Lactoferrin Conjugated with Quantum Dots to MC3T3-E1 Cell Endosome labelling

• Main Authors: Yung-Han Fang, 方詠涵
• Other Authors: Walter H. Chang
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/33699370126426489673

碩士 === 中原大學 === 醫學工程研究所 === 94 === In this study, the multifunctional Lactoferrin(LF) was conjugated with quantum dot (QD) that have greater and longer fluorescence. Because LF can induce receptor-mediated endocytosis of cell, so the LF of QD and LF complexes (QD-LF) were used to induce cell endocytosis and bring QD-LF into intracellular endosome. Then the distribution of endosome and LF could be monitored by detecting the fluorescence of QD. The purpose of this study was to find the best conjugated conditions of QD and LF without losing LF its own function. First of all, polymer coating method was used to modify hydrophobic QD becoming hydrophilic QD. Then the reaction surrounding was modified by controlling reactant concentrations and linker numbers for forming covalent bind of QD and LF. After that, the results of conjugation were determined based on optical property, electrophoresis analysis, and incubated with MC3T3-E1 cell directly. In addition, this polymeric QD surface was modified by conjugating different functional group and length of poly(ethylene glycol) (PEG), and was attempted to reduce nonspecific binding problem of QD. The results of conjugated experiment of QD and LF showed that when the ratio of QD to LF is 1:2, the QD-LF that only have several LF on the surface of QD was obtained. And when the ratio of QD to LF is 1:25, the linker numbers of conjugated conditions were modulated. The products of conjugated QD with LF under this condition had unity size and electric charges. In the cell uptake experiment, there was distribution of granular QD in the cytoplasm. Because of this phenomenon, it was conjectured that QD was uptake by receptor-mediated endocytosis of cell. And QD really labeled the endosome. In addition, in the experiment of PEG conjugated with QD, the nonspecific binding was reduced and the salt stability of polymeric QD was increased by PEG-QD.