Abstract A ketal core cross-linked (CCL) micelle system of block copolymers of poly(oligo(ethylene glycol) methyl ether methacrylate)-b-poly(styrene-alt-maleic anhydride)-b-poly(styrene) (POEGMA-b-PSMA-b-PS) was prepared by the combination of the reversible addition-fragmentation chain transfer (RAFT) polymerization and amidation process. Doxorubincin (DOX), a model anticancer drug, was loaded into block copolymer micelles with POEGMA segment as hydrophilic corona and PSMA-b-PS block as hydrophobic core. Then core cross-linking was carried out by amidation reaction between maleic anhydride moiety and difunctional amino cross-linker bearing an acid cleavable bond (ketal). The ketal CCL micelles illustrated good stability under physiological condition but disassociated rapidly under acidic pH conditions. TEM images presented spherical shape of CCL micelles with average hydrodynamic diameter at around 45 nm. The DOX release experiments demonstrated a rapid DOX release at pH 5.0 compared to pH 7.4.

中文翻译：

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缩酮核交联胶束用于 pH 触发多柔比星的释放

摘要 聚（低聚（乙二醇）甲基醚甲基丙烯酸酯）-b-聚（苯乙烯-alt-马来酸酐）-b-聚（苯乙烯）（POEGMA-b）嵌段共聚物的缩酮核交联（CCL）胶束体系-PSMA-b-PS) 是通过可逆加成-断裂链转移 (RAFT) 聚合和酰胺化过程的组合制备的。多柔比星（DOX）是一种模型抗癌药物，被加载到具有 POEGMA 段作为亲水冠和 PSMA-b-PS 嵌段作为疏水核的嵌段共聚物胶束中。然后通过马来酸酐部分和带有酸可裂解键（缩酮）的双官能氨基交联剂之间的酰胺化反应进行核心交联。缩酮 CCL 胶束在生理条件下表现出良好的稳定性，但在酸性 pH 条件下迅速解离。TEM 图像显示了 CCL 胶束的球形形状，平均流体动力学直径约为 45 nm。DOX 释放实验表明，与 pH 7.4 相比，在 pH 5.0 下 DOX 释放更快。