In-situ photo-assisted deposition of silver particles on hydrogel fibers for antibacterial applications.

Silver nanoparticles (AgNPs) have attracted intensive research interest and have been recently incorporated in polymers, medical devices, hydrogels and burn dressings to control the proliferation of microorganisms. In this study a novel silver antibacterial coating was deposited for the first time on hydrogel fibers through an in-situ photo-chemical reaction. Hydrogel blends obtained by mixing different percentages of silver-treated and untreated fibers were characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Four different fluids, such as phosphate buffered saline (PBS), simulated body fluid (SBF), chemical simulated wound fluid (cSWF), and deionized water (DI water), were used for evaluating the swelling properties. The results obtained confirmed that the presence of silver did not affect the properties of the hydrogel. Moreover, the results obtained through inductively coupled plasma mass spectrometry (ICP-MS) demonstrated very low silver release values, thus indicating the perfect adhesion of the silver coating to the substrate. Good antibacterial capabilities were demonstrated by any hydrogel blend on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) through agar diffusion tests and optical density readings.