超支化聚乙烯亚胺-聚天冬氨酸苄酯共聚物的制备及性能

以超支化聚合物聚乙烯亚胺为引发剂, 天冬氨酸苄酯-NCA为单体, 利用热开环聚合法合成了超支化聚乙烯亚胺-聚天冬氨酸苄酯共聚物(PEI-PBLA). 用核磁共振波谱对PEI-PBLA的化学结构进行了表征. 研究了PEI-PBLA在水溶液及有机溶液中的自组装行为. 以芘为荧光探针测定了共聚物在水中形成胶束的临界胶束浓度. 以甲基橙为客体分子, 研究了共聚物胶束的包覆能力, 结果表明, 共聚物对客体分子的吸附与溶液的pH值有关. 研究了共聚物与质粒DNA的复合发现, PEI-PBLA能够很好地与质粒DNA复合, 并且可以避免DNA酶的降解, 对其起到一定的保护作用. 此聚合物在药物传输、可控释放及基因载体等方面都有着潜在的应用价值.

Synthesis,Self-assembly and Gene Transfection Hyperbranched Polyethylenimine-poly(β-benzyl-L-aspartate) Copolymer

A novel amphiphilic and biodegradable copolymer of hyperbranched polyethylenimine-poly(β-benzyl-L-aspartate)(PEI-PBLA) was synthesized by ring opening polymerization of the N-carboxyanhydride of β-benzyl-L-aspartate(BLA-NCA) with hyperbranched polyethylenimine(PEI) as initiator and characterized by ¹H NMR. PEI-PBLA copolymers could form micelles in both organic solvent and water. The micelle formation of PEI-PBLA in CH₂Cl₂ was displayed by extraction of methyl orange indicator from aqueous solutions. As for PEI-PBLA micelle in water, the critical micelle concentration(cmc) was determined by fluorescence probe method and corresponding morphology was observed by TEM. Meanwhile, the complexation of PEI-PBLA with DNA was explored by gel retardation. The studies imply that PEI-PBLA has great potential in many applications, such as drug delivery, gene transfection and so on.