Cytotoxicity and DNA damage evaluation of TiO2 and ZnO nanoparticles. Uptake in lung cells in culture

The cytotoxicity and DNA damage of titanium dioxide and zinc oxide nanoparticles (TiO2 and ZnO NPs) have been studied in a human lung carcinoma cell line (A549) after 24 h exposure. TiO2 and ZnO NPs had mean diameters of 12.9 +/- 2.8 and 24.1 +/- 8.0 nm, respectively. ZnO NPs reduced cell viability from 250 mu g/mL, increasing reactive oxygen species (ROS) and decreased GSH/GSSG ratio. The comet assay detected DNA damage from 50 mu g/mL. TiO2 NPs induced cytotoxicity and DNA damage from 50 to 100 mu g/mL, respectively, along with a decrease of the GSH/GSSG ratio. Both particles were found inside the cells, within membrane-bound vesicles. The internalization mechanism is promoted partially by caveolae-mediated endocytosis and, in the case of TiO2 NPs, also by macropinocytosis.

Automated summary

The cytotoxicity and DNA damage of titanium dioxide and zinc oxide nanoparticles were studied in a human lung carcinoma cell line after 24 hours exposure. Both particles induced effects on cell viability and DNA damage at different concentrations, entering the cells and increasing reactive oxygen species internally.