Cytotoxicity and genotoxicity of silver nanoparticles in Chinese Hamster ovary cell line (CHO-K1) cells

Biomedical and pharmaceutical products comprising silver nanoparticles are attracting interest due to their potent antibacterial activities. For their safe use it has become imperative to test their cyto-genotoxic potential. In the present study the cytotoxicity and genotoxicity of three different sizes of AgNPs ranging from 15 to 22 nm and at concentrations 0.005–500 μg/ml were studied in Chinese Hamster ovary cell line (CHO-K1) cells. Cytoxicity was assessed by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and for genotoxicity comet, and micronucleus assays were utilized. AgNPs were able to internalize CHO-K1 cells and cause cytotoxicity at concentrations 0.005–500 μg/ml. AgNP‐induced cyto-genotoxicity in CHO-K1 cells could be attributed to its smaller primary size. AgNP-C of size ~ 15 nm was the most potent among the three AgNPs. The genotoxic response was biphasic that increased at lower concentrations (0.005–0.025 μg/ml) and decreased at higher concentrations (0.05–0.1 μg/ml) after 24 h of exposure. Such potential in vitro genotoxic effect of AgNPs remains to be further confirmed in animal cells in vivo.