中文摘要：

采用原子转移自由基聚合（ATRP）方法合成了水溶性良好的不同聚合度的三嵌段共聚物P（DEAEMA-co-MEO，MA-co-HMAM）-b-PEG-b-P（DEAEMA-CO-MEO2MA-co-HMAM）．利用傅里叶变换红外光谱（FT-IR）、核磁共振氢谱（1HNMR）以及凝胶渗透色谱（GPC）对聚合物结构及组成进行表征；通过透光率、表面张力的测定以及动态光散射（DLS）、荧光探针和透射电镜（TEM）技术研究了共聚物水溶液的性质及胶束化行为．通过对不同pH下共聚物的凝胶状态和不同pH下温度诱导的溶胶-凝胶转变过程的观察，研究了温度和pH对共聚物凝胶化行为的影响．测定了载药凝胶分别在不同温度和不同pH的缓冲溶液中对药物的累积释放率．结果表明：ABA型三嵌段共聚物具有良好的温敏性和pH敏感性，在温度或pH诱导下可形成核壳胶束和凝胶．载药凝胶对药物的累积释放率随温度和pH的降低而升高．

英文摘要：

Novel ABA triblock copolymers P（DEAEMA-co-MEO2MA-co-HMAM）-b-PEG-b-P（DEAEMA-co-MEO2MA- co-HMAM） with different polymerization degrees which were more hydrophilic were synthesized by ATRP （atom transfer radical polymerization）. The composition and structure of the copolymer were characterized by 1H NMR, FT-IR, and gel permeation chromatograph （GPC）. The temperature- and pH-sensitivity and micellization of the ABA triblock copolymer have been studied using transmittance, surface tension, fluorescence spectra, dynamic light scattering （DLS） and transmission electron microscopy （TEM） measurements. The effects of temperature and pH on the gelation of the copolymer were studied through the gel state and the process of sol-gel transitions of copolymer induced by temperature at different pHs. The drug release of a drug-loaded gel which informed by the copolymer was tested respectively at different temperatures and pHs in buffer solutions. It was found that the copolymer had a good temperature- and pH-sensitivity, and the copolymer chains can form stable core-shell structure micelles through temperature and pH inducing. The different strength of gel can be induced by pH. In addition, the drug release of the drug-loaded gel was increased with the decrease of temperature and pH values.