Cytotoxicity and genotoxicity of silver nanoparticles of different sizes in CHO-K1 and CHO-XRS5 cell lines.

Nanoparticles (NPs) have been used in a range of products due to their unique properties. Nevertheless, these NPs can cause adverse biological effects and because of that, there is a great concern about the health and environmental risks related to their use. Recently, silver nanoparticles (Ag NPs) have been used in a variety of cytotoxicity and genotoxicity studies, but there are still controversies regarding the association between the size and the toxicity of these particles. Therefore, in this study, we aimed to evaluate the cytotoxicity and genotoxicity of Ag NPs (10 and 100 nm) in two different cell lines, CHO-K1 and CHO-XRS5, by performing cell viability assay (XTT), clonogenic assay, micronucleus test, comet assay, as well as by investigating the cell cycle kinetics using the flow cytometry. Cell cultures were exposed to different concentrations of AgNPs (0.025-5.0 μg/ml) for 24 h. Our results indicated that cytotoxicity and genotoxicity induced by the 100 nm-Ag NPs were greater than those induced by the 10 nm-Ag NPs for both cell lines, which suggests that the exposure to greater size particles (100 nm) can cause more adverse biological effects than the exposure to the smaller ones (10 nm).