Fig. 1

Lysosome dysfunction upon incubation with nanoparticles. (A) A549 cells were incubated with PBS, iron oxide, silica, or alumina for 48 h, and then their viability was examined by an MTS assay. (B) Immunoblot analysis of LAMP1 in A549 cells treated with nanoparticles at the indicated concentrations; β-actin was used as the control. (C) Twenty-four hours post incubation with 30 μg/mL nanoparticles, cells were stained with LysoTracker. Images were acquired using confocal microscopy, and the fluorescence signal intensity of each cell, as shown on the right, was estimated by examining more than 100 cells. The data are presented as the mean ± S.E.M. of three independent experiments. *P < 0.05, **P < 0.01