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The Genotoxicity of Titanium Dioxide and Cerium Dioxide Nanoparticles in Human Respiratory Epithelial Cells
Citation:
Prasad, R. Y., A. H. TENNANT, A. D. KLIGERMAN, C. F. BLACKMAN, AND D. M. DEMARINI. The Genotoxicity of Titanium Dioxide and Cerium Dioxide Nanoparticles in Human Respiratory Epithelial Cells. Presented at Environmental Mutagen Society 41st Annual meeting, Ft. Worth, TX, October 23 - 27, 2010.
Impact/Purpose:
This poster presents results from a series of studies on the genotoxicity of titanium dioxide and cerium dioxide nanoparticles in mammalian cells.
Description:
Due to the exponential growth of the nanomaterial industry, risk assessment of human exposure to nanomaterials in consumer products is of paramount importance. The genotoxicity of nanomaterials is an important aspect of hazard identification and regulatory guidance. However, this literature does not always characterize adequately the particles and frequently has conflicting genotoxicity results. We investigated the genotoxicity of two titanium dioxide (Degussa P25 Ti02, 27.5 nm, anatase/rutile mixture and Alfa Aesar Ti02, 32 nm, anatase) and one cerium dioxide (NanoAmor Ce02, 15-30 nm) nanomaterials on human tracheal epithelial cells (BEAS-2B) at concentrations of 10-150 ug/ml. We prepared nanomaterials 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 ofthe surfactant DSPC (DM), to determine whether the degree of agglomeration impacts genotoxicity. Sizing ofthe nanomaterials was determined using dynamic-light scattering. The size of nanomaterials in DM was significantly smaller than in KGM at all concentrations. Cytotoxicity was assessed by trypan blue dye exclusion and confirmed using Live/Dead'" staining. Degussa P25 Ti02at 150 ug/ml was significantly cytotoxic. 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 Ti02 nanomaterials but not for Ce02 nanomaterials. None of the nanomaterials induced micronuclei in KGM. We are currently investigating the genotoxic effects of these nanomaterials in DM. [Abstract does not necessarily reflect the policies of the U.S. EPA.]