dc.description.abstract | The major purposes of this study are to investigate the alternation of fluorescent properties, the salt enduribility in physiological environment and the effects of endocytosis of various animal cells after different water soluble treatments of semiconductor nanocrystals CdSe/ZnS core/shell quantum dots (QDs). This work begun with comparing the QDs mass recoveries, relative quantum yields, and salt stabilities in salt-containing buffers after surfaces modification with mercapto-carbonic acids including mercaptopropionic acid (MPA) and mercapto-undecanoic acid (MUA), amphiphilic polymer, poly(maleic anhydride alt-1-tetradecene) (PMATD) and phospholipids, (1,2-disteraroyl-sn-glycero-3-phospho- ethanolamine-N-[amino(polyethylene glycol)2000])(DSPE-PEG). It was found that the phospholipids encapsulated water-soluble QDs revealed highest mass recovery about 80 % and MPA treated QDs had greatest relative quantum yield up to 200 %. And these modified QDs displayed remarkable salt stabilities at the physiological environment like 100 mM to 200 mM NaCl contained solutions. It was deserve to be mentioned that the phospholipids-encapsulated QDs showed the best salt enduriblity without any observable agglomeration, even though the NaCl concentration was raised up to 400 mM.
In the following, the water-soluble QDs with various surface modification were co-cultured with Human foreskin fibroblast and keratinocyte, CCD 1106 KERTr., in order to realized the endocytosis process of QDs into the animal cells. Our results showed that the keratinocytes could be easily targeted by water-soluble QDs, however, QDs could not be uptake by fibroblast. Therefore, recombinant human fibroblast growth factor-basic (b-FGF) and monoclonal mouse anti-FGF receptor (anti-FGF receptor) were covalently conjugated to PMATD-encapsulated QDs in the presence of activation reagents. Our results demonstrated that the anti-FGF receptor conjugated QDs were uptaked into the fibroblast after the incubation of receptor-labeled QDs and fibroblasts, furthermore, the b-FGF bound QDs could attach to the FGF receptors located at fibroblast cell surfaces. As mentioned above, different uptaking behaviors of fibroblasts and keratinocytes were exhibition toward the same surface-treated QDs, and the features allowed us for generally labeling or staining of living cells with QDs which could be uptake inside the cells, or allowed us for specifically labeling a cellular target on cell surfaces with QDs which could not be uptake inside the cells. | en_US |