基于环糊精星形聚合物温度/pH双敏感超分子胶束的制备及性能研究

Preparation and Property of Temperature/pH Dual-responsive Supramolecular Micelles

通过原子转移自由基聚合方法制备了温度敏感性环糊精-聚N-异丙基丙烯酰胺星形聚合物(β-CD-(PNIPAM)7);以苯并咪唑(BM)修饰聚乙二醇(PEG-OH)得到苯并咪唑-聚乙二醇(BM-PEG).利用环糊精与苯并咪唑之间的主—客体识别作用,在37℃条件下,β-CD-(PNIPAM)7和BM-PEG在水溶液中自组装得到以PNIPAM为核、PEG为壳的温度/pH双敏感超分子胶束.以阿霉素(DOX)为模型药物,研究了超分子胶束的载药及释药性能.结果表明,超分子胶束呈现较为规则的空心结构,粒径在30~100 nm,分散性较好,对药物具有较高的载药量和包封率,分别为41.70%和71.54%,药物释放速率随溶液的pH减小而增大,随温度的降低而增大,表现出良好的环境响应性.

Temperature sensitive cyclodextrin-poly(N-isopropylacrylamide)star-shape polymer(β-CD-(PNIPAM)7)was prepared by atom transfer radical polymerization,and benzimidazole-polyethylene glycol(BM-PEG)was obtained by modifying polyethylene glycol(PEG-OH)with benzimidazole(BM).Using the host-guest recognition between cyclodextrin and benzimidazole group,a temperature and pH sensitive supramolecular micelle with PNIPAM as the core and PEG as the shell was prepared in aqueous solution at 37℃.Doxorubicin(DOX)was used as a model drug to study the drug loading and release properties of supramolecular micelles.The results indicate that the supermolecular micelles have regular hollow structure with 30~100 nm diameter and good dispersivity.In addition,the drug-loading content and entrapment efficiency of polymer micelles were 41.70%and 71.54%,respectively.The drug release rate increases with the decrease of pH value and temperature,showing good environmental responsiveness.