Comparative Cytotoxicity induced by Zinc Oxide Nanoparticles in Human Prostate Cells.

Despite increasing biomedical applications of zinc oxide nanoparticles (ZnO NPs), there is a lack of information concerning the biological effects of ZnO NPs on human cells. The purpose of this study was to assess the comparative cytotoxicity in human prostate cells (PC-3 and RWPE-1) exposure to 20-nm ZnO NPs. Exposure to concentrations from 0 to 50 µg/mL of ZnO NPs reduced cell viability of PC-3 cells in a dose- and time-dependent manner; whereas it did not affect RWPE-1 cells. A dose-dependent increase in LDH leakage and intracellular reactive oxygen species was observed in PC-3 cells but not in RWPE-1 cells exposure to ZnO NPs at concentrations of 8 ˜ 50 µg/mL for 24 h (P < 0.05). That the percentage of apoptotic cells increased significantly was observed in PC-3 cells induced by ZnO NPs at 10 µg/mL exposure for 8 h. Our results showed that ZnO NPs induced in vitro preferential cytotoxicity in the human prostate cancer cells. We indicated that the different cytotoxicity of ZnO NPs is likely due to the different cell-nanoparticle interaction and response behavior rather than to hydrodynamic sizes of particles. It is suggested that ZnO NPs are expected to find a very promising targeting therapeutic application for human prostate cancer.