginosa , and could inhibit biofilm formation caused by Staphylococcus aureus and Pseudomonas aeruginosa . Finally, the animal experiment suggested that the composite dressing could facilitate re-epithelialization and collagen deposition to promote wound healing. Our work shows that the composite dressing has great potential as a competitive alternative for traditional wound dressings.