载阿霉素星型多臂PLGA-PEG嵌段共聚物纳米胶束的构建

Study on doxoru bicin-loaded star-shaped multi-arm PLGA-PEG-NH2 nanomicelles

目的 利用星型多臂端氨基聚乙丙交酯/聚乙二醇[4s-（ PLGA-PEG-NH2）]两亲性嵌段共聚物作为载体材料,构建抗肿瘤药物阿霉素纳米胶束载药体系.方法 合成聚合物4s-（ PLGA-PEG-NH2）,通过核磁共振氢谱（1H NMR）和凝胶渗透色谱（GPC）对其组成、结构及相对分子质量进行表征；采用溶剂挥发法制备阿霉素（DOX）聚合物纳米胶束,并通过透射电子显微镜（TEM）、粒径分析仪及荧光分析法对载药纳米胶束进行表征；对阿霉素载药纳米胶束在HeLa细胞中的摄取及细胞毒性进行了初步评价.结果 1H NMR与GPC测定结果表明：合成的共聚物符合设计的4s-（ PLGA-PEG-NH2）结构；能成功物理包埋DOX药物分子在水溶液中自组装成核-壳结构的纳米胶束,载药量约为7.5％,包埋率约为75.2％,Zeta电位为-17.6 mV;体外细胞实验显示：载阿霉素星型4臂聚合物纳米胶束[DOX-loaded 4s-（PLGA-PEG-NH2）micelles]比载阿霉素线性聚合物纳米胶束[DOX-loaded linear-（ PLGA-PEG-PLGA）micelles]可更有效地被HeLa细胞摄取,并对HeLa细胞的毒性更强.结论 4s-（ PLGA-PEG-NH2）阿霉素载药纳米胶束可有效提高HeLa细胞的摄取率以及对HeLa细胞的杀伤率,提示其可作为一类新型的抗肿瘤药物递送载体.

Objective To develop doxorubicine-loaded nanomicelles based on a type of novel star- shaped 4-arm PLGA-PEG-NH2 amphiphilic block eopolymers. Methods 4s-（PLGA-PEG-NH2） synthesized by 4s-PLGA and （H2N-PEG-NH2） according to N, N＇-dicyclohexylearbodiimide（DCC） condensation reaction was demonstrated by IH NMR spectroscopy and gel permeation chromatography（GPC）; DOX-loaded 4s-（PLGA-PEG- NH2） nanomieelles were self-assembled by doxorubicin（DOX） and 4s-（PLGA-PEG-NH2） via emulsion-solvent evaporation method and characterized in terms of morphology, particle size and size distribution, drug loading, encapsulation efficacy, cell uptake and cytotoxicity studies. Results 4s-（PLGA-PEG-NH2） were capable of self- assembling into ＂core-shell＂ nanomieelles structure and encapsulating DOX into their hydrophobic cores. The mean size of DOX-loaded 4s-（PLGA-PEG-NH2） was nanometer size; drug loading and encapsulation efficacy were around 7.5% and 75.2%, respectively. Mean surface charge of the mieelles was around -17.6 mV. In vitro cell uptake and eytotoxieity studies indicated that comparing to the DOX-loaded Iinear-（PLGA-PEG-PLGA） nanomicelles, DOX-loaded 4s-（PLGA-PEG-NH2） nanomieelles showed better performance in uptaking by HeLa cells and higher cytotoxicity to cancer cells. Conclusion 4s-（PLGA-PEG-NH2） amphiphilic block eopolymers can be successfully used in encapsulating DOX, self-assembling ＂core-shell＂ nanomicelles in aqueous solvent. Therefore, 4s-（PLGA-PEG-NH2） eopolymers can be considered as a promising drug carrier in effectively carrying hydrophobic drug, improving the efficacy while reducing the side effect.