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

FREIRE, K; ORDÓÑEZ RAMOS, F; SORIA, D B; PABÓN GELVES, E; DI VIRGILIO, A L

Toxicology Research

Oxford University Press

Año: 2021 vol. 10 p. 192 - 202

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 μg/mL, increasing reactive oxygen species (ROS) and decreased GSH/GSSG ratio. The comet assay detected DNA damage from 50 μg/mL. TiO2 NPs induced cytotoxicity and DNA damage from 50 to 100 μg/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