Comparison of cellular effects of titanium dioxide nanoparticles with different photocatalytic potential in human keratinocyte, HaCaT cells

Titanium dioxide (TiO2) nanoparticle is an important product for nanotechnology because of its high stability, anticorrosion, and photocatalysis. It is also used in cosmetic and skin care products, particularly in sunblocks, where it helps to protect the skin from UV light, especially in the case of nanosized particles ( <100 nm). There are extensive concerns on the potential risks of TiO2 nanoparticle to human health and environment. Some forms at least may be genotoxic, photocatalytic, and/or carcinogenic. In this study, we have characterized the physico-chemical properties of commercially available photocatalytic TiO2 nanoparticle and compared to cellular effects in HaCaT Cells with or without photoactivation. The present study has shown that TiO2 nanoparticles are cytotoxic to HaCaT cells even in the absence of photoactivation. This effect became more pronounced in the simultaneous irradiation of UVA dependent on photocatalytic potential of TiO2 nanoparticle. We also found that the cytotoxicity and oxidative stress of TiO2 nanoparticles strongly depends on physico-chemical properties including structure (anantase, rutile, or mixture) or photocatalytic potency of TiO2 nanoparticles.