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目的探讨不同粒径、不同浓度的纳米二氧化硅(nm-SiO2)染毒人永生化表皮(HaCaT)细胞内活性氧簇(reactive oxygen species,ROS)水平以及超氧化物歧化酶(superoxide dismutase,SOD)和过氧化氢酶(catalase,CAT)活力的变化。方法将对数生长期HaCaT细胞置于含终浓度分别为0(对照)、2.5、5、10、20、40、60μg/ml的15、30、100 nm三种粒径纳米二氧化硅溶液的MEM基础培养基中培养24 h后,测定细胞增殖情况,并计算半数抑制浓度(IC50)。将对数生长期HaCaT细胞置于含终浓度分别为0(对照)、5、10、15μg/ml的15、30、100 nm三种粒径纳米二氧化硅溶液的MEM基础培养基中培养24 h。分别检测细胞内ROS的水平和SOD、CAT的活力。结果细胞存活率随着纳米二氧化硅粒径的增大而上升,随着染毒浓度的升高而下降。粒径为15、30、100 nm的纳米二氧化硅染毒HaCaT细胞的IC50分别为(19.43±1.30),(27.67±1.44),(35.91±1.59)μg/ml。与对照组相比,各粒径、各浓度纳米二氧化硅染毒HaCaT细胞内ROS水平均升高,差异有统计学意义(P<0.05);HaCaT细胞内ROS水平随着纳米二氧化硅粒径的增大而下降,随着染毒浓度的升高而上升。随着浓度的升高,粒径为15 nm的纳米二氧化硅染毒HaCaT细胞内SOD水平呈升高趋势,粒径为30 nm的纳米二氧化硅染毒HaCaT细胞内SOD水平呈先升高后下降的趋势,粒径为100 nm的纳米二氧化硅染毒HaCaT细胞内SOD水平呈波动趋势。与对照组相比,各粒径、各浓度纳米二氧化硅染毒HaCaT细胞内CAT活力均升高,差异有统计学意义(P<0.05);且随着浓度的升高,各粒径二氧化硅染毒HaCaT细胞内CAT活力均呈先上升后下降的趋势。结论不同粒径的纳米二氧化硅均具有明显的细胞毒性;在一定剂量范围内,不同粒径纳米二氧化硅染毒可以诱导细胞内ROS水平均明显增加,并明显改变相关抗氧化酶SOD和CAT的酶活力水平。
Objective To investigate the levels of reactive oxygen species (ROS) and superoxide dismutase (SOD) in human immortalized epidermis (HaCaT) cells exposed to different particle sizes and different concentrations of nano- SOD and catalase (CAT) activity changes. Methods HaCaT cells in logarithmic growth phase were cultured in the presence of 15, 30, 100 nm three-size nano-silica solutions at final concentrations of 0 (control), 2.5, 5, 10, 20, 40 and 60 μg / After cultured for 24 h in MEM basal medium, the cell proliferation was measured and the half inhibitory concentration (IC50) was calculated. The logarithmic growth phase HaCaT cells were cultured in MEM basal medium containing 15, 100, and 100 nm final concentrations of 0, 5, 10 and 15 μg / ml of three particle size nanosilica solutions respectively h The level of intracellular ROS and the activity of SOD and CAT were detected respectively. Results The cell viability increased with the particle size of nano-silica and decreased with the increase of the concentration of nano-silica. The IC50 of HaCaT cells exposed to nano-silica with diameters of 15, 30 and 100 nm were (19.43 ± 1.30), (27.67 ± 1.44) and (35.91 ± 1.59) μg / ml, respectively. Compared with the control group, the ROS levels of HaCaT cells with various particle sizes and concentrations of nano-silica increased, with significant difference (P <0.05). The level of ROS in HaCaT cells increased with the increase of nano-silica particles Diameter increased and decreased, with the concentration increased. With the increase of concentration, the SOD level in HaCaT cells exposed to nano-silica with a particle size of 15 nm tended to increase. The SOD level in HaCaT cells with nano-silica particles with a diameter of 30 nm first increased After descending, the SOD level in HaCaT cells exposed to nanosilica with particle size of 100 nm fluctuated. Compared with the control group, CAT activity in HaCaT cells treated with nano-silica and various particle sizes increased with a significant difference (P <0.05). With the increase of concentration, The activity of CAT in HaCaT cells exposed to silicon dioxide increased first and then decreased. CONCLUSION: Nanosilica with different particle size has obvious cytotoxicity. Within a certain dose range, the nano-silica with different particle size can induce the intracellular ROS levels to increase significantly, and significantly change the relative antioxidant enzymes SOD and CAT activity levels.