School of Environmental and Chemical Engineering, Zhaoqing University, Zhaoqing, 526061, Guangdong, China.
Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, 650500, Yunnan, China.
Phys Chem Chem Phys. 2019 Jul 10;21(27):15222-15232. doi: 10.1039/c9cp02411e.
Star-shaped polymers have received significant attention and have been widely developed for prospective applications in drug delivery owing to their topological structure and unique physiochemical characteristics. The anticancer drug doxorubicin (DOX) was used as a model drug, and four/six-arm star-shaped block polymeric micelles were employed as the carriers. The dissipative particle dynamics (DPD) method was adopted to simulate the formation of micelles, the effects of the hydrophobic/hydrophilic block ratio on the micellar structure and drug-loading performance, the effect of the drug loading content on the micellar morphology, and the effect of the pH-sensitive block ratio on the drug release properties. Under neutral conditions (pH = 7.4), increasing the hydrophobic block ratio reduces the stability of the micelle structure but could improve its drug loading performance. Increasing the pH-sensitive block (DEAEMA) ratio is beneficial to the drug loading performance of the mikto-arm star-shaped polymeric micelles and is detrimental to the drug loading performance of the herto-arm star-shaped polymeric micelles. After comparing the structural changes, radial distribution function (RDF) and mean square displacement (MSD) of the polymeric micelles with different pH-sensitive block ratios under weakly acidic conditions (pH = 5.0), the drug release properties of the drug-loaded micelles were systematically analysed. The results showed that the higher the proportion of the pH-sensitive block in the polymeric micelles, the better their pH-response performance, and the looser the structure of the micelles during the release process. A too high or too low ratio of pH-sensitive blocks in the polymeric micelles was detrimental to drug release performance. This study could provide theoretical support for the structural design and development of novel functional block polymers.
星形聚合物因其拓扑结构和独特的物理化学特性而受到广泛关注，并已被广泛开发用于药物传递的潜在应用。阿霉素（DOX）被用作模型药物，四/六臂星形嵌段聚合物胶束被用作载体。采用耗散粒子动力学（DPD）方法模拟胶束的形成，研究了疏水/亲水嵌段比对胶束结构和载药性能的影响、载药含量对胶束形态的影响以及 pH 敏感嵌段比对药物释放性能的影响。在中性条件下（pH = 7.4），增加疏水嵌段比会降低胶束结构的稳定性，但可以提高其载药性能。增加 pH 敏感嵌段（DEAEMA）的比例有利于提高杂臂星形聚合物胶束的载药性能，不利于提高同臂星形聚合物胶束的载药性能。比较不同 pH 敏感嵌段比的聚合物胶束在弱酸性条件下（pH = 5.0）的结构变化、径向分布函数（RDF）和均方根位移（MSD）后，系统分析了载药胶束的药物释放性能。结果表明，聚合物胶束中 pH 敏感嵌段的比例越高，其 pH 响应性能越好，在释放过程中胶束的结构越松散。聚合物胶束中 pH 敏感嵌段的比例过高或过低都不利于药物释放性能。本研究可为新型功能嵌段聚合物的结构设计和开发提供理论支持。
