Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, SI-1000 Ljubljana, Slovenia.
J Hazard Mater. 2011 Nov 30;196:145-52. doi: 10.1016/j.jhazmat.2011.09.004. Epub 2011 Sep 8.
Titanium dioxide (TiO(2)) is active in the UV region of the light spectra and is used as a photocatalyst in numerous applications. Photo-activated anatase TiO(2) particles promote increased production of free radicals. This is a desirable property, although the potential toxicity of such photo-activated TiO(2) particles on exposure of humans and the environment remains unknown. Therefore, we studied whether pre-irradiation of TiO(2) particles with UV influences their cytotoxic and genotoxic potential. The TiO(2) particles, as TiO(2)-A (<25 nm) and TiO(2)-B (>100 nm), were UV pre-irradiated (24h) and tested for cytotoxic and genotoxic activities in human hepatoma HepG2 cells. Non-irradiated TiO(2)-A/B at 1.0-250 μg/ml did not reduce viability of HepG2 cells, nor induce significant increases in DNA strand breaks; only TiO(2)-A induced significant increases in oxidative DNA damage. After UV pre-irradiation, both TiO(2)-A and TiO(2)-B reduced cell viability and induced significant increases in DNA strand breaks and oxidative DNA damage. This is the first study that shows that UV pre-irradiation of anatase TiO(2) particles results in increased cytotoxic and genotoxic potential. This warrants further studies as it has important implications for environmental and human health risk assessment and preventive actions to limit human exposure.
二氧化钛（TiO2）在光光谱的紫外区域活跃，并且在许多应用中用作光催化剂。光激活锐钛矿 TiO2 颗粒促进自由基的产生增加。虽然人类和环境暴露于这种光激活 TiO2 颗粒的潜在毒性仍然未知，但这种特性是理想的。因此，我们研究了 TiO2 颗粒在紫外光照射下预先照射是否会影响其细胞毒性和遗传毒性。TiO2 颗粒（TiO2-A（<25nm）和 TiO2-B（>100nm））用 UV 预先照射（24 小时），并在人肝癌 HepG2 细胞中测试其细胞毒性和遗传毒性活性。未辐照的 TiO2-A/B 在 1.0-250μg/ml 时不会降低 HepG2 细胞的活力，也不会引起 DNA 链断裂的显著增加；只有 TiO2-A 引起了显著的氧化 DNA 损伤增加。经 UV 预先照射后，TiO2-A 和 TiO2-B 均降低了细胞活力，并引起 DNA 链断裂和氧化 DNA 损伤的显著增加。这是第一项表明锐钛矿 TiO2 颗粒的 UV 预先照射会导致细胞毒性和遗传毒性增加的研究。这需要进一步研究，因为它对环境和人类健康风险评估以及限制人类暴露的预防措施具有重要意义。
