Comparative toxic effect of bulk zinc oxide (ZnO) and ZnO nanoparticles on human red blood cells

Abstract Metal oxide nanoparticles (NPs) are a member of nanomaterials family that have been produced on a large scale and their toxicity affected by their high surface-to-volume ratio. The hemolytic toxic effects of metal oxide NPs may be completely different from those observed in their bulk counterparts. So, the main purpose of this research was to measure the difference between the hemolytic effects of ZnO (NPs and bulk) on isolated human red blood cells (RBCs). Hemolysis was measured after incubation of human RBCs with 0.01–1 mM of ZnO (bulk and NPs) for 6 h. For measurement of other variables, human RBCs were treated with 0.1 mM of ZnO (NPs and bulk) for 1, 2, and 3 h. Our results demonstrate that bulk ZnO did not show any toxic effects in the concentrations tested, while ZnO NPs caused toxic hemolytic effects through formation of ROS, lipid peroxidation, and glutathione depletion.