Aqueous-Phase Synthesis of Highly Luminescent CdTe/ZnTe Core/Shell Quantum Dots Optimized for Targeted Bioimaging
Aqueous-Phase Synthesis of Highly Luminescent CdTe/ZnTe Core/Shell Quantum Dots Optimized for Targeted Bioimaging
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DOI：
10.1002/smll.200801555
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发表时间：
2009-06-05
期刊：
影响因子：
13.3
通讯作者：
Prasad, Paras N.
中科院分区：
文献类型：
--
作者：
Law, Wing-Cheung;Yong, Ken-Tye;Prasad, Paras N.
半导体量子点（QD）传统上是在有机相中合成的，并通过用二氧化硅、聚合物、短链硫醇配体或磷脂胶束对其表面进行官能化而转移到水溶液中。然而，这些复杂的步骤导致i）QD的量子产率（QY）的降低，ii）QD的部分降解，以及iii）QD的流体动力学尺寸的急剧增加，这可能阻碍它们的生物医学应用。在这项工作中，半胱氨酸封端的CdTe/ZnTe量子点，这是直接在水介质中合成，作为在体外特异性靶向胰腺癌和食管癌细胞的光学探针的制备和应用，以及它们的在体内成像的能力。CdTe/ZnTe量子点是在一锅法中合成的，并用氨基酸半胱氨酸封端，半胱氨酸在其表面上含有羧基和胺官能团用于生物缀合。所制备的量子点具有超小的流体动力学直径（3-5 nm），具有高QY（52%），并且在实验剂量下对细胞无毒。共聚焦成像用于证明受体介导的抗体缀合的QD摄取到体外胰腺癌细胞中。体外细胞毒性研究（MTS-测定）表明，这些QD的IC 50值约为160 μ g/mL（-1），表明毒性低。此外，QD用于小动物成像，其中研究这些QD的体内生物相容性及其在全身注射后的清除。
Semiconductor quantum dots (QDs) have traditionally been synthesized in organic phase and transferred to aqueous solution by functionalizing their surface with silica, polymers, short-chain thiol ligand, or phospholipid micelles. However, these complex steps result in i) a reduction of the quantum yield (QY) of QDs, ii) partial degrdation of the QDs, and iii) a drastic increase in the hydrodynamic size of QDs, which may hinder their biomedical applications. In this work, the fabrication and applications Of cysteine-capped CdTe/ZnTe QDs, which are directly synthesized in aqueous media, as optical probes for specific targeting of pancreatic and esophageal cancer cells in vitro are reported, as well as their capability for in vivo imaging. The CdTe/ZnTe QDs are synthesized in a one-pot method and capped with amino acid cysteine, which contains both carboxyl and amine functional groups on their surfaces for bioconjugation. The fabricated QDs have an ultrasmall hydrodynamic diameter (3-5 nm), possess high QY (52%), and are non-toxic to cells at experimental dosages. Confocal imaging is used to demonstrate a receptor-mediated uptake of antibody-conjugated QDs into pancreatic cancer cells in vitro. In vitro cytotoxicity studies (MTS-assay) show that the IC50 value of these QDs is approximate to 160 mu g mL(-1), demonstrating low toxicity. In addition, the QDs are used for small-animal imaging where the in vivo biocompatiblity of these QDs and their clearance following systemic injection is studied.