Fig. 4

Levels of pro-inflammatory mediators IL-1β, IL-6, IL-8 and TNF-α in culture medium 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 in the incubator at the ALI for 21 h, with NMs deposited on their surface. Deposited doses were around 0.1, 1, 3 μg/cm². At 24 h, IL-1β, IL-6, IL-8 and TNF-α levels in the culture medium were measured by ELISA multiplex at the basal side. For exposures at the ALI, specific air and positive controls (LPS 20 μg/mL) (not shown on the graph) were used for each NM used and for each concentration tested. Data represent the mean ± Standard Deviation (SD) of three independent experiments. A Kruskal-Wallis test followed by Dunn’s post-hoc test were performed to compare treated groups to controls (*p < 0.05; **p < 0.01; ***p < 0.001)