Evaluation of strategies to incorporate silver nanoparticles into electrospun microfibers for the preparation of wound dressings and their antimicrobial activity

Currently, wound dressing technology is of significant interest in order to avoid undesired effects when burns or skin wounds are treated, especially their risk for microbial contamination and subsequent infection. Silver nanoparticles (AgNPs) have claimed importance as antimicrobial agents. For these reasons, a comparative study of different methods to synthesize electrospun polymeric fibers loaded with AgNPs (Ag+/PCLPVP) such as direct blending, ultraviolet irradiation, thermal treatment, and silver mirror reaction methods were done. The morphology and size of the fibers were investigated using the SEM, where the loading of the AgNPs in the fibers was measured with EDS analysis. FTIR, Raman spectroscopy, XRD, and TGA analysis were applied to measure the physicochemical properties of the fibers. DLS study allowed us to measure the size and surface charge of the obtained materials. The antimicrobial efficiency was carried out against Staphylococcus aureus and Escherichia coli bacteria for 24 h. Cytotoxicity was evaluated with the MTT assay using HFF1 cells. The results showed that the method with the best antimicrobial effect in both bacteria is the UV irradiation conducted before the electrospinning process. The UV radiation method also promotes good distribution efficiency, the physicochemical properties obtained were desirable for wound dressings, and the particle size within nanoparticle interval (similar to 17 nm). Therefore, the most promising method for the preparation of Ag+/PCLPVPbased wound dressings was UV irradiation.