| Abstract [eng] |
Polystyrene nanoparticles (PS-NPs) are one of the most represented NPs in the environment. In vivo and in vitro studies have suggested that PS-NPs may penetrate organisms through several routes i.e. skin, respiratory and digestive tracts. One of the main concerns of PS-NPs exposure is their genotoxic potential. In this study, we investigated the cytotoxicity and genotoxicity of 70 nm size PS nanoparticles in the human hepatoma cell line HepG2 in vitro. First of all, the PS nanoparticles uptake by HepG2 cells and their ability to generate reactive oxygen species was evaluated. AlamarBlue and trypan blue exclusion assays were performed to assess cell viability. To evaluate primary DNA damage induced by PS nanoparticles, the alkaline comet assay was employed, while oxidative DNA damage was assessed using enzyme-modified (Fpg and EndoIII) comet assay. The AlamarBlue test did not show a decrease in relative fluorescence intensity signal of more than 20 %. Meanwhile, the trypan blue assay indicated that after 24 hours of incubation with various concentrations of PS nanoparticles, the viability of HepG2 cells decreased significantly at concentrations of 10, 60, 80, and 100 µg/ml. However, none of the tested concentrations were considered cytotoxic. The alkaline and enzyme-modified comet assays revealed that all concentrations of PS-NPs tested (5100 µg/ml) were significantly associated with increased primary and oxidative DNA damage in HepG2 cells, where the highest proportion of damage was attributed to oxidized purines. |
