结构与组装行为可控的PLA基聚合物的制备及其对葡萄糖的响应性研究

Synthesis of Polylactide Copolymers with Controllable Structure and Self-Assembly Behavior and Their Glucose-Responsive Properties

摘要:

通过丙交酯开环聚合制备聚乳酸(PLA)的大分子链转移剂，选用4-乙烯基苯硼酸(VBA)、甲基丙烯酸二甲氨基乙酯(DMAEMA)为功能单体，通过一步法和两步法可逆加成-断裂链转移聚合(RAFT)，分别制备聚乳酸-b(聚甲基丙烯酸二甲氨基乙酯-co-聚乙烯基苯硼酸)[PLA-b-(PDMAEMA-co-PVBA)]和聚乳酸-b-聚甲基丙烯酸二甲氨基乙酯-b-聚乙烯基苯硼酸(PLA-b-PDMAEMA-b-PVBA)。对聚合物的结构和其组装纳米粒子进行测试，发现结构和组装行为可控；选择性溶剂中，PLA-b-(PDMAEMA-co-PVBA)可自组装形成胶束，PLA-b-PDMAEMA-b-PVBA仅在葡萄糖的参与下形成胶束。考察了聚合物在不同糖浓度下的刺激响应，研究结果表明：葡萄糖刺激作用下，两种聚合物胶束对葡萄糖均具有响应性，改变葡萄糖的浓度可促使纳米粒子的粒径和形貌发生变化。

Abstract:

Two types of glucose-responsive copolymers poly(lactide)-block- poly(dimethylamino-2-ethyl methacrylate)-block-polyvinyl phenylboronic acid (PLA-b-PDMAEMA-b-PVBA) and poly(lactide)-block-(poly(dimethylamino-2-ethyl methacrylate)-co-polyvinyl phenylboronic acid) [PLA-b-(PDMAEMA-co-PVBA)] were synthesized by one-step and two-step Reversible Addition-Fragmentation Chain Transfer Polymerization (RAFT), respectively, via polylactic acid (PLA) macromolecular as a chain transfer agent. These chemical structures of the copolymers had been controlled. Assembly behavior studies indicate that PLA-b-(PDMAEMA-co-PVBA) could self-assemble to form micelles in selective solvents, while PLA-b-(PDMAEMA-b-PVBA) could form micelles in glucose solvent only. Both micelles showed a good glucose-responsive property, and their particle size and morphology changed with the variation of glucose concentration.