Institute of Applied Physics and Center for Functional Nanostructures, Karlsruhe Institute of Technology, Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany.
Nanoscale. 2013 Feb 21;5(4):1537-43. doi: 10.1039/c2nr33147k.
We have studied cellular uptake of ultrasmall fluorescent gold nanoclusters (AuNCs) by HeLa cells by confocal fluorescence microscopy in combination with quantitative image analysis. Water solubilized, lipoic acid-protected AuNCs, which had an overall hydrodynamic diameter of 3.3 nm and emitted fluorescence in the near-infrared region at ∼700 nm, were observed to accumulate on the cell membrane prior to internalization. The internalization mechanisms were analyzed using inhibitors known to interfere with specific pathways. Cellular uptake of AuNCs is energy-dependent and involves multiple mechanisms: clathrin-mediated endocytosis and macropinocytosis appear to play a significant role, whereas the caveolin-mediated pathway contributes only to a lesser extent. Co-labeling of different cell organelles showed that intracellular trafficking of AuNCs mainly follows through endosomal pathways. The AuNCs were ultimately transferred to lysosomes; they were completely excluded from the nucleus even after 24 h.
我们通过共聚焦荧光显微镜结合定量图像分析研究了 HeLa 细胞对超小荧光金纳米簇（AuNCs）的细胞摄取。水溶性、巯基乙酸保护的 AuNCs 的整体水动力直径为 3.3nm，在近红外区域发射约 700nm 的荧光，在被内化之前被观察到聚集在细胞膜上。使用已知可干扰特定途径的抑制剂分析内化机制。AuNCs 的细胞摄取是能量依赖性的，并涉及多种机制：网格蛋白介导的内吞作用和巨胞饮作用似乎起着重要作用，而小窝蛋白介导的途径则贡献较小。对不同细胞细胞器的共标记显示，AuNCs 的细胞内转运主要通过内体途径进行。AuNCs 最终被转运到溶酶体；即使在 24 小时后，它们也完全被排除在核外。
