中文摘要：

目的探讨Fe2O3纳米粒子对小鼠腹腔巨噬细胞（RAW264．7）的活力与凋亡的影响。方法Fe2O3纳米粒子对RAW264．7细胞染毒，用四甲基偶氮噻唑蓝（MTT）比色法确定受试物的染毒剂量。用0．24，0．48，0．96mg／ml Fe2O3纳米粒子染毒，并设阴性对照组。分别对各个组行乳酸脱氢酶（LDH）活力测定、流式细胞术检测细胞线粒体膜电位（MMP）变化及凋亡。结果MTT试验结果表明，Fe2O3纳米粒子在0．816～3．523mg／ml范围内均可抑制RAW264．7细胞增值，半数抑制浓度（IC50）为1．76mg／ml。Fe2O3纳米粒子在0，0．24，0．48，0．96mg／ml剂量组的细胞外液中LDH活力高于对照组（P〈0．05）；流式细胞仪检测结果表明，剂量组细胞线粒体膜电位均较对照组有所下降，且细胞凋亡率显著增高。结论Fe2O3纳米粒子可以抑制RAW264．7的增殖并导致细胞膜通透性的增加，在一定剂量范围内引起线粒体膜电位的降低最终导致细胞凋亡。

英文摘要：

Objective To study the effect of Fe2O3 nanoparticles on proliferation and apoptosis and the oxidative damage of RAW 264.7 cells. Methods The cytotoxicity and intervening concentration of nanoparticles were detected by MTT assays. 0.24, 0.48 and 0.96 mg/ml Fe2O3 nanoparticles suspension- intervened macrophages were set as Fe2O3 nanoparticle groups, and normal saline group was set as control group. The levels of LDH activity in medium were analyzed using the reagent kits. The mitochondrial membrane potent （MMP） and cell apoptosis rate were analyzed by flow cytometry. Results The proliferations of RAW 264.7 cells were suppressed when exposed to Fe2O3 nanoparticles of 0. 816-3. 523 mg/ml. The IC50 of Fe2O3 nanoparticles on RAW 264.7 cells was 1.76 mg/ml. The levels of LDH activity in Fe2O3 nanoparticle groups were higher than that of control group （P 〈 0.05）. Flow cytometry assay showed that the MMP decreased in different exposure groups and cell apoptosis rate of exposure groups were higher than that of the control （ P 〈 0.05）. Conclusion Fe2O3 nanoparticles could cause cytotoxicity, increase cell membrane permeability and depress the activities of LDH. Fe2O3 nanopartitles could also reduce the MMP and lead to apoptosis in RAW 264.7 cells.