State Key Laboratory of Chemical Resource, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China.
J Colloid Interface Sci. 2011 Dec 1;364(1):264-71. doi: 10.1016/j.jcis.2011.08.013. Epub 2011 Aug 12.
In this study, three kinds of amphiphilic block copolymers, termed MPEG-block-PDMMA, MPEG-block-PCPMA, and MPEG-block-PMPMA, which were composed of one hydrophilic monomethoxy poly(ethylene glycol) (MPEG) block and one hydrophobic polyacrylate block bearing pendant six-member cyclic ketal groups, were synthesized by atom transfer radical polymerization (ATRP). These polymers can disperse in aqueous media to self-assemble into micellar aggregates with a spherical core-shell structure with mean diameter below 300 nm. The stimuli-responsiveness of polymeric micelles from MPEG-block-PDMMA was detected by fluorescence-probe technique at pH 3.5 and 37 °C. The effect of chemical architecture and composition of the polymers on the pH-responsive properties of polymeric micelles was also studied. A combination of pH and temperature to trigger release behavior of these polymeric micelles was discussed by comparing the encapsulated molecule release ability under various pH and temperature conditions and analyzing chemical structural changes of the polymer before and after the triggering.
在这项研究中，三种两亲性嵌段共聚物，即 MPEG-嵌段-PDMMA、MPEG-嵌段-PCPMA 和 MPEG-嵌段-PMPMA，由一个亲水性单甲氧基聚（乙二醇）（MPEG）嵌段和一个带有侧挂六元环酮基的疏水性聚丙烯酸酯嵌段组成，通过原子转移自由基聚合（ATRP）合成。这些聚合物可以在水介质中分散，自组装成平均直径低于 300nm 的具有球形核壳结构的胶束聚集体。通过荧光探针技术在 pH3.5 和 37°C 下检测了 MPEG-嵌段-PDMMA 聚合物胶束的刺激响应性。还研究了聚合物的化学结构和组成对聚合物胶束的 pH 响应性质的影响。通过比较在不同 pH 值和温度条件下包封分子的释放能力，并分析触发前后聚合物的化学结构变化，讨论了 pH 和温度联合触发这些聚合物胶束释放行为的能力。
