Laboratoire Physique et Etude des Matériaux UMR8213, ESPCI ParisTech-CNRS - UPMC Sorbonne Universités, 10 rue Vauquelin, 75005 Paris, France.
Small. 2012 Apr 10;8(7):1029-37. doi: 10.1002/smll.201101787. Epub 2012 Feb 29.
The in vivo labeling of intracellular components with quantum dots (QDs) is very limited because of QD aggregation in the cell cytoplasm and/or QD confinement into lysosomal compartments. In order to improve intracellular targeting with QDs, various surface chemistries and delivery methods have been explored, but they have not yet been compared systematically with respect to the QD intracellular stability. In this work, the intracellular aggregation kinetics of QDs for three different surface chemistries based on ligand exchange or encapsulation with amphiphilic polymers are compared. For each surface chemistry, three delivery methods for bringing the nanoparticles into the cells are compared: electroporation, microinjection, and pinocytosis. It is concluded that the QD intracellular aggregation behavior is strongly dependent on the surface chemistry. QDs coated with dihydrolipoic acid-sulfobetaine (DHLA-SB) ligands diffuse freely in cells for longer periods of time than for QDs in the other chemistries tested, and they can access all cytoplasmic compartments. Even when conjugated to streptavidin, these DHLA-SB QDs remain freely diffusing inside the cytoplasm and unaggregated, and they are able to reach a biotinylated target inside HeLa cells. Such labeling was more efficient when compared to commercial streptavidin-conjugated QDs, which may be due to the smaller size of DHLA-SB QDs and/or to their superior intracellular stability.
量子点（QD）在细胞内成分的体内标记非常有限，因为 QD 在细胞质中聚集和/或 QD 被限制在溶酶体隔室中。为了提高 QD 的细胞内靶向性，已经探索了各种表面化学和输送方法，但尚未就 QD 的细胞内稳定性对它们进行系统比较。在这项工作中，比较了基于配体交换或两亲聚合物包封的三种不同表面化学的 QD 的细胞内聚集动力学。对于每种表面化学，比较了将纳米颗粒带入细胞的三种输送方法：电穿孔、显微注射和胞吞作用。结果表明，QD 的细胞内聚集行为强烈依赖于表面化学。用二氢硫辛酸-磺基甜菜碱（DHLA-SB）配体涂覆的 QD 在细胞内扩散的时间比其他测试的化学物质中的 QD 长，并且可以进入所有细胞质隔室。即使与链霉亲和素偶联，这些 DHLA-SB QD 仍然在细胞质内自由扩散且不聚集，并能够到达 HeLa 细胞内的生物素化靶标。与商业链霉亲和素偶联的 QD 相比，这种标记效率更高，这可能是由于 DHLA-SB QD 的尺寸更小和/或其更好的细胞内稳定性。
