title: Titanium Dioxide Nanoparticles are not Cytotoxic or Clastogenic in Human Skin Cells.
abstract: The application of nanoparticle technology is rapidly expanding. The reduced dimensionality of nanoparticles can give rise to changes in chemical and physical properties, often resulting in altered toxicity. People are exposed dermally to titanium dioxide (TiO2) nanoparticles in industrial and residential settings. The general public is increasingly exposed to these nanoparticles as their use in cosmetics, sunscreens and lotions expands. The toxicity of TiO2nanoparticles towards human skin cells is unclear and understudied. We used a human skin fibroblast cell line to investigate the cytotoxicity and clastogenicity of TiO2nanoparticles after 24 h exposure. In a clonogenic survival assay, treatments of 10, 50 and 100 μg/cm2induced 97.8, 88.8 and 84.7% relative survival, respectively. Clastogenicity was assessed using a chromosomal aberration assay in order to determine whether TiO2nanoparticles induced serious forms of DNA damage such as chromatid breaks, isochromatid lesions or chromatid exchanges. Treatments of 0, 10, 50 and 100 μg/cm2induced 3.3, 3.0, 3.0 and 2.7% metaphases with damage, respectively. No isochromatid lesions or chromatid exchanges were detected. These data show that TiO2nanoparticles are not cytotoxic or clastogenic to human skin cells.
authors.affiliation: Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, Portland ME 04103, USA ; Maine Center for Toxicology and Environmental Health, University of Southern Maine, Portland ME 04103, USA ; Graduate School of Biomedical Science and Engineering, University of Maine, Orono ME 04469, USA.
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Browning
authors.affiliation: Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, Portland ME 04103, USA ; Maine Center for Toxicology and Environmental Health, University of Southern Maine, Portland ME 04103, USA.
authors.forename: Therry
authors.initials: T
authors.lastname: The
authors.affiliation: Graduate School of Biomedical Science and Engineering, University of Maine, Orono ME 04469, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Mason
authors.affiliation: Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, Portland ME 04103, USA ; Maine Center for Toxicology and Environmental Health, University of Southern Maine, Portland ME 04103, USA ; Graduate School of Biomedical Science and Engineering, University of Maine, Orono ME 04469, USA.
authors.forename: John Pierce
authors.initials: JP
authors.lastname: Wise
keywords: Chromosome aberration; Clastogenicity; Nanotoxicology; Skin fibroblasts; Titanium dioxide