中文摘要：

目的探讨碲化镉（CdTe）量子点的生物安全性。方法以水热法制备的、巯基丁二酸（MSA）包被的CdTe量子点为研究对象，作用于体外培养的A549细胞。实验设立对照组和不同浓度CdTe量子点作用组。CdTe量子点作用于细胞后，采用倒置荧光显微镜观察量子点作用下的细胞形态；使用alamar Blue检测CdTe量子点对细胞存活率的影响；使用Hoechst 33342单染法观察CdTe量子点对A549细胞核形态的影响；使用Annexin V—FITC单染法检测CdTe量子点对A549细胞凋亡的影响。结果CdTe量子点作用后，低浓度（2．5，5，10mg／L）实验组细胞变化不明显，高浓度实验组（25，50mg／L）中的细胞肿胀变圆，细胞数量减少；存活率显著下降；在染色下可见明显的细胞凋亡。结论MSA包被的CdTe量子点在达到一定浓度后对A549细胞有较强的毒性。这可能与量子点的纳米特性、CdTe的金属化合物毒性有关。

英文摘要：

Objective It is to approach the biological security of CdTe QDs. Methods CdTe QDs which was made by hydrothermal method and covered by Mercapto succinic acid （MSA） was chosen as the object. The cells were divided into control group and CdTe QDs - treated groups with different concentrations of CdTe QDs. Afler affected by CdTe QDs, the morphology of A549 cells was observed by inverted fluorescence microscope. The cell survival rate was examined by alamarBlue, and nuclear morphology in staining was detected by Hoechst 33342. The influence of CdTe QDs on the apoptosis of A549 was examined by Annexin V - FITC single-stain procedure. Results Quantum dots carl inhibit the proliferation of A549 cell in a dose-dependent manner. QDs of different concentrations will induce apoptosis in different degree. Conclusion CdTe QDs coated with MSA has strong toxicity to A549 cells in certain concentration. This may be related to nano characteristics of quantum dots and the metal toxicity of CdTe.