Silver/poly(vinyl alcohol)/chitosan/graphene hydrogels - Synthesis, biological and physicochemical properties and silver release kinetics

This study presents the synthesis of novel silver/poly(vinyl alcohol)/chitosan/graphene (Ag/PVA/CHI/Gr) nanocomposite hydrogels by in situ electrochemical reduction of silver ions in the hydrogel matrix and their thorough characterization by UV-visible and Raman spectroscopies, field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and silver release measurements. The influence of chitosan content on the incorporation and stabilization of silver nanoparticles (AgNPs) was investigated, and we found that hydrogels with higher chitosan content contain higher amounts of AgNPs. In addition, the cytotoxicity and antibacterial activity of Ag/PVA/CHI/Gr nanocomposite hydrogels were evaluated. Based on in vitro investigations, the obtained materials exhibit diffusion-controlled release profiles over 28 days, strong antibacterial activity against Staphylococcus aureus and Escherichia coli bacterial strains, and no cytotoxicity toward human and mice fibroblast cell lines.