基于物理包裹作用制备肿瘤穿透肽修饰PGG-PTX递药系统的研究

发布时间：2018-05-16 18:02

本文选题：物理包裹 + 胶质母细胞瘤　；参考：《华东师范大学》2017年硕士论文

【摘要】：近几年我国的肿瘤新生发病率持续上升,我国癌症新发癌症病例占世界的1/4,在众多癌症类型中,胶质母细胞瘤具有发病率高,难治愈,易复发,患者生存周期短,生活质量差等特点。面对如此严峻的形势,科研工作者需要制备并研发出新型抗肿瘤靶向纳米递药系统用于癌症的治疗。人们通常用化学连接的方法将多肽等靶向配体修饰在不同纳米材料表面,形成抗肿瘤靶向纳米递药系统。但往往涉及到化学反应,就要考虑到反应条件,步骤是否繁琐,以及所用基团是否可用,产物纯度,反应过程越多产量越低等问题。我们改变这种常用的靶向修饰方式,减少反应步骤,将纳米递药系统的制备模块化,将具有不同功能的模块化元件通过物理相互作用进行组装,避开化学合成的繁琐,使得纳米递药系统的制备更加便捷可控。首先制备功能性靶向元件,再通过物理包裹作用制备肿瘤穿透肽修饰的PGG-PTX递药系统。该系统包含RGERPPR多肽修饰的靶向元件,高分子聚合物及抗肿瘤药物,此中靶向元件为二硬脂酰磷脂酰乙醇胺-聚乙二醇3400-RGERPPR(DSPE-PEG3400-RGERPPR);高分子聚合物(PGG)为聚谷氨酸骨架及骨架上的谷氨酸支链;抗肿瘤药物为紫杉醇(PTX);聚谷氨酸高分子骨架和谷氨酸支链通过肽键连接,在谷氨酸支链末端与抗肿瘤药物PTX通过酯键键合,形成PGG-PTX。然后PTX与靶向元件中的DSPE通过疏水相互作用,使靶向元件疏水端DSPE包裹进入PGG-PTX中,通过物理包裹作用形成聚合物-药物纳米递药系统,用于肿瘤靶向递药。通过动态蒸发光散射仪、高效液相色谱仪、流式细胞仪、透射电镜等仪器和方法对RGE-PEG-DSPE/PGG-PTX纳米递药系统进行了一系列表征。试验结果显示:粒径在100 nm左右,呈球形,分散性良好;在PBS中长期保存稳定性良好;药物释放缓慢;细胞摄取试验中通过定性定量试验可以看出肿瘤细胞和血管内皮细胞均对该递药系统的摄取明显增多,该递药系统对胶质母细胞瘤的靶向能力较好;体外抗神经胶质瘤活性评价中该递药系统显著增强了胶束纳米药物对神经胶质瘤的体外生长抑制作用;通过静脉注射给药,利用肿瘤EPR效应和RGERPPR介导作用将其靶向至肿瘤部位,此递药系统可用作肿瘤治疗药物的靶向递送,且在治疗脑胶质瘤上获得了良好的疗效,延长了 BALB/C脑胶质瘤裸鼠的中位生存期,改善了荷瘤裸鼠的生存状况。此递药系统可在RGERPPR的介导作用下用于胶质母细胞瘤的靶向治疗。为靶向纳米药物的构建提供了新的思路和方法,同时为胶质母细胞瘤的靶向治疗提供实验基础。因此本研究拥有重要的临床现实意义和市场应用价值,拥有良好的应用前景。
[Abstract]:In recent years, the incidence of neoplasms has been rising in China, and new cancer cases in China account for one fourth of the world's total cancer cases. Among the many cancer types, glioblastoma has a high incidence rate, is difficult to cure, easy to recur, and has a short life cycle. Poor quality of life and other characteristics. Faced with such a severe situation, researchers need to prepare and develop a novel anti-tumor targeted nano-delivery system for cancer treatment. Peptides and other targeted ligands are usually modified on the surface of different nanomaterials by chemical binding to form anti-tumor targeted drug delivery system. However, chemical reactions are often involved, such as the reaction conditions, whether the steps are tedious, whether the groups used are available, the purity of the product, the lower the yield of the reaction process, and so on. We change this common targeting modification, reduce the reaction steps, modularize the preparation of nanopharmaceutical systems, assemble modular components with different functions through physical interactions, and avoid the red tape of chemical synthesis. The preparation of nano-delivery system is more convenient and controllable. First, functional target elements were prepared, and then the tumor penetrating peptide modified PGG-PTX delivery system was prepared by physical encapsulation. The system consists of RGERPPR polypeptide modified target elements, polymer polymers and antitumor drugs, in which the target elements are DSPE-PEG3400-RGERPPRN, which are DSPE-PEG3400-RGERPPRA, and the polyglutamic acid backbone and its branched chains on the framework of poly (glutamic acid), the target elements of the system are DSPE-PEG3400-RGERPPRA. The antitumor drug was paclitaxel, the polyglutamic acid polymer skeleton and the glutamic acid branched chain were connected by peptide bond, and the end of the glutamic acid branched chain was bonded with the antitumor drug PTX through ester bond to form PGG-PTX. Then the PTX and the DSPE in the target element interact with each other through hydrophobic interaction, and the hydrophobic end DSPE of the target element is encapsulated into the PGG-PTX, and the polymer-drug delivery system is formed by physical encapsulation, which can be used for tumor targeting delivery. The RGE-PEG-DSPE/PGG-PTX nano-drug delivery system was characterized by means of dynamic evaporative light scattering, high performance liquid chromatography, flow cytometry and transmission electron microscope. The results showed that the particle size was about 100nm, spherical and dispersive, the stability of PBS was good, the drug release was slow. In the cell uptake test, it can be seen that both tumor cells and vascular endothelial cells have significantly increased uptake of the drug delivery system, and the drug delivery system has a better targeting ability to glioblastoma. In the evaluation of anti-glioma activity in vitro, the drug delivery system significantly enhanced the inhibitory effect of micellar nanopharmaceuticals on the growth of gliomas in vitro, which was targeted to the tumor site by intravenous administration of EPR and RGERPPR mediated action. The delivery system can be used as the target delivery of tumor therapy drugs, and it has a good effect on the treatment of brain glioma, prolongs the median survival time of BALB/C glioma nude mice, and improves the survival condition of nude mice bearing tumor. The drug delivery system can be used in targeted treatment of glioblastoma mediated by RGERPPR. It provides new ideas and methods for the construction of targeted nanopharmaceuticals and provides experimental basis for targeted treatment of glioblastoma. Therefore, this study has important clinical significance and market application value, and has a good application prospects.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R943

【参考文献】