Figure 6: Analysis of uptake mechanisms using different inhibitors. Cells were pretreated with various inhibitors, Genistein, Filipin and Chlorpromazine, for 30 min, followed by exposure to SiO2 NP in THP-1 macrophages (A and B) and A549 (C and D) cells for either 2 h (A and C) or 24 h (B and D). The uptake was quantified using flow cytometry as mean fluorescence intensities of the cells. Given are means ± SEM of 2 independent experiments, each with 3 replicas.The normalized fluorescence (% uptake) was calculated by dividing the SiO2 NP fluorescence in the presence of inhibitor by the fluorescence of controls without inhibitors.