A novel redox-sensitvie core cross-linked micelles based on disulfide-linked PEG-polypeptide hybrid polymer were prepared and demonstrated for anticancer drug delivery, where N,N-bis(acrylate) cystamine (BAC) served as cross-linker, allyl-terminated poly(γ-benzyl-L-glutamate)
(PBLG) and polyethylene glycol (PEG) methyl ether methacrylate acted as comonomers. The molecular structure and characteristics of the cross-linked micelle and the precursor were confirmed by 1H NMR and FT-IR. The cross-linked micelles could be easily degraded into individual linear short
chains (Mn = 1800) in the presence of 20 mM glutathione (GSH) by the cleavage of the disulfide linkages from the cross-linker BAC. Doxorubicin (DOX) was selected as a model anticancer drug and encapsulated into the micelles with a decent drug loading content of 21.6 wt%.
Compared to the burst release of free DOX in first 6 hours, the in vitro release studies revealed that the micelles exhibited a sustained and high cumulative drug release in GSH (up to 86%) within 24 h, rather than the relatively low release rate of 62% in PBS (pH 7.4). Cell cytoxicity
experiments showed that the obtained micelles exhibited nontoxic, and the drug-loaded micelles exhibited high anti-cancer efficacy. All the results showed that the designed cross-linked PEG-polypeptide hybrid micelles may be a promising vehicle for anticancer drug delivery with stimuli-triggered
drug release behavior in reducing environment.
一种基于二硫键连接的PEG-多肽混合聚合物制备了一种新型的氧化还原敏感的核心交联胶束,用于抗癌药物传递。其中,N,N-双(丙烯酸酯)半胱氨酸(BAC)作为交联剂,烯丙基末端的聚(γ-苯基-L-谷氨酸)(PBLG)和聚乙二醇(PEG)甲醚丙烯酸酯作为共聚单体。通过1H NMR和FT-IR证实了交联胶束和前体的分子结构和特性。在存在20 mM谷胱甘肽(GSH)的条件下,交联胶束可以通过从交联剂BAC中切割二硫键连接而轻松降解为单个线性短链(Mn = 1800)。以多柔比星(DOX)为模型抗癌药物,并将其封装到胶束中,具有21.6 wt%的良好药物负载含量。与前6小时内的自由DOX的爆发释放相比,体外释放研究表明,在GSH中胶束表现出持续和高的累积药物释放(高达86%),而在PBS(pH 7.4)中的释放速率相对较低,仅为62%。细胞毒性实验表明,所获得的胶束具有无毒性,而药物负载的胶束具有高的抗癌功效。所有结果表明,设计的交联PEG-多肽混合胶束可能是一种有前途的抗癌药物传递载体,具有在还原环境中刺激触发的药物释放行为。