Fig. 1

Polystyrene nanoparticles promote TFEB activation in HeLa/TFEB cells. a Average fraction of TFEB that localizes in the nucleus of HeLa/TFEB cells untreated and treated with PS (50 and 100 µg/mL), PS-COOH (50 and 100 µg/mL), and PS-NH₂ (10 and 25 µg/mL) for 24 h. Representative fields (~30) each containing approximately 50 cells were analyzed and data reported as mean ± SD (n = 3; p < 0.01). b Representative confocal microscopy images of TFEB subcellular localization in HeLa/TFEB cells treated with nanoparticles as described in a. UT, untreated. The scale bar is 10 μm. c Cellular uptake of polystyrene nanoparticles in HeLa/TFEB cells treated with nanoparticles as described in a. Data are reported as mean ± SD (n = 3; p < 0.05). d Confocal microscopy analyses of calcein (green) and EthD-1 binding (red) in HeLa/TFEB cells treated with PS (50 µg/mL), PS-COOH (50 µg/mL), and PS-NH₂ (10 µg/mL) for 24 h. UT untreated. The scale bar is 40 μm