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）包被的碲化镉（CdTe）量子点为研究对象，作用于体外培养的鼠神经元细胞（PC-12）。实验设立对照组和不同浓度CdTe QDs作用组。CdTe QDs作用于细胞后，采用倒置荧光显微镜分别观察量子点作用下的细胞形态与细胞对量子点的摄取情况；使用alamarBlue 检测CdTe QDs对细胞存活率的影响；Hoechst 33342 单染法观察CdTe QDs 对PC-12 细胞核形态的影响；Annexin V-FITC 单染检测CdTe QDs 对PC-12 细胞凋亡的影响。结果：CdTe 量子点作用后，低浓度实验组细胞变化不明显，高浓度实验组中的细胞的形态发生改变，引起细胞肿胀变圆，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：量子点与细胞接触后会通过胞吞途径进入细胞，汇聚于多种细胞器，对细胞器的功能造成损害，进而引发多种途径的细胞凋亡机制并引发细胞死亡。

英文摘要：

Objective： To investigate the biological security of CdTe QDs. Methods： CdTe QDs which was made by hydrothermal method and covered by MSA was chosen as the object. The cells were divided into control group and CdTe QDs-treated groups with different concentrations of CdTe QDs. Affected by CdTe QDs. The cell morphology and the fluorescence of CdTe QDs was observed by inverted fluorescence microscope. The cell survival rate was examined by alamarBlue, and cell apoptotic morphology in staining was detected by Hoechst 33342. The influence of CdTe QDs on the apoptosis of PC-12 was examined by Annexin V-FITC single-stain procedure. Results： Affected by CdTe QDs, cells in the experimental group treated with low concentration of CdTe QDs changed not obviously while the morphology of those treated with high concentration obviously changed. In addition, they swelled and became round, the number of which decreased, and the survival rate decreased significantly. It was obvious apoptosis in staining. Conclusions： We consider that quantum point contact with cells, will be uptaken into the cell, together in various organelle, damage the function of the organelle, cause various pathways of apoptosis mechanism and cause cell death at last.