Abstract
Titanium dioxide nanoparticles (TiO2-NPs) induced cytotoxicity and DNA damage have been investigated using human amnion epithelial (WISH) cells, as an in vitro model for nanotoxicity assessment. Crystalline, polyhedral rutile TiO2-NPs were synthesized and characterized using X-ray diffraction (XRD), UV-Visible spectroscopy, Fourier transform infra red (FTIR) spectroscopy, and transmission electron microscopic (TEM) analyses. The neutral red uptake (NRU) and [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assays revealed the concentration dependent cytotoxic effects of TiO2-NPs (30.6 nm) in concentration range of 0.625-10 mu g/ml. Cells exposed to TiO2-NPs (10 mu g/ml) exhibited significant reduction (46.3% and 34.6%; p < 0.05) in catalase activity and glutathione (GSH) level, respectively. Treated cells showed 1.87-fold increase in intracellular reactive oxygen species (ROS) generation and 7.3% (p < 0.01) increase in G(2)/M cell cycle arrest, as compared to the untreated control. TiO2-NPs treated cells also demonstrated the formation of DNA double strand breaks with 14.6-fold (p < 0.05) increase in Olive tail moment (OTM) value at 20 mu g/ml concentration, vis-A-vis untreated control, under neutral comet assay conditions. Thus, the reduction in cell viability, morphological alterations, compromised antioxidant system, intracellular ROS production, and significant DNA damage in TiO2-NPs exposed cells signify the potential of these NPs to induce cyto- and genotoxicity in cultured WISH cells. (C) 2011 Elsevier Ltd. All rights reserved.