writer：Sun, X. Y.; Zhou, Y. F.*; Yan, D. Y.*
keywords：hyperbranched polymers, double-hydrophilic copolymer, polyglycerol, ATRP, drug delivery
source：期刊
specific source：Sci. China Ser. B-Chem. 2009, 52, 1703. http://link.springer.com/article/10.1007/s11426-009-0227-4
Issue time：2009年
In this paper, we report the synthesis and self-assembly of double-hydrophilic hyperbranched graft copolymers of HPG-g-PDMAEMA, which consist of a hyperbranched polyglycerol (HPG) core and several grafted poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) arms. HPG was synthesized by cationic polymerization. Then HPG-Br macroinitiator was obtained by esterification of HPG with 2-bromoisobutyryl bromide, which was subsequently used in the preparation of HPG-g-PDMAEMA graft copolymers through atom transfer radical polymerization (ATRP) of DMAEMA monomers. The molecular structures were studied by ¹H NMR and GPC. The pyrene-based fluorescent probe method, ¹H NMR and DLS were used to study the self-assembly behavior of HPG-g-PDMAEMA. The drug loading and pH-responsive release properties of HPG-g-PDMAEMA were also investigated by using coumarin 102 as a model drug. The results show that the HPG-g-PDMAEMA micelles can continuously release and re-encapsulate coumarin 102 as the pH continuously changes from 11.5 to 2.5; however, this process is not totally reversible.