School of Chemistry and Chemical Engineering, South China University of Technology , Wusan Street, Guangzhou 510640, P. R. China.
J Phys Chem B. 2013 Oct 31;117(43):13688-97. doi: 10.1021/jp407529u. Epub 2013 Oct 17.
Dissipative particle dynamics (DPD) simulation was applied to investigate the microstructures of the micelles self-assembled from pH-sensitive four-arm star triblock poly(ε-caprolactone)-b-poly(2-(diethylamino)ethyl methacrylate)-b-poly(poly(ethylene glycol) methyl ether methacrylate) (4AS-PCL-b-PDEAEMA-b-PPEGMA). In the optimized system, the micelles have a core-mesosphere-shell three-layer structure. The drug-loading process and its distribution at different formulations in the micelles were studied. The results show that DOX molecules distributed in the core and the interface between the core and the mesosphere, suggesting the potential encapsulation capacity of DOX molecules. More drugs were loaded in the micelles with the increase in DOX, and the size of micelles became larger. However, some openings start to generate on the PEG shell when the DOX reaches a certain concentration. By changing the pH values of the system, different morphologies of the micelles were acquired after the pH-sensitive blocks PDEAEMA were protonated, the mechanism of which was also analyzed through correlating functions. The results indicated that the sudden increase in solubility parameter of the pH-sensitive blocks and the swelling of the micelles were the key factors on the change of morphologies. Furthermore, with the decrease in pH value, the number and size of the cracks on the surface of the micelles were larger, which may have a direct effect on the drug release. In conclusion, 4AS-PCL-b-PDEAEMA-b-PPEGMA has great promising applications in delivering hydrophobic anticancer drugs for improved cancer therapy.
耗散粒子动力学（DPD）模拟被应用于研究由 pH 敏感的四臂星型嵌段共聚物聚（ε-己内酯）-b-聚（2-（二乙氨基）乙基甲基丙烯酸酯）-b-聚（聚（乙二醇）甲基醚甲基丙烯酸酯）（4AS-PCL-b-PDEAEMA-b-PPEGMA）自组装形成的胶束的微观结构。在优化的系统中，胶束具有核-介孔壳三层结构。研究了载药过程及其在不同配方的胶束中的分布。结果表明，DOX 分子分布在核和核与介孔之间的界面处，表明 DOX 分子具有潜在的包封能力。随着 DOX 的增加，更多的药物被载入胶束中，胶束的尺寸也变大。然而，当 DOX 达到一定浓度时，PEG 壳上开始出现一些开口。通过改变系统的 pH 值，在 pH 敏感嵌段 PDEAEMA 质子化后获得了不同形态的胶束，通过关联函数分析了其机制。结果表明，pH 敏感嵌段溶解度参数的突然增加和胶束的溶胀是形态变化的关键因素。此外，随着 pH 值的降低，胶束表面的裂缝数量和大小更大，这可能直接影响药物释放。总之，4AS-PCL-b-PDEAEMA-b-PPEGMA 在递运疏水性抗癌药物以改善癌症治疗方面具有很大的应用前景。
