Silver nanoparticle-embedded poly(vinyl pyrrolidone) hydrogel dressing: gamma-ray synthesis and biological evaluation

Silver nanoparticle (nAg)-embedded poly(vinyl pyrrolidone) (PVP) hydrogels, to be used as antibacterial wound dressings, were prepared by γ-irradiation at various doses: 25, 35, and 45 kGy. The formation and characteristics of the silver nanoparticles were investigated with a UV-vis spectrophotometer, transmission electron microscopy, and scanning electron microscopy with energy-dispersive X-ray. The hydrogels were characterized for physical and biological properties. Based on the antibacterial determination, the 1 and 5 mM nAg-embedded PVP hydrogels were effective, with 99.99% bactericidal activity at 12 and 6 h, respectively. The indirect cytotoxicity evaluation based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay indicated that both the neat and the nAg-embedded PVP hydrogels were non-toxic to mouse fibroblasts (L929). The 5 mM nAg-embedded PVP hydrogels not only provided a clean, moist environment for wound healing, but also effectively prevented bacterial infection and enhanced wound recovery.