In this paper we evaluated the effects of the interaction of TiO2 nanoparticles (nano-TiO2) 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 mu mol/L) and nano-TiO2 (0, 0.1, 1,10 mg/L) were mixed to analyze the size distribution, zeta potential, adsorption capacity and uptake of nano-TiO2, and the toxicity of nano-TiO2 and BPA in L-02 cells. The addition of BPA to nano-TiO2 dispersions increased the aggregation level and zeta potential of nano-TiO2 in all media. Nano-TiO2 had a similar adsorption capacity in different media, although a higher aggregation level was observed in cell culture medium. Nano-TiO2, with or without BPA, could enter L-02 cells after 24 h exposure. Nano-TiO2 alone did not induce significant DNA and chromosome damage, but the mixture of nano-TiO2 and BPA increased toxicity via increasing oxidative stress, DNA double strand breaks and micronuclei formation. The aggregated nano-TiO2 can enrich BPA effectively. The BPA-bound nano-TiO2 are proven to be uptaken into nuclei of exposed cells, which may increase intracellular BPA and nano-TiO2 levels and thus lead to synergistic toxicity. However only small synergic effects were observed at the concentrations of BPA and nano-TiO2 used in this study. (C) 2011 Elsevier B.V. All rights reserved.