College of Chemistry and Material Sciences, South-Central University for Nationalities, Wuhan 430074, PR China; State Key Laboratory of Virology & Key laboratory of Analytical Chemistry for Biology and Medicine (MOE), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China; Key Laboratory of Hubei Province for Coal Conversion and New Carbon Materials, College of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan 430081, PR China.
College of Chemistry and Material Sciences, South-Central University for Nationalities, Wuhan 430074, PR China.
Ecotoxicol Environ Saf. 2019 Jun 15;174:467-474. doi: 10.1016/j.ecoenv.2019.03.013. Epub 2019 Mar 7.
Cadmium (Cd)-based QDs are well studied owing to their excellent optical properties. The applications of Cd-based QDs in biomedical filed, however, is hindered by its inherent toxicity. In this study, to overcome the inherent toxicity of heavy metals, CdTe QDs were encapsulated with different shells (NAC, MPA and GSH) to reduce the leakage of Cd from the core. We studied the cytotoxicity of the three kinds of CdTe QDs on S. cerevisiae by spectroscopic, electrochemical, microscopic methods and microcalorimetric technique. Results showed that toxicity of CdTe QDs increased with the augment of QD concentration. According to the values of IC ((GSH-CdTe QDs (15.3 nmol/L) < MPA-CdTe QDs (56.2 nmol/L) < NAC-CdTe QDs (89.8 nmol/L)), the most toxic one is GSH-CdTe QDs, followed by MPA-CdTe QDs, then NAC-CdTe QDs. The coatings have contribution to their toxicity. The three kinds of QDs with the similar shape (sphere) can enter the cell by the clathrin-mediated endocytosis and lead to the different impairments. The mechanism of cytotoxicity is due to the release of Cd leading elevation of intracellular reactive oxygen species (ROS), which damage mitochondria. The clathrin-mediated endocytosis is a significant factor in determining the toxicity of CdTe QDs.
基于镉 (Cd) 的量子点由于其优异的光学性质而得到了广泛研究。然而，由于其固有毒性，基于 Cd 的量子点在生物医学领域的应用受到了限制。在本研究中，为了克服重金属的固有毒性，将 CdTe 量子点用不同的壳层（NAC、MPA 和 GSH）包裹，以减少核心中 Cd 的泄漏。我们通过光谱学、电化学、显微镜方法和微量热技术研究了三种 CdTe 量子点对酿酒酵母的细胞毒性。结果表明，量子点浓度的增加会导致 CdTe 量子点的毒性增加。根据 IC 值（(GSH-CdTe QDs（15.3 nmol/L）< MPA-CdTe QDs（56.2 nmol/L）< NAC-CdTe QDs（89.8 nmol/L）），毒性最大的是 GSH-CdTe QDs，其次是 MPA-CdTe QDs，然后是 NAC-CdTe QDs。涂层对其毒性有贡献。这三种形状相似（球形）的量子点可以通过网格蛋白介导的内吞作用进入细胞，并导致不同的损伤。细胞毒性的机制是由于 Cd 的释放导致细胞内活性氧（ROS）水平升高，从而损伤线粒体。网格蛋白介导的内吞作用是决定 CdTe 量子点毒性的重要因素。
