Redox responsive biodegradable polymersomes comprising of poly(ethylene glycol)-polylactic acid-poly(ethylene glycol) [PEG-s-s-PLA-s-s-PLA-s-s-PEG] triblock copolymer with multiple disulfide linkages were developed to improve intracellular delivery and to enhance chemotherapeutic efficacy of doxorubicin in breast cancer with minimal cardiotoxicity. Folic acid and trastuzumab functionalized monodispersed polymersomes of size ∼150 nm were prepared by nanoprecipitation method while achieving enhanced doxorubicin loading of ∼32% in the polymersomes. Multiple redox responsive disulfide linkages were incorporated in the polymer in order to achieve complete disintegration of polymersomes in redox rich environment of cancer cells resulting in enhanced doxorubicin release as observed in in vitro release studies, where ∼90% doxorubicin release was achieved in pH 5.0 in the presence of 10 mM glutathione (GSH) as compared to ∼20% drug release in pH 7.4. Folic acid and trastuzumab mediated active targeting resulted in improved cellular uptake and enhanced apoptosis in in vitro studies in breast cancer cell lines. In vivo studies in Ehrlich ascites tumor bearing Swiss albino mice showed enhanced antitumor efficacy and minimal cardiotoxicity of polymersomes with ∼90% tumor regression as compared to ∼38% tumor regression observed with free doxorubicin. The results highlight therapeutic potential of the polymersomes as doxorubicin delivery nanocarrier in breast cancer therapy with its superior antitumor efficacy and minimal cardiotoxicity.
为了改善细胞内给药,提高
多柔比星在乳腺癌中的化疗效果,同时将心脏毒性降至最低,研究人员开发了具有氧化还原反应的
生物可降解聚合体,该聚合体由具有多个二
硫键的聚
乙二醇-聚
乳酸-聚
乙二醇[P
EG-s-s-P
LA-s-s-P
LA-s-s-P
EG]三嵌段共聚物组成。通过纳米沉淀法制备了叶酸和曲妥珠单抗功能化的单分散聚合体,其大小为 150 纳米,同时提高了聚合体中
多柔比星的负载量,使其达到 32%。聚合物中加入了多种氧化还原反应二
硫键,以便在富含氧化还原的癌细胞环境中实现聚合体的完全分解,从而提高
多柔比星的释放,体外释放研究观察到,在 pH 值为 5.0 且存在 10 mM
谷胱甘肽(GSH)的条件下,
多柔比星的释放率为 90%,而在 pH 值为 7.4 的条件下,药物释放率为 20%。在乳腺癌
细胞系的体外研究中,叶酸和曲妥珠单抗介导的主动靶向作用改善了细胞摄取,增强了细胞凋亡。对罹患艾氏腹
水瘤的瑞士白化小鼠进行的体内研究表明,聚合体的抗肿瘤疗效增强,心脏毒性最小,肿瘤消退率达 90%,而游离
多柔比星的肿瘤消退率仅为 38%。这些结果凸显了聚合体作为
多柔比星递送纳米载体在乳腺癌治疗中的治疗潜力,因为它具有卓越的抗肿瘤疗效和最小的心脏毒性。