In vivo biodistribution and behavior of CdTe/ZnS quantum dots

Yan Zhao,1,* Yue Zhang,2,* Gaofeng Qin,1 Jinjun Cheng,1 Wenhao Zeng,2 Shuchen Liu,1 Hui Kong,1 Xueqian Wang,1 Qingguo Wang,1 Huihua Qu3 1School of Basic Medical Sciences, 2School of Chinese Materia Medica, 3Center of Scientific Experiment, Beijing University of Chinese Medicine, Beijing, People’s Republic of China *These authors contributed equally to this work Abstract: The unique features of quantum dots (QDs) make them desirable fluorescent tags for cell and developmental biology applications that require long-term, multitarget, and highly sensitive imaging. In this work, we imaged fluorescent cadmium telluride/zinc sulfide (CdTe/ZnS) QDs in organs, tissues, and cells, and analyzed the mechanism of their lymphatic uptake and cellular distribution. We observed that the fluorescent CdTe/ZnS QDs were internalized by lymph nodes in four cell lines from different tissue sources. We obtained the fluorescence intensity–QD concentrations curve by quantitative analysis. Our results demonstrate that cells containing QDs can complete mitosis normally and that distribution of QDs was uniform across cell types and involved the vesicular transport system, including the endoplasmic reticulum. This capacity for CdTe/ZnS QD targeting provides insights into the applicability and limitations of fluorescent QDs for imaging biological specimens. Keywords: quantum dots, lymph nodes, fluorescence imaging, biodistributio