Antibacterial applications of silver nanoparticles: Benefits and human health risks

The minimum inhibitory concentrations (MICs) assays conducted for E. coli, S. aureus, B. subtilis and P. phoeniceum have shown that the antimicrobial activity of silver ions was superior to that of silver nanoparticles. As silver nanoparticles can be more suitable in some bactericidal applications than silver ions, the efficacy of nanosilver as an antimicrobial agent against a range of microbes on the surface of water paints and cotton fabrics has been studied. The cytotoxicity of silver nanoparticles has been studied using NIH-3T3, HEP-G2, A-549, PC-12, and Colo-320 cells via the MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium-bromid) test. The MTT test results obtained have shown that silver nanoparticles in concentrations of ~1-10 ppm entering the body from air or liquid suspensions can present a potential risk to human health. However, silver nanoparticles as a commercially viable addition to be used in paint and textile industry are unlikely to present a direct health risk.