In vitro toxicity of silver nanoparticles on murine peritoneal macrophages.

Silver nanoparticles, the new generation of antimicrobial agents, are becoming one of the progressively growing products in nanotechnology. Meanwhile, the potential side effects of these nanoparticles have not been studied thoroughly yet. Macrophages, one of the most important immune cells in innate and acquired immune responses, are a key component of the clearance mechanisms in semi-open interfaces of human body against nanosilver (nano-Ag). In this experimental study, we assessed the effect of commercial colloidal nano-Ag on murine peritoneal macrophages by MTT and nitric oxide (NO) production assay in vitro. A significant decrease in cell viability was observed for 1 ppm (part per million) to 25 ppm of nano-Ag concentrations compared to the control group (P < 0.01) after 24 h of cell culture. Also, a significant decrease in the cell viability was observed for 2-25 ppm of nano-Ag concentrations after 48-72 h, respectively (P < 0.05). In our study, exposure to 0.4-25 ppm of colloidal nano-Ags brought about a considerable decline (P < 0.05) in NO production by macrophages. Nevertheless, there is no evidence of substantial difference at lower concentrations. This acute cytotoxic dose-dependent effect of nano-Ag particles on peritoneal macrophages which declines cell viability and NO production urges caution about the usage for sensitive surfaces. It is highly recommended to carry out the in vivo investigation for human to confirm its use.