Induction of silica nanoparticles on apoptosis of normal human peripheral blood mononuclear cells北大核心CSCD

OBJECTIVE: To elucidate the toxicological properties of silica nanoparticles (nano-SiO2) by investigating their effect on human peripheral blood mononuclear cells (PBMCs). METHODS: The particle size, morphology and dispersion of nano-SiO2 were characterized by the transmission electron microscope. Human blood samples were provided by 6 healthy volunteers, while PBMCs were isolated from the peripheral blood cells and cultured in vitro. The cells were treated with 10 nm nano-SiO2 in RPMI 1640 media at the concentration of 0 (normal control), 12.5, 25, 50, 100 and 200 mg·L-1 for 24 h. Blood routine examination was performed. The human PBMC morphology was observed under an inverted microscope, followed by detection and analysis of the microfilament using TRITC-phallodin and fluorescence microscopy, respectively. After staining with Annexin V-FITC and propidumiodide, the cell early apoptosis rate was measured by flow cytometry. Reactive oxygen species (ROS) production in the supernatant medium liquid was measured with ELISA. RESULTS: Compared with normal control group, the proportion of lymphocytes and macrophages significantly decreased when the cells were treated with nano-SiO2 100 and 200 mg · L-1. The cell morphology changed and the microfilament was disrupted. The early apoptosis rate and intracellular ROS level both significantly increased along with the nano-SiO2 exposure concentration (P<0.01). In addition, there was a significant positive correlation between ROS and apoptosis rate (R2=0.847, P<0.01). CONCLUSION: Nano-SiO2 demonstrates cytotoxicity when exposed to PBMCs. The elevated level of oxidative stress is probably a major reason for early apoptosis.