Dendrimers are highly branched polymer with high density of surface functionality and core cavities. The unique architecture of dendrimers contributes to many medical application. The surface electricity of dendrimers is defined as cationic, anionic and neutral due to the functional group, amine, carboxyl and hydroxyl. The internalization of drug/gene carriers is highly interesting because it is important for designing a suitable drug/gene carrier. In this study, several endocytotic inhibitors were used to investigate the influence of surface electricity on internalization of poly (amidoamine) (PAMAM) dendrimers, and confirmed the cellular distribution of dendrimers in the presense of various endocytotic inhibitors by confocal laser scanning microscopy. The results indicate that the cellular uptakes of different PAMAM dendrimers were obviously influenced of surface functionality on the internalizations. Cationic dendrimer was shown the highest uptake by HeLa cells, while the anionic and neutral was shown rarely enter the cells. The further studies on internalization of cationic dendrimer provide a method to investigate the detail process of the attachment and further endocytosis of particle. Understanding the internalization of dendrimers may contribute to develop the modification designing for desired applications and targeting cells.1. Intruductoin……………………………………………………….………………... 1. Materials and Methods………….………………………………………………... 3.1 Chemicals and Materials…………………………………………………… 4.2 Materials for Cell Culture…………………………………………………... 5.3 Synthesis of fluorecently labeled generation 4 PAMAM-NH2 dendrimers…7.4 Synthesis of fluorecently labeled generation 4 PAMAM-OH dendrimers…. 7.5 Synthesis of fluorecently labeled generation 3.5 PAMAM-COOHendrimer…………………………………………………………………… 9.6 Cell culture…………………………………………….………………….. 10.7 Cell uptake and Inhibition studies……………………………………….... 10.8 Internalization studies………………………………………….………….. 11.9 FACS analysis……………………………………….…….……………… 12.10 Confocal laser scanning microscopy………..…………..………………… 13.11 Fluorescence microscopy studies………………………….….…………... 13. Results…………………………………………….………………………………. 15.1 Purification and fluorescence spectrum of fluorescently labeledendrimers………………………………………………………………… 15.2 Time-course cellular uptake of fluorescently labeled dendrimers………… 15.3 Effect of low temperature blocked cellular uptake……………….……….. 16.4 Influence of surface electricity and endocytotic inhibitors on cellularptake…………………………………………………………………….... 17.5 Internalization and attachment studies of dendrimer with highest uptake ofhree………………………..….…………………………….…………….. 20. Discussions………………………………………….………………………......... 23. Conclusion………………………………………………………….…………….. 33amp;#63851;考文獻…………………………………………………………….……….……….. 34錄……………………………………………………….…………………………... 4
