Atomic Force Microscopy-based Cell Nanostructure for Ligand-conjugated Quantum Dot Endocytosis  

作　　者：Yun-Long PAN Ji-Ye CAI Li QIN Hao WANG 

机构地区：[1]The First Affiliated Hospital of Jinan University, Guangzhou 510632, China [2]College of Life Science and Technology, Jinan University. Guangzhou 510632, China [3]Department of Histology and Embryology. Medical College of Jinan University, Guangzhou 510632, China [4]School for Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510631, China

出　　处：《Acta Biochimica et Biophysica Sinica》2006年第9期646-652,共7页生物化学与生物物理学报（英文版）

基　　金：supported by the grants from the Major State Basic Research Development Program of China(2001CB510101);the National Natural Science Foundation of China(No.30230350,60278014 and 60578025);the Doctor Innovation Fund of Jinan University

摘　　要：While it has been well demonstrated that quantum dots （QDs） play an important role in biological labeling both in vitro and in vivo, there is no report describing the cellular nanostructure basis of receptor-mediated endocytosis. Here, nanostructure evolution responses to the endocytosis of transferrin （Tf）-conjugated QDs were characterized by atomic force microscopy （AFM）. AFM-based nanostructure analysis demonstrated that the Tf-conjugated QDs were specifically and tightly bound to the cell receptors and the nanostructure evolution is highly correlated with the cell membrane receptor-mediated transduction. Consistently, confocal microscopic and flow cytometry results have demonstrated the specificity and dynamic property of Tf-QD binding and internalization. We found that the internalization of Tf-QD is linearly related to time. Moreover, while the nanoparticles on the cell membrane increased, the endocytosis was still very active, suggesting that QD nanoparticles did not interfere sterically with the binding and function of receptors. Therefore, ligand-conjugated QDs are potentially useful in biological labeling of cells at a nanometer scale.While it has been well demonstrated that quantum dots （QDs） play an important role in biological labeling both in vitro and in vivo, there is no report describing the cellular nanostructure basis of receptor-mediated endocytosis. Here, nanostructure evolution responses to the endocytosis of transferrin （Tf）-conjugated QDs were characterized by atomic force microscopy （AFM）. AFM-based nanostructure analysis demonstrated that the Tf-conjugated QDs were specifically and tightly bound to the cell receptors and the nanostructure evolution is highly correlated with the cell membrane receptor-mediated transduction. Consistently, confocal microscopic and flow cytometry results have demonstrated the specificity and dynamic property of Tf-QD binding and internalization. We found that the internalization of Tf-QD is linearly related to time. Moreover, while the nanoparticles on the cell membrane increased, the endocytosis was still very active, suggesting that QD nanoparticles did not interfere sterically with the binding and function of receptors. Therefore, ligand-conjugated QDs are potentially useful in biological labeling of cells at a nanometer scale.

关 键 词：quantum dot ENDOCYTOSIS NANOSTRUCTURE atomic force microscopy 

分 类 号：Q2[生物学—细胞生物学]