中文摘要：

目的探讨具有多聚乙烯基乙二醇（PEG）作为包被材料及无PEG包被的CdSe/ZnS（内芯/外壳）量子点540的DNA损伤特性。方法分别应用细胞毒性实验（MTS）和苔盼蓝法分析经量子点540处理后人皮肤成纤维细胞的存活率和增殖情况,γH2AX焦点形成及彗星实验探讨DNA损伤情况。结果8 nmol/L和80 nmol/L有PEG包被的量子点540处理细胞后,细胞生存率及生长趋势与阴性对照相比差异无统计学意义。而无PEG包被的量子点540在同样剂量下可引起细胞生存率及生长趋势的下降。同时,无PEG包被的量子点540可使细胞核内γH2AX焦点数量以及有γH2AX焦点的细胞数量增加,有彗尾的细胞数量增加,且尾相增大。结论量子点540在PEG的包被下无明显细胞毒性。在没有PEG包被的情况下,量子点540均表现出细胞毒性以及遗传毒性作用,可导致细胞DNA的双链断裂。

英文摘要：

Objective To investigate the DNA damaging property of CdSe/ZnS（core/shell） quantum dot 540（QD540） and poly-ethylene glycol（PEG） coated QD540（P-QD540）.Methods Human skin fibroblasts（HSF） were treated with different concentrations of QD540 and P-QD540 for various times,and the cytotoxic effects were measured by MTS test and trypan blue exclusion.DNA double strand breaks（DSBs） were detected by the neutral comet assay and γH2AX foci formation.Results It was found that P-QD540 did not have significant cytotoxic effects,while QD540 showed cytotoxic effects at either 8 nmol/L or 80 nmol/L in a time-dependent manner.In addition,γH2AX foci were induced by 8 nM or 80 nM QD540 in HSF cells in a time-dependent manner.Neutral comet assay also revealed induction of DSBs.Conclusion P-QD540 does not have significant cytotoxic effects.On the other hand,QD540 shows cytotoxic and genotoxic effects on HSF cells,which can induce DNA DSBs.