Fig. 5

Functionality, integrity and intracellular ROS levels of cells exposed at the ALI to aerosols. Mono (A549) and co-cultures (A549 + THP-1) were exposed for 3 h at the ALI to aerosols of TiO₂ (NM105, NM101, NM100) and CeO₂ (NM212) or air and kept at the ALI for 21 h in the incubator, with NMs deposited on their surface. Deposited doses were around 0.1, 1, 3 μg/cm². At 24 h, Alamar blue® and LDH assays were performed to assess functionality and integrity of the cells, respectively. A DCF assay was performed to measure intracellular ROS levels and H₂O₂ (1 mM) was used as positive control for the DCF assay (not shown on the graph). Specific air and incubator controls (cells kept in the incubator) (not shown on the graph) were used for each NM used and for each concentration tested. Data represent the mean ± SD of three independent experiments. A Kruskal-Wallis test followed by Dunn’s post-hoc test were performed to compare treated groups to control (*p < 0.05; **p < 0.01; ***p < 0.001)