In vitro and in vivo investigational studies of a nanocomposite‐hydrogel‐based dressing with a silver‐coated chitosan wafer for full‐thickness skin wounds

A nanocomposite reservoir‐type hydrogel dressing of poly vinyl alcohol (PVA) was fabricated by a freeze–thaw method and loaded with silver‐nanoparticle‐coated chitosan wafers (Ag–CHWs). The Ag–CHWs were synthesized by a sonication technique with silver nitrate (AgNO₃) and chitosan powder. Scanning electron microscopy images showed silver nanoparticles (AgNPs) with a size range of 10 ± 4 nm on the surface of the chitosan wafers, and the antibacterial efficacy (minimum inhibitory concentration) of the Ag–CHWs was measured against Pseudomonas aeruginosa (32 µg/mL), Staphylococcus aureus, (30 µg/mL) and Escherichia coli (32 µg/mL). The antimicrobial PVA hydrogel showed an improved tensile strength (～0.28 MPa) and gel content (～92%) in comparison with the blank hydrogels. Full‐thickness‐excision wound studies of the nanocomposite dressing on Wistar rats revealed enhanced wound contraction, improved inflammation response, re‐epithelization rate, neoangiogenesis, and granulation tissue formation in comparison to the control group. A flexible, biocompatible, nanocomposite reservoir dressing not only established the chitosan as a stabilizer but also proved the efficacious and safe utility of AgNPs toward chronic wound management. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43472.