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通过两步ATRP制备了两亲性p H响应性超支化星形共聚物HP(DMAESP-co-BS2MOE)-(POEGMA)n.首先,以2-(2’-溴异丙酰氧基)乙基2″-甲基丙烯酰氧基乙基二硫化物(BS2MOE)为自引发单体,与甲基丙烯酰氧基-3-硫代己酸二甲氨基乙酯(DMAESP)共聚,得到超支化共聚物HP(DMAESP-coBS2MOE).然后以HP(DMAESP-co-BS2MOE)作为大分子引发剂引发甲基丙烯酸寡聚乙二醇酯(OEGMA)的聚合,得到超支化星形共聚物HP(DMAESP-co-BS2MOE)(POEGMA)n.在DMAESP中,叔胺基团和甲基丙烯酸酯基团通过酸敏感的β-硫丙酯键连接,由于该键在酸性条件下能够缓慢水解,形成羧基末端,最终得到的聚合物具有p H响应性.同时,由于BS2MOE中含有二硫键,能够被细胞中的谷胱甘肽还原,该聚合物同时具有氧化还原响应性.HP(DMAESP-co-BS2MOE)(POEGMA)n在水中能够自组装成以HP(DMAESP-co-BS2MOE)为核,以POEGMA为壳的纳米级胶束,并能负载DNA,可作为基因转染的载体.
Amphiphilic p H-responsive hyperbranched star copolymer HP (DMAESP-co-BS2MOE) - (POEGMA) n was prepared by two-step ATRP. Radical 2 "-methacryloyloxyethyl disulfide (BS2MOE) is a self-initiated monomer copolymerized with dimethylaminoethyl methacryloyloxy-3-thiohexanoate (DMAESP) (DMAESP-coBS2MOE) .Polymerization of oligomeric ethylene glycol monomethacrylate (OEGMA) with HP (DMAESP-co-BS2MOE) as a macroinitiator was then initiated to give the hyperbranched star copolymer HP DMAESP-co-BS2MOE) (POEGMA) n. In DMAESP, the tertiary amine group and the methacrylate group are linked by an acid-sensitive β-thiolate bond due to the ability to slowly hydrolyze under acidic conditions to form Carboxy terminus, the resulting polymer has p H responsiveness and, at the same time, is reduced by glutathione in cells due to the disulfide bond present in BS2MOE, which has both redox responsiveness and HPP (DMAESP-co -BS2MOE) (POEGMA) n can self-assemble into nano-sized micelles with HP (DMAESP-co-BS2MOE) and POEGMA as shell in water and can be used as a vector for gene transfection.