Differences in subcellular distribution and toxicity of green and red emitting CdTe quantum dots
Differences in subcellular distribution and toxicity of green and red emitting CdTe quantum dots
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DOI：
10.1007/s00109-004-0629-x
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发表时间：
2005-05-01
影响因子：
4.7
通讯作者：
Maysinger, D
中科院分区：
文献类型：
--
作者：
Lovric, J;Bazzi, HS;Maysinger, D
量子点（QDs）正在成为生物成像中有机荧光染料的替代或补充工具。与传统荧光染料相比，量子点具有几个优点，包括更高的光稳定性和更宽的激发/发射波长范围。然而，最近的研究表明，量子点对细胞过程产生有害影响。本研究探讨了碲化镉量子点的亚细胞定位和毒性，以及防止量子点诱导的细胞死亡的药理学方法。发现CdTe量子点的定位取决于量子点的大小。CdTe量子点在PC12和N9细胞中表现出明显的细胞毒性，浓度低至10 μ g/ml。qd诱导的细胞死亡以染色质凝结和膜泡为特征，较小的（2r=2.2 +/- 0.1 nm）绿色发光带正电荷的量子点比较大（2r=5.2 +/- 0.1 nm）带等电荷的红色发光量子点更明显。用抗氧化剂n -乙酰半胱氨酸和牛血清白蛋白预处理细胞，而不使用Trolox，可显著降低qd诱导的细胞死亡。这些发现表明，量子点的大小决定了它们的亚细胞分布，药物可以改变量子点诱导的细胞毒性。
Quantum dots (QDs) are emerging as alternative or complementary tools to the organic fluorescent dyes currently used in bioimaging. QDs hold several advantages over conventional fluorescent dyes including greater photostability and a wider range of excitation/emission wavelengths. However, recent work suggests that QDs exert deleterious effects on cellular processes. This study examined the subcellular localization and toxicity of cadmium telluride (CdTe) QDs and pharmacological means of preventing QD-induced cell death. The localization of CdTe QDs was found to depend upon QD size. CdTe QDs exhibited marked cytotoxicity in PC12 and N9 cells at concentrations as low as 10 mu g/ml in chronic treatment paradigms. QD-induced cell death was characterized by chromatin condensation and membrane blebbing and was more pronounced with small (2r=2.2 +/- 0.1 nm), green emitting positively charged QDs than large (2r=5.2 +/- 0.1 nm), equally charged red emitting QDs. Pretreatment of cells with the antioxidant N-acetylcysteine and with bovine serum albumin, but not Trolox, significantly reduced the QD-induced cell death. These findings suggest that the size of QDs contributes to their subcellular distribution and that drugs can alter QD-induced cytotoxicity.