Dynamics and mechanisms of quantum dot nanoparticle cellular uptake

Journal of Nanobiotechnology

Research

Samuel P Forry¹  Yan Xiao¹  R David Holbrook¹  Alessandro Tona²  William G Telford³  Xiugong Gao⁴ 

[1] Chemical Science and Technology Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, USA;Chemical Science and Technology Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, USA;Science Applications International Corporation (SAIC), Arlington, VA, USA;Experimental Transplantation and Immunology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA;Research and Development, Translabion, Clarksburg, MD, USA;

关键词: Cellular Uptake;    Early Endosome;    Live Cell Microscopy;    Flat Field Image;    Violet Laser Diode;   

DOI  :  10.1186/1477-3155-8-13

 received in 2010-03-05, accepted in 2010-06-15,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundThe rapid growth of the nanotechnology industry and the wide application of various nanomaterials have raised concerns over their impact on the environment and human health. Yet little is known about the mechanism of cellular uptake and cytotoxicity of nanoparticles. An array of nanomaterials has recently been introduced into cancer research promising for remarkable improvements in diagnosis and treatment of the disease. Among them, quantum dots (QDs) distinguish themselves in offering many intrinsic photophysical properties that are desirable for targeted imaging and drug delivery.ResultsWe explored the kinetics and mechanism of cellular uptake of QDs with different surface coatings in two human mammary cells. Using fluorescence microscopy and laser scanning cytometry (LSC), we found that both MCF-7 and MCF-10A cells internalized large amount of QD655-COOH, but the percentage of endocytosing cells is slightly higher in MCF-7 cell line than in MCF-10A cell line. Live cell fluorescent imaging showed that QD cellular uptake increases with time over 40 h of incubation. Staining cells with dyes specific to various intracellular organelles indicated that QDs were localized in lysosomes. Transmission electron microscopy (TEM) images suggested a potential pathway for QD cellular uptake mechanism involving three major stages: endocytosis, sequestration in early endosomes, and translocation to later endosomes or lysosomes. No cytotoxicity was observed in cells incubated with 0.8 nM of QDs for a period of 72 h.ConclusionsThe findings presented here provide information on the mechanism of QD endocytosis that could be exploited to reduce non-specific targeting, thereby improving specific targeting of QDs in cancer diagnosis and treatment applications. These findings are also important in understanding the cytotoxicity of nanomaterials and in emphasizing the importance of strict environmental control of nanoparticles.

【 授权许可】

CC BY   
© Xiao et al; licensee BioMed Central Ltd. 2010