Figure 2

Cell viability of A549 cells exposed to fumed silica AEROSIL® 200 NPs. After 24 h exposure to silica AEROSIL® 200 NPs, the viability of A549 cells was determined using the ATP test (black line) (Cell Titer Glo, Promega) and the XTT test (red line) (TOX2, Sigma). The results are expressed as the mean percent viable cells ± SD (n = 3) compared with unexposed cells.