Micellization and sol-gel transition of novel thermo- and pH-responsive ABC triblock copolymer synthesized by RAFT
Micellization and sol-gel transition of novel thermo- and pH-responsive ABC triblock copolymer synthesized by RAFT
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RAFT合成的新型热响应性和pH响应性ABC三嵌段共聚物的胶束化和溶胶-凝胶转变
DOI：
10.1007/s10965-018-1658-4
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发表时间：
2018-11-23
影响因子：
2.8
通讯作者：
Shi, Xiaoyu
中科院分区：
文献类型：
--
作者：
Liu, Shouxin;Tian, Lei;Shi, Xiaoyu
通过可逆加成断裂链转移聚合合成了一种明确的热响应性和pH响应性ABC型三嵌段共聚物单甲氧基聚(乙二醇)-b-聚(2-(2-甲氧基乙氧基)甲基丙烯酸乙酯-共聚-N-羟甲基丙烯酰胺)-b-聚(2-(二乙氨基)甲基丙烯酸乙酯)，mPEG-b-P(MEO2MA-co-HMAM)-b-PDEAEMA，通过可逆加成断裂链转移聚合合成（木筏）。 ABC型三嵌段共聚物具有热响应性和pH响应性，分别对应于P(MEO2MA-co-HMAM)的热敏特性和PDEAEMA片段的pH响应特性。通过紫外透射率测量、动态光散射 (DLS)、透射电子显微镜 (TEM) 研究了共聚物水溶液的热响应和 pH 响应特性。结果表明，三嵌段共聚物中N-羟甲基丙烯酰胺（HMAM）含量影响三嵌段共聚物水溶液的下临界溶解温度（LCST）。该共聚物在室温碱性溶液中自组装成以热响应性P(MEO2MA-co-HMAM)嵌段和亲水性PEG嵌段为壳、疏水性PDEAEMA嵌段为核的核壳胶束。而在酸性介质中，当温度高于三嵌段共聚物水溶液的下临界溶液温度（LCST）时，共聚物自组装成具有混合亲水性PEG和pH响应性PDEAEMA冠的P(MEO2MA-co-HMAM)核胶束。通过小瓶倒转测试测定的三嵌段共聚物的溶胶-凝胶转变温度(Tsol-gel)进一步表明它取决于三嵌段共聚物的浓度和溶液pH值。负载牛血清白蛋白（BSA）的共聚物水凝胶用于缓释研究。结果表明，水凝胶是控制蛋白质药物递送的有前途的候选者。
A well-defined thermo- and pH-responsive ABC-type triblock copolymer monomethoxy poly(ethylene glycol)-b-poly(2-(2-methoxyethoxy) ethyl methacrylate-co-N-hydroxymethyl acrylamide)-b-poly(2-(diethylamino) ethyl methacrylate), mPEG-b-P(MEO2MA-co-HMAM)-b-PDEAEMA, was synthesized by reversible addition-fragmentation chain transfer polymerization (RAFT). The ABC-type triblock copolymer was endowed thermo- and pH-responsive, corresponding to the thermosensitive properties of P(MEO2MA-co-HMAM) and pH-responsive properties PDEAEMA segments, respectively. The thermo- and pH-responsive properties of copolymer aqueous solutions were studied by UV transmittance measurements, dynamic light scattering (DLS), transmission electron microscopy (TEM). The results showed that the N-hydroxymethyl acrylamide (HMAM) content in triblock copolymer affected the lower critical solution temperature (LCST) of the triblock copolymer aqueous solution. The copolymer self-assembled into core-shell micelles, with the thermoresponsive P(MEO2MA-co-HMAM) block and the hydrophilic PEG block as the shell, the hydrophobic PDEAEMA block as the core, in alkaline solution at room temperature. While in acidic media, when the temperature above the lower critical solution temperature (LCST) of the triblock copolymer aqueous solution, the copolymer self-assembled into P(MEO2MA-co-HMAM)-core micelles with mixed hydrophilic PEG and pH-responsive PDEAEMA coronas. Sol-gel transition temperature (Tsol-gel) for the triblock copolymer determined by vial inversion test further indicated that it is dependent on the concentration of the triblock copolymers and solution pH. Copolymer hydrogel loaded with bovine serum albumin (BSA) were used for the sustained release study. The results indicated that the hydrogel was a promising candidate for controlling protein drug delivery.