Synthesis of a Novel Polymeric Material Folate-Poly(2-ethyl-2-oxazoline)-Distearoyl Phosphatidyl Ethanolamine Tri-Block Polymer for Dual Receptor and pH-Sensitive Targeting Liposome
作者:GuiMin Xia、ZhiJiao An、Yang Wang、Chen Zhao、Mei Li、ZiChen Li、Jie Ma
DOI:10.1248/cpb.c12-00951
日期:——
The in vivo distribution of antitumor drugs is usually lack of selectivity, and thus, leading to a low efficacy of chemotherapy on cancers and high toxicity to normal cells. Receptor-mediated targeting liposome with pH-sensitivity as a dual drug delivery system is one of the efficient approaches to overcome the disadvantages. The study was to synthesize a novel smart polymeric material (folate-poly(2-ethyl-2-oxazoline)-distearoyl phosphatidyl ethanolamine, F-PEOz-DSPE), which can combine with the folate-receptor (FR) over-expressed on cancer cells and respond to pH changes in endosome–lysosome system in cancer cells to rapidly release drug simultaneously. The F-PEOz-DSPE was synthesized by the method of asymmetric synthesis of organic polymer and characterized by IR, 1H-NMR, electrospray ionization (ESI)-MS and gel permeation chromatography (GPC). To investigate the properties of targeting and pH-sensitivity of F-PEOz-DSPE, blank liposomes, blank fluorescently labeled liposomes and doxorubicin (DOX)-loaded liposomes containing F-PEOz-DSPE or PEOz-DSPE or DSPE were prepared. The cytotoxicity, cellular uptake and drug cumulative release in vitro were investigated. Blank liposomes modified with PEOz block had little cytotoxicity in vitro. The liposomes containing F-PEOz-DSPE showed a higher affinity to human ovarian cancer cell SKOV3, a FR+ cancer cells, than those with PEOz-DSPE. A higher drug cumulative release from DOX-loaded liposomes containing F-PEOz-DSPE or PEOz-DSPE in vitro was found in phosphate buffered saline at pH 5.0 medium than at pH 7.4. These results indicate that F-PEOz-DSPE exhibits selective targeting, pH-sensitivity and little cytotoxicity, and may be a promising polymeric material for dual receptor and pH-sensitive targeting liposome.
抗肿瘤药物在体内的分布通常缺乏选择性,因此导致化疗对癌症的疗效低,而对正常细胞的毒性高。具有 pH 敏感性的受体介导靶向脂质体作为双重给药系统是克服上述缺点的有效方法之一。本研究旨在合成一种新型智能高分子材料(叶酸-聚(2-乙基-2-噁唑啉)-双硬脂酰磷脂酰乙醇胺,F-PEOz-DSPE),它能与癌细胞上过度表达的叶酸受体(FR)结合,并能响应癌细胞内膜-溶酶体系统的pH变化,同时快速释放药物。采用有机聚合物不对称合成法合成了 F-PEOz-DSPE,并通过红外光谱、1H-NMR、电喷雾质谱(ESI)和凝胶渗透色谱(GPC)对其进行了表征。为了研究 F-PEOz-DSPE 的靶向性和 pH 敏感性,制备了空白脂质体、空白荧光标记脂质体和含有 F-PEOz-DSPE 或 PEOz-DSPE 或 DSPE 的多柔比星(DOX)负载脂质体。研究了体外细胞毒性、细胞吸收和药物累积释放情况。用 PEOz 嵌段修饰的空白脂质体在体外几乎没有细胞毒性。与含有 PEOz-DSPE 的脂质体相比,含有 F-PEOz-DSPE 的脂质体对人卵巢癌细胞 SKOV3(一种 FR+ 癌细胞)的亲和力更高。在体外实验中,含有 F-PEOz-DSPE 或 PEOz-DSPE 的 DOX 脂质体在 pH 值为 5.0 的磷酸盐缓冲盐水介质中的药物累积释放量高于 pH 值为 7.4 的介质。这些结果表明,F-PEOz-DSPE 具有选择性靶向、pH 敏感性和较小的细胞毒性,可能是一种很有前途的双受体和 pH 敏感性靶向脂质体聚合物材料。