Abstract Methotrexate (MTX) anticancer drug was successfully loaded and released in a controlled manner from polymer micelles made of a diblock copolymer of poly(monomethoxy ethylene glycol)-b-poly(ε-caprolactone) (mPEG-PCL). The empty and MTX-loaded micelles (MTX/mPEG-PCL) were characterized by electron microscopy. The drug release dependence upon pH 5.4, 6.5, and 7.4 for 30 days was proven and characterized by UV-Vis spectroscopy. The cytotoxic effect of MTX/mPEG-PCL micelles on MCF-7 breast cancer cells was evaluated through an MTT assay. The morphological analysis indicated the successful formation of micelles of 76 and 131 nm for empty and MTX-loaded micelles, respectively. An encapsulation efficiency of 70.2% and a loading capacity of 8.8% were obtained. The in vitro release of MTX showed a gradual and sustained profile over 22 days, with a clear trend to much higher release at acidic pH (80 and 90% for pH 6.7 and 5.5, respectively). The MTX/mPEG-PCL micelles showed an IC50 of MCF-7 cells at 30 µg mL−1. The results suggested that MTX/mPEG-PCL could be a promising drug delivery system for cancer treatment. Graphical abstract pH-responsive copolymer micelles for methotrexate delivery

中文翻译：

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用于在肿瘤微环境中递送甲氨蝶呤的 pH 响应聚合物胶束

摘要 甲氨蝶呤 (MTX) 抗癌药物成功地从由聚（单甲氧基乙二醇）-b-聚（ε-己内酯）（mPEG-PCL）的二嵌段共聚物制成的聚合物胶束中以受控方式加载和释放。空的和装载 MTX 的胶束 (MTX/mPEG-PCL) 通过电子显微镜进行表征。药物释放对 pH 5.4、6.5 和 7.4 的 30 天依赖性已通过紫外-可见光谱证明和表征。MTX/mPEG-PCL 胶束对 MCF-7 乳腺癌细胞的细胞毒作用通过 MTT 测定进行评估。形态学分析表明，分别成功形成了 76 和 131 nm 的空胶束和装载 MTX 的胶束。获得了70.2%的包封率和8.8%的负载能力。MTX 的体外释放表现出超过 22 天的渐进和持续特征，在酸性 pH 下释放量明显增加（pH 6.7 和 5.5 分别为 80% 和 90%）。MTX/mPEG-PCL 胶束在 30 µg mL-1 时显示出 MCF-7 细胞的 IC50。结果表明，MTX/mPEG-PCL 可能是一种很有前途的癌症治疗药物递送系统。用于甲氨蝶呤递送的图形抽象 pH 响应共聚物胶束