基于含苯硼酸聚合物的双响应性胶束

分别合成了苯硼酸修饰的嵌段聚合物聚乙二醇-b-聚(天冬氨酸-co-天冬酰氨基苯硼酸)[PEG-b-P(Asp-co-AspPBA)]和含有二硫键及多元二醇的小分子3,3'-二硫代二[1,2(S)-丙二醇](DTBPD). 以DTBPD为小分子交联剂, 通过二醇单元与苯硼酸之间的共价酯化作用, 诱导PEG-b-P(Asp-co-AspPBA)自组装形成以苯硼酸环酯为核、 PEG为壳的交联胶束. 利用核磁共振氢谱和激光光散射对胶束的结构进行了表征, 并分别测定了该胶束在葡萄糖和氧化-还原试剂二硫苏糖醇(DTT)刺激下的响应行为. 结果表明, DTBPD可与聚合物链上的苯硼酸形成苯硼酸环酯, 通过交联作用诱导聚合物形成胶束. 交联度不同时, 胶束对于外界刺激(葡萄糖和DTT的响应行为也不同: 随着DTT和葡萄糖浓度的增加, 交联度高的胶束只发生响应性溶胀, 交联度低的胶束则先溶胀, 之后溶胀程度较大的部分胶束则发生解体, 导致胶束的平均粒径减小.

Dual-responsive Micelles Based on Boronicacid-modified Polymer†

Phenylboronic acid modified polymer poly(ethylene glycol)-b-poly(aspartic acid-co-aspartamidophenylboronic acid)[PEG-b-P(Asp-co-AspPBA)] as well as a cross-linker 3,3'-dithiobis[1,2(S)-propanediol](DTBPD) which contained disulfide bond and dual-diol groups was successfully synthesized. PEG-b-P(Asp-co-AspPBA) could be mildly cross-linked by DTBPD based on the reaction of PBA and the dual-diol groups, leading to the formation of a novel dual-responsive micelle with boronic ester core and PEG shell. The structure, morphology, and the glucose/redox dual-responsive behavior of the micelles were systematically investigated by nuclear magnetic resonance(NMR) spectrum and dynamic laser light scattering(DLS). It was demonstrated that the ratio of diol to PBA(D∶B) had influence on the dual-responsive behavior of the micelles. At higher ratio of D∶B, only responsive swelling of micelles was observed. While for the micelles with lower ratio of D∶B, larger degree of swelling happened and the micelles gradually dissociated under higher concentrations of glucose ordithiothreitol(DTT). This kind of dual-responsive micelles may find application in drug delivery in the future.