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Genotoxic Effects of Titanium Dioxide and Cerium Dioxide Nanoparticles in Human Respiratory Epithelial Cells
Citation:
Wallace, K., A. H. Tennant, A. D. Kligerman, C. F. BLACKMAN, AND D. M. DEMARINI. Genotoxic Effects of Titanium Dioxide and Cerium Dioxide Nanoparticles in Human Respiratory Epithelial Cells. Presented at Genetics and Environmental Mutagenesis Society (GEMS) meeting, RTP, NC, October 15, 2010.
Impact/Purpose:
The genotoxicity of nanomaterials is a fundatmental aspect of hazard identificaiton and regulatory guidance.
Description:
The nanomaterial industry has recently seen rapid growth, therefore, the risk assessment of human exposure to nanomaterials in consumer products is of paramount importance. The genotoxicity of nanomaterials is a fundamental aspect of hazard identification and regulatory guidance. However, reports do not always characterize adequately the particles and frequently have conflicting genotoxicity results. We investigated the genotoxicity of two titanium dioxide (Degussa P25 TiO2, 27.5 nm, anatase/rutile mixture and Alfa Aesar TiO2, 32 nm, anatase) and one cerium dioxide (NanoAmor CeOz, 15-30 nm) nanomaterials on human tracheal epithelial cells (BEAS-2B) at concentrations of 10-150 ug/ml in KGM and 10-100 ug/ml in DM. Nanomaterials were prepared in two different treatment media: keratinocyte growth media (KGM) with 0.1% BSA, or with PBS with 0.6 mg/ml BSA plus 0.01 mg/ml of the surfactant DSPC (DM), to determine whether the degree of agglomeration impacts genotoxicity. Dynamic light scattering was used to determine the size of nanomaterials: in DM, size was significantly smaller than in KGM at all concentrations. Cytotoxicity was assessed in KGM by trypan blue dye exclusion and confirmed using Live/Dead@ staining, and only Degussa P25 TiO2 was cytotoxic at 150 ug/ml. To investigate genotoxicity, the comet assay and micronucleus test with kinetochore staining were performed. In KGM, the % tail DNA was increased significantly at all concentrations for both TiO2 nanomaterials but not for CeO2 nanomaterials. None of the nanomaterials induced micronuclei in KGM. We are currently investigating the cytotoxic and genotoxic effects of these nanomaterials in DM. [Abstract does not necessarily reflect the policies of the U.S. EPA.