Objective To study the toxic effects of SiO2 nanoparticles (nano-SiO2) on human pulmonary adenocarcinoma A549 cells.
Methods Different concentrations of nano-SiO2 (10-20 nm) (5, 10, 25, 50, and 100 mg/L) were evaluated for their potential toxicity in A549 cells. Cell viability was determined by MTT assay, lactate dehydrogenase (LDH) activity by colorimetric analysis method, microstructure of organelle by transmission electron microscope, and apoptosis and cell cycle by flow cytometry.
Results Compared with the control group, exposure to increasing concentrations of nano-SiO2 resulted in a diminishing viability of A549 cells. The activity of LDH increased in a dose-dependent manner with nano-SiO2 from 0 to 25 mg/L (P < 0.01 or P < 0.05), decreased at 50 mg/L nano-SiO2, and then increased at 100 mg/L nano-SiO2. With the increase of nano-SiO2 concentrations, cell membrane villi decreased; organell cavity changes increased; secondary lysosomes increased; more cell apoptosis or necrosis appeared; A549 cells were arrested at G0/G1 phase and proliferation was inhibited.
Conclusion Nano-SiO2 can be uptaken by A549 cells, resulting in impaired organelle structure and function, thus inhibiting cell proliferation, inducing cell apoptosis, and causing cell cyclical disorders.
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