Institute of Fine Chemical and Engineering, Henan University, Kaifeng, Henan, PR China.
J Microencapsul. 2009 Nov;26(7):659-66. doi: 10.3109/02652040902968968.
Cysteine modified amphiphilic block copolymer acetate-polylactide-block-poly(ethylene glycol)-Cysteine (APLA-b-PEG-Cys) was synthesized and characterized. The polymer could self-assemble to form micelles with nano-size and regularly spherical in shape in aqueous solution. Folic acid (FA) was then used as a model drug to incorporate into APLA-b-PEG-Cys micelles. To enhance the stabilization of APLA-b-PEG-Cys micelle and control the drug release, the shell of APLA-b-PEG-Cys micelle was cross-linked by the in situ polycondensation of amino acid moieties on its surface. The effects of shell-cross-linking on the micelle physical chemistry properties were investigated in detail. It was found that, after cross-linking, the CMC of the APLA-b-PEG-Cys micelle was decreased, indicating that the shell-cross-linked micelle is more stable as compared to the uncross-linked one. In addition, the shell-cross-linking also changed the surface potential, micelle size and model drug (FA) release behaviour, but it did not significantly affect the micelle morphology and drug encapsulation efficiency of APLA-b-PEG-Cys micelles.
半胱氨酸修饰的两亲嵌段共聚物醋酸酯-聚乳酸嵌段-聚乙二醇-半胱氨酸（APLA-b-PEG-Cys）被合成并进行了表征。该聚合物可以在水溶液中自组装形成纳米级、规则球形的胶束。然后，叶酸（FA）被用作模型药物来包裹入 APLA-b-PEG-Cys 胶束中。为了增强 APLA-b-PEG-Cys 胶束的稳定性并控制药物释放，APLA-b-PEG-Cys 胶束的壳通过其表面上氨基酸部分的原位缩聚进行交联。详细研究了壳交联对胶束物理化学性质的影响。结果发现，交联后，APLA-b-PEG-Cys 胶束的 CMC 降低，表明与未交联的胶束相比，壳交联的胶束更加稳定。此外，壳交联还改变了表面电位、胶束粒径和模型药物（FA）的释放行为，但对 APLA-b-PEG-Cys 胶束的胶束形态和药物包封效率没有显著影响。
