Endo- and Exocytosis of Zwitterionic Quantum Dot Nanoparticles by Live HeLa Cells

详细信息    查看全文

• 作者：Xiue Jiang ; Carlheinz Röcker ; Margit Hafner ; Stefan Brandholt ; René M. Dörlich ; G. Ulrich Nienhaus
• 刊名：ACS Nano
• 出版年：2010
• 出版时间：November 23, 2010
• 年：2010
• 卷：4
• 期：11
• 页码：6787-6797
• 全文大小：671K
• 年卷期：0
• ISSN：1936-086X

文摘

Uptake and intracellular transport of D-penicillamine coated quantum dots (DPA-QDs) of 4 nm radius by live HeLa cells have been investigated systematically by spinning disk and 4Pi confocal microscopies. Unlike larger nanoparticles, these small DPA-QDs were observed to accumulate at the plasma membrane prior to internalization, and the uptake efficiency scaled nonlinearly with the nanoparticle concentration. Both observations indicate that a critical threshold density has to be exceeded for triggering the internalization process. By using specific inhibitors, we showed that DPA-QDs were predominantly internalized by clathrin-mediated endocytosis and to a smaller extent by macropinocytosis. Clusters of DPA-QDs were found in endosomes, which were actively transported along microtubules toward the perinuclear region. Later on, a significant fraction of endocytosed DPA-QDs were found in lysosomes, while others were actively transported to the cell periphery and exocytosed with a half-life of 21 min.