Chronic exposure to nanosized, anatase titanium dioxide is not cyto- or genotoxic to Chinese hamster ovary cells

Shuguang Wang, Lindsey A. Hunter, Zikri Arslan, Michael Wilkerson, Jeffrey K. Wickliffe

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Titanium dioxide nanoparticles (nano-TiO 2) are widely used in cosmetics, skin care products, paints, and water treatment processes. Disagreement remains regarding the safety of nano-TiO 2, and little epidemiological data is available to provide needed resolution. Most studies have examined effects using acute exposure experiments with relatively few studies using a chronic exposure design. We examined cyto- and genotoxicity in CHO-K1 cells following 60 days of continuous exposure to defined levels of nano-TiO 2 (0, 10, 20, or 40 μg/ml). Oxidative stress increased in a concentration-dependent manner in short- (2 days) and long-term cultures, but long-term cultures had lower levels of oxidative stress. The primary reactive oxygen species appeared to be superoxide, and ROS indicators were lowered with the addition of superoxide dismutase (SOD). No cyto- or genotoxic effects were apparent using the XTT, trypan-blue exclusion, and colony-forming assays for viability and the Comet and Hprt gene mutation assays for genotoxicity. Nano-TiO 2 increased the percentage of cells in the G2/M phase of the cell cycle, but this effect did not appear to influence cell viability or cell division. Cellular Ti content was dose-dependent, but chronically exposed cells had lower amounts than acutely exposed cells. CHO cells appear to adapt to chronic exposure to nano-TiO 2 and detoxify excess ROS possibly through upregulation of SOD in addition to reducing particle uptake.

Original languageEnglish (US)
Pages (from-to)614-622
Number of pages9
JournalEnvironmental and Molecular Mutagenesis
Volume52
Issue number8
DOIs
StatePublished - Oct 2011

Fingerprint

Cricetulus
Ovary
CHO Cells
Cell Division
Superoxide Dismutase
Oxidative Stress
Skin Care
Comet Assay
Paint
Trypan Blue
Water Purification
G2 Phase
Cosmetics
Superoxides
Nanoparticles
Reactive Oxygen Species
Cell Survival
Cell Cycle
Up-Regulation
Safety

Keywords

  • Cell cycle
  • Engineered nanomaterial
  • Mutagenicity
  • Oxidative stress
  • Superoxide

ASJC Scopus subject areas

  • Health, Toxicology and Mutagenesis
  • Epidemiology
  • Genetics(clinical)

Cite this

Chronic exposure to nanosized, anatase titanium dioxide is not cyto- or genotoxic to Chinese hamster ovary cells. / Wang, Shuguang; Hunter, Lindsey A.; Arslan, Zikri; Wilkerson, Michael; Wickliffe, Jeffrey K.

In: Environmental and Molecular Mutagenesis, Vol. 52, No. 8, 10.2011, p. 614-622.

Research output: Contribution to journalArticle

Wang, Shuguang ; Hunter, Lindsey A. ; Arslan, Zikri ; Wilkerson, Michael ; Wickliffe, Jeffrey K. / Chronic exposure to nanosized, anatase titanium dioxide is not cyto- or genotoxic to Chinese hamster ovary cells. In: Environmental and Molecular Mutagenesis. 2011 ; Vol. 52, No. 8. pp. 614-622.
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