Effects of the interaction of TiO2 nanoparticles with bisphenol A on their physicochemical properties and in vitro toxicity

Abstract

In this paper we evaluated the effects of the interaction of TiO(2) nanoparticles (nano-TiO(2)) with bisphenol A (BPA) on their physicochemical properties and in vitro toxicity in human embryo L-02 hepatocytes. Different concentrations of BPA (0, 0.1, 1, 10 μmol/L) and nano-TiO(2) (0, 0.1, 1, 10mg/L) were mixed to analyze the size distribution, zeta potential, adsorption capacity and uptake of nano-TiO(2), and the toxicity of nano-TiO(2) and BPA in L-02 cells. The addition of BPA to nano-TiO(2) dispersions increased the aggregation level and zeta potential of nano-TiO(2) in all media. Nano-TiO(2) had a similar adsorption capacity in different media, although a higher aggregation level was observed in cell culture medium. Nano-TiO(2), with or without BPA, could enter L-02 cells after 24h exposure. Nano-TiO(2) alone did not induce significant DNA and chromosome damage, but the mixture of nano-TiO(2) and BPA increased toxicity via increasing oxidative stress, DNA double strand breaks and micronuclei formation. The aggregated nano-TiO(2) can enrich BPA effectively. The BPA-bound nano-TiO(2) are proven to be uptaken into nuclei of exposed cells, which may increase intracellular BPA and nano-TiO(2) levels and thus lead to synergistic toxicity. However only small synergic effects were observed at the concentrations of BPA and nano-TiO(2) used in this study.