Cytotoxicity and genotoxicity studies of silver ions and various silver nanoparticles on multiple cell types in vitro on the basis of wound healing

Silver has been used for centuries for its antimicrobial and wound healing properties. Although the mechanism of antibacterial effect was almost clarified, the wound healing effect is still not clearly understood. In this study, the effects of silver ions (Ag+) and silver nanoparticles (AgNP) on wound healing were comparatively investigated in vitro. In order to shed a light on the mechanism, the cytotoxic and genotoxic effects of (Ag+) and various AgNPs, which were synthesized with different reducing agents; AgNP-C (citrate-reduced silver nanoparticle), AgNP-M (maltose-reduced silver nanoparticle), AgNP-L (lactose-reduced silver nanoparticle), AgNP-G (glucose-reduced silver nanoparticle), on three cell types; human dermal fibroblasts (HDF), mouse macrophages (RAW 264.7), and mouse fibroblasts (L929) were studied. MTS assay was applied to analyze the cytotoxic effects of Ag+ and AgNPs at different concentrations for variable exposure time. Besides, DNA fragmentation and annexin V-PI staining were carried out to detect DNA damage. This study suggests that the Ag+ other than the AgNPs are toxic on the living cells and therefore the dissolution of the AgNPs could be an important factor since the AgNPs act as a supplier for Ag+. As a conclusion, a relationship between the toxic effect of silver and the wound healing was established using Ag+ and AgNPs. It was observed that, under the same conditions, AgNPs showed similar proliferative effect with Ag+ and less toxic effect than Ag+.