巯基乙酸-碲化镉量子点对人肝细胞毒性和DNA损伤的诱导作用

目的：研究巯基乙酸（TGA）包覆的碲化镉(CdTe)量子点（QDs）对人正常肝HL-7702细胞的毒性和DNA损伤的作用，为QDs毒理学研究和安全性评价提供实验依据。方法：实验设立对照组和不同浓度CdTe QDs作用组（浓度分别为6.25、12.50、25.00和50.00 mg/L）。CdTe QDs作用于HL-7702细胞后，分别采用MTT法检测细胞增殖变化，单细胞凝胶电泳法（SCGE）检测细胞DNA损伤情况，PI单染流式细胞术（FCM）检测细胞周期变化，AO/EB双荧光染色法和Annexin Ⅴ- FITC/PI双染FCM检测细胞凋亡情况。结果：MTT法，CdTe QDs可抑制HL-7702细胞增殖，并存在剂量-效应和时间-效应关系；SCGE和PI单染FCM法，CdTe QDs作用于HL-7702细胞24 h后，随着剂量的增加，DNA损伤率逐渐增高，G0/G1期细胞百分率显著下降，S期和G2/M期细胞百分率明显上升（P<0.05）；AO/EB检测，CdTe QDs作用后细胞出现凋亡形态学改变；Annexin Ⅴ-FITC/PI双荧光标记FCM法，CdTe QDs染毒可促进细胞凋亡，各剂量组细胞凋亡率与对照组比较差异有统计学意义（P<0.05）。结论：CdTe QDs可影响细胞存活，引起DNA损伤、细胞周期阻滞，并诱导细胞凋亡。

Induction of thioglycolic acid-capped cadmium selenide quantum dots on hepatotoxicity and DNA damage in human hepatic cells

Objective To investigate the hepatotoxicity and DNA damage induced by thioglycolic acid(TGA)-capped cadmium telluride(CdTe) quantum dots(QDs) in human hepatic cells HL-7702,and to provide experimental evidence for the toxicological research and safety evaluation.Methods The HL-7702 cells were divided into control group and CdTe QDs-treated groups with different concentrations of CdTe QDs(0,6.25,12.50,25.00 and 50.00 mg·L-1,respectively).After treated with CdTe QDs,the cell proliferation was measured by MTT assay,the DNA damage by single cell gel electrophoresis(SCGE),the cell cycle process by propidium iodide(PI)-flow cytometry(FCM) and the apoptosis by acridine orange/ethidium bromide(AO/EB) assay and Annexin Ⅴ-fluorescein isothiocyanate(FITC)/PI-FCM.Results The MTT results showed that CdTe QDs inhibited the proliferation of HL-7702 cells in a dose-dependent and time-dependent manner.The results acquired by SCGE and FCM with PI staining showed that after CdTe QDs exposure for 24 h,as exposure dose increased,the degree of DNA damage raised,and the percentage of HL-7702 cells in G0/G1 phase was decreased while they were significantly increased in S and G2/M phases(P<0.05).In AO/EB assay,the apoptotic cells were observed under fluorescence microscope;In Annexin Ⅴ-FITC/PI-FCM,the apoptotic rates in CdTe QDs groups were significantly increased compared with control group(P<0.05).Conclusion CdTe QDs could influence the cell viability,and induce DNA damage,S and G2/M phases arrest and apoptosis in HL-7702 cells.