Synthesis Of Amphiphilic Dendritic Polyester And Their Applications In Drug Releasing

Recently, the study of the biodegradable polymer drug delivery attracts more people's attention. The biodegradable polymer using as drug delivery can be degraded into water and carbon dioxide which were excreted body by metabolism; meantime, through control the degradation of the polymer materials, we can control the release of drugs. Polymer micelles can be formed through self-assemble of amphiphilic copolymer in aqueous environments. Polymer micelles as drug delivery can solubilize poorly water-soluble drugs in their inner core, decrease side effect. This article is focused on the synthesis and characterization of a novel biodegradable and amphiphilic dendritic polyester and using it as drug carrier. The research was mainly concerned with the following aspects:1. First, the glycolic acid oligomer and glycolic acid-lactic acid alternate oligomer were synthesized; the carboxyl group of the oligomer was protected by tert-butyl group. The structure was characterized by 1H NMR.2. In the presence of potassium bicarbonate in tetrahydrofuran, DMPA reacted with oligomer to synthesize the growing unit. The structure was characterized by 1H NMR.3. The growing units reacted with 4-Benzyloxy-4-oxobutanoic acid in order to protect the hydroxyl of DMPA. The carboxyl of the growing units was activated in the presence of TFA. The dendrimer was synthesized through convergence method, and their structures were confirmed by 1H NMR.4. The amphiphilic dendritic polymer was synthesized by condensation reaction of dendrimer and MPEG. The structure was characterized by 1H NMR, MALDI-TOF and GPC.5. Micelle with core-shell structure was prepared in aqueous solution from the amphiphilic block copolymers, and characterized by 1H NMR, TEM, DLS and fluorescence. The block copolymer micelle was loaded with the water-fast anticancer drug; paclitaxel was also characterized by TEM and DLS. The release of paclitaxel from mPEG5000-G3-Bn was monitored by UV-Vis which showed that the release was controlled by a combined degradation-diffusion mechanism.