Fig. 4
Lysosomal integrity in fibroblasts treated with polystyrene nanoparticles. a Percentage of cells with low AO fluorescence (AOlow). AO fluorescence intensity was measured by flow cytometry every 24 h for up to 72 h in fibroblasts treated with PS, PS-COOH or PS-NH2 (25 µg/mL). The results obtained from each replicate were acquired from the analysis of 10,000 cells. The percentage of cells with low AO fluorescence (AOlow) was calculated by normalizing the cell number with low AO fluorescence by the total cell number. Data are reported as mean ± SD (n = 3; p < 0.05). b Average AO fluorescence intensity measured by flow cytometry of cells treated with polystyrene nanoparticles as described in a. Data are reported as mean ± SD (n = 3; p < 0.05). c Representative histograms of cells treated with different types of polystyrene nanoparticle after 24 and 72 h. UT untreated