Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München, Munich 81377, Germany.
Biomaterials. 2010 Sep;31(26):6692-700. doi: 10.1016/j.biomaterials.2010.05.051. Epub 2010 Jun 17.
The increasing interest in biomedical applications of semiconductor quantum dots (QDs) is closely linked to the use of surface modifications to target specific sites of the body. The immense surface area of vascular endothelium is a possible interaction platform with systemically administered QDs. Therefore, the aim of this study was to investigate the microvascular distribution of neutral, cationic, and anionic QDs in vivo. QDs with carboxyl-, amine- and polyethylene glycol surface coatings were injected into the blood circulation of mice. In vivo microscopy of the cremaster muscle, two-photon microscopy of skeletal and heart muscle, as well as quantitative fluorescence measurements of blood, excreta, and tissue samples were performed. Transmission electron microscopy was used to detect QDs at the cellular level. The in vitro association of QDs with cultured endothelial cells was investigated by flow cytometry and confocal microscopy. Anionic QDs exhibited a very low residence time in the blood stream, preferably accumulated in organs with a prominent mononuclear phagocytic component, but were also found in other tissues with low phagocytic properties where they were predominantly associated with capillary endothelium. This deposition behavior was identified as a new, phagocyte-independent principle contributing to the rapid clearance of anionic QDs from the circulation.
人们对半导体量子点（QD）在生物医学方面应用的兴趣日益浓厚，这与利用表面修饰来靶向体内特定部位密切相关。血管内皮的巨大表面积可能是与全身给予的 QD 相互作用的平台。因此，本研究的目的是研究体内中性、阳离子和阴离子 QD 的微血管分布。将具有羧基、胺基和聚乙二醇表面涂层的 QD 注射到小鼠的血液循环中。对提睾肌进行活体显微镜检查，对骨骼和心肌进行双光子显微镜检查，以及对血液、排泄物和组织样本进行定量荧光测量。透射电子显微镜用于在细胞水平检测 QD。通过流式细胞术和共聚焦显微镜研究了 QD 与培养的内皮细胞的体外结合。阴离子 QD 在血流中的停留时间非常短，更喜欢积聚在单核吞噬细胞成分明显的器官中，但也存在于其他吞噬特性低的组织中，它们主要与毛细血管内皮结合。这种沉积行为被确定为一种新的、与吞噬细胞无关的原则，有助于阴离子 QD 从循环中快速清除。
