Titanium Dioxide Induces Apoptosis under UVA Irradiation via the Generation of Lysosomal Membrane Permeabilization-Dependent Reactive Oxygen Species in HaCat Cells

Titanium dioxide nanoparticles (TiO2 NPs) have wide commercial applications, owing to their small size; however, the biosafety of TiO2 NPs should be evaluated further. In this study, we aimed investigate cytotoxicity in presence and absence ultraviolet A (UVA) irradiation human keratinocyte HaCaT cells. did not significantly affect cell viability UVA irradiation. Nonetheless, UVA-irradiated induced caspase-dependent apoptosis Exposure cells resulted reactive oxygen species (ROS) generation lysosomal membrane permeabilization (LMP); both effects were observed An analysis relationship between LMP ROS, using CA-074 as a cathepsin inhibitor or NAC an antioxidant, showed that stimulates ROS under these conditions. These results imply LMP-dependent oxidative stress plays critical role phototoxicity