Effects of Silicon Dioxide Nanoparticles on Apoptosis of HaCaT Cells

[Objective] To investigate the effects of silicon dioxide nanoparticles(nano-SiO2) of different particle size(15,30,100 nm) and standard SiO2 particles(micro-SiO2) on proliferation and apoptosis of HaCaT cells.[Method] HaCaT cells were treated by 15,30,100 nm nano-SiO2(2.5,5,10 μg/ml) particles and micro-SiO2(10 μg/ml) particles for 24 h,at the same time,the solvent control was set.The level of ROS and the effect of cell growth inhibition were assayed by 2′,7′-dichlorfluorescein-diacetate(DCFH-DA) and cell counting kit(CCK-8) Kit respectively.Apoptosis were assayed by Annexinⅴ-PI double staining and Hoechst 33342 staining method.[Method] HaCaT cells were treated by 15,30,100 nm nano-SiO2(2.5,5,10 μg/ml) particles and micro-SiO2(10 μg/ml) particles for 24 h,at the same time,the solvent control was set.The level of ROS and the effect of cell growth inhibition were assayed by 2′,7′-dichlorfluorescein-diacetate(DCFH-DA) and cell counting kit(CCK-8) Kit respectively.Apoptosis were assayed by Annexinⅴ-PI double staining and Hoechest 33342 staining method.[Result] As observed in the CCK-8 kit,exposure to nano-SiO2 nanoparticles for 24 h,the IC50 was 19.4 ± 1.3,27.7 ± 1.5 and 35.9±1.6 μg/ml for 15,30 and 100 nm SiO2 nanoparticles,respectively.Exposure to SiO2 nanoparticles results in a concentration-and size-dependent cytotoxicity and increase in intracellular ROS level and apoptosis rate were also observed in SiO2 nanoparticle-exposed HaCaT cells.Cytotoxicity and apoptosis in cultural HaCaT cells that is closely correlated to increased oxidative stress,the correlation coefficient was-0.952 and 0.898 respectively.[Conclusion] nano-SiO2 may affect proliferation and apoptotic rates of HaCaT cells via stimulating the production of ROS in cells.