Fig. 4

Nanomaterials induce ROS/mtROS generation and mitochondrial damage. A U251 cells absorbed the nanomaterials measured by flow cytometer. B Statistics of absorption ratio characterized by SSC in U251 cells. C Nanomaterials were absorbed by U251 cells detected by TEM. Scale bar = 500 nm. D Nanomaterials induced the ROS generation detected by fluorescence microscope in U251 cells. E Quantitative analysis of ROS level in U251 cells. F Nanomaterials induced the production of mtROS detected by fluorescence microscope in U251 cells. G Quantitative analysis of mtROS level in U251 cells. H Nanomaterials impaired MMP levels measured by fluorescence microscope in U251 cells. I Quantitative analysis of MMP levels in U251 cells. Scale bar = 250 μm. *, ** and *** indicate P < 0.05, 0.01 and 0.001 compared with control group. N: Nucleus. The yellow arrow represents nanomaterials absorbed by U251 cells. Date present as mean ± SEM. n = 3