The effect of zinc oxide and titanium dioxide nanoparticles in the Comet assay with UVA photoactivation of human sperm and lymphocytes

Abstract

The present study has examined the effects of ZnO and TiO₂ nanoparticles (40–70 nm range) in the presence and absence of UVA light in human sperm and human lymphocytes in the dark (D), after pre-irradiation with UV (PI) and simultaneous irradiation with UV (SI). For both ZnO and TiO₂ nanoparticles, the percentage reduction in head DNA was greater for PI and SI samples compared with samples treated in the dark. However with regard to photogenotoxicity, sperm exhibited no significant differences when the results for PI and SI and the dark were compared, except at the lowest concentration for SI samples in the case of ZnO and the lowest concentration for PI in the case of TiO₂. However for lymphocytes, responses were statistically significant at the highest concentration for both PI and SI samples. Thus, these studies suggest that there are photogenotoxic events in these cells in the absence of overt toxicity.

• Nanoparticles
• sperm
• lymphocytes
• Comet assay
• photo-activation
• ZnO
• TiO₂

Acknowledgements

This study was partly funded by UKIERI grant: SA07/067. We also acknowledge Dr Trish Coates for statistical advice. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.