Synthesis And Characterization Of Novel Amphiphilic Dendritic Polyether-ester

Polyester dendrimers not only possess controlled size and structure, and manysurface-end groups like other dendrimers but also own intrinsic properties such asnonimmunogenicity, good biocompatibility, and biodegradability derived frompolyester backbone. Consequently, these dendrimers may be widely used inbiomedical applications, including sutures, scaffolds in tissue engineering, andcarriers in drug delivery. Polyether-ester dendrimer is a kind of novel polyesterdendrimer that degrades quickly because of the increased hydrolytic susceptibility ofthe polyester-ether backbone compared to the polyester dendrimer. These propertiesare likely to facilitate the design and development of new materials, which providenew opportunities to create well-defined, tailored polymers for specific medical andtissue engineering applications.In the present study, novel polyether-ester dendrons and their amphiphiliccopolymers were synthesized and characterized. The self-assembly behavior ofamphiphilic dendritics in aqueous environment was also investigated. The maincontents were as follows:1. First, a branching AB2monomer unit composed of glycerol and glycolic acidwas synthesized by a facile synthetic method. The structure was confirmedby proton nuclear magnetic resonance (1H NMR) spectra, carbon-13nuclearmagnetic resonance (13C NMR) spectra and Gas chromatography massspectrometry (GC-MS.)2. Moreover, a novel acid-terminated G3polyether-ester dendron wassynthesized by sequential esterification and deprotection reactions. Thestructure was confirmed by1H NMR spectra,13C NMR spectra, andtime-of-flight mass spectrometry (MALDI-TOF-MS).3. Glycolic acid oligomers was introduced into monomer unit to increase thevariability of dendrons, and a carboxyl-terminated G3polyether-esterdendron composed of glycerol and glycolic acid oligomers was synthesizedand characterized.4. Amphiphilic dendritic polyether-esters were synthesized by dicyclohexyl-carbodiimide (DCC) condensation reaction of MPEG with twocarboxyl-terminated G3polyether-ester dendrons respectively. The structuresof the products were confirmed by1H NMR, MALDI-TOF-MS and gel permeation chromatography(GPC). Moreover, amphiphilic dendriticpolyether-esters micelles was prepared in aqueous solution and characterizedby fluorescence and dynamic light scattering.