Toxicogenomic effects of nano- and bulk-TiO₂ particles in the soil nematode Caenorhabditis elegans

Abstract

The toxicity and toxicogenomics of selected anatase and rutile nanoparticles (NP) and bulk titanium dioxide (TiO₂) particles were evaluated in the soil nematode Caenorhabditis elegans. Results indicated that bulk or nano-TiO₂ particles were slightly toxic to soil nematode C. elegans, as measured by reproduction EC₅₀ values ranging from 4 to 32 mg/L. Whole-genome microarray results indicated that the regulation of glutathione-S-transferase gst-3, cytochrome P450 cypp33-c11, stress resistance regulator scl-1, oxidoreductase wah-1 and embryonic development pod-2 genes were significantly affected by nano-sized and bulk-TiO₂ particles. More specifically, it was determined that anatase particles exerted a greater effect on metabolic pathways, whereas rutile particles had a greater effect on developmental processes. The up-regulation of the pod-2 gene corroborated the phenotypic effect observed in the reproduction test. Our results demonstrated that C. elegans is a good genomic model for nano-TiO₂ toxicity assessment.

• Gene expression
• juglone
• nanoparticles
• oxidative stress
• titanium dioxide

Acknowledgements

The authors thank Chun Wai Yip, Isabelle Beaulieu, Myrianne Joly, Pierre-Michel Bergeron, Catherine Dimacacos, Manon Sarrazin, and Sabine Dodard for their much appreciated technical support throughout the project. This publication was assigned NRC # 55498.

Declaration of interest

This research was funded by the National Research Council of Canada (NRC) – Natural Sciences Engineering Research Council (NSERC) – Business Development Bank of Canada (BDC) Nanotechnology Initiative (NNBNI) grant.

Supplementary material available online.

Supplemental Figures S1 and S2.