Abstract:  

 This experiment was to explore the effects of concentration and size of ZnO Nanoparticles (ZnO NPs) on HEK293 cells and research its mechanism of toxicity. In this experiment, we used three different sizes ZnO NPs which include 15nm-sized ZnO NPs, 30 nm-sized ZnO NPs, 90nm-sized ZnO NPs and normal ZnO to treat HEK293 cells. After 48 hours, we detected the cell proliferation by MTT test, then we made a cell cytometry to investigate the rate of apoptosis. Last, we analyzed the change of ROS level by kit. There was no noticeable changes on HEK293 cells treated with 15nm-sized ZnO NPs below 2.0μg/mL concentration. While above 4.0μg/mL, the proliferation of HEK293 cells was reduced significantly. However therate of apoptosis and the level of ROS increased obviously. With the decrease of the size of ZnO NPs, the rate of apoptosis and the level of ROS increased, but the proliferation of cell gradually reduced in HEK293 cells. In this experiment, the result suggest that cytotoxicity of ZnO NPs on HEK293 cells be related to its concentration and size. Increasing of ROS induced by ZnO NPs may be one important element of cytotoxicity.