酸响应性天然多糖键合药的合成及其在恶性肿瘤化疗中的应用

发布时间：2018-05-02 21:12

本文选题：pH响应 + 天然多糖键合药　；参考：《东北师范大学》2016年博士论文

【摘要】：随着环境污染和食品安全等问题的日趋恶化,恶性肿瘤已成为威胁人类健康生命的疾病,其发病率和死亡率呈逐年上升的趋势。目前,化疗仍是肿瘤治疗的最主要手段,但临床经常使用的小分子抗肿瘤药物水溶性差,体内循环周期短,代谢快,易产生多药耐药性,并且对肿瘤组织缺少靶向性。为了解决小分子药物存在的诸多问题,通过物理包埋或化学键合的方式将小分子药物与高分子结合而成的高分子纳米药物引起了广泛的关注。本论文中,以具有良好生物相容性的天然多糖为载体骨架,采用化学键合的方式将小分子抗肿瘤药物与载体材料结合,制备了一系列pH响应的天然多糖键合药,考察了药物键合率对药物传输的影响,并进一步研究了被动和主动靶向、及主动靶向双药联用对抗肿瘤效果的影响。主要研究内容如下:(1)pH响应的羟乙基淀粉-阿霉素键合药(HES=DOX)体系选用羟乙基淀粉为基本骨架,利用氧化的羟乙基淀粉的醛基与阿霉素的氨基通过高效的席夫碱反应合成酸敏感的HES=DOX,通过改变阿霉素投料摩尔比制备三种不同药物键合率的阿霉素键合药。所合成的三种天然多糖键合药在水介质中均可自组装形成胶束,通过透射电镜(TEM)和动态光散射(DLS)对其形貌和粒径进行了考察。随后对三种天然多糖键合药的体外释放、细胞毒性、细胞内吞、体内肿瘤抑制情况进行研究。HES=DOX通过增强渗透与滞留效应(EPR被动靶向效应)可以到达肿瘤组织,并被细胞内吞,在细胞内低pH值的环境下快速裂解释放出阿霉素,达到肿瘤抑制的目的。结果表明,三种天然多糖键合药均可有效的降低小分子药物的毒副作用,延长体内循环时间,抑制肿瘤生长,且随着药物键合率的升高,肿瘤抑制能力增强。(2)主动靶向的酸敏感的羟乙基淀粉-阿霉素键合药(HES=DOX/cRGD)基于前面的研究,在天然多糖键合药中引入主动靶向分子,使天然多糖键合药通过主动靶向作用到达肿瘤组织,进一步增加天然多糖键合药在肿瘤组织的聚集,并通过与靶向受体结合进入肿瘤细胞,在肿瘤细胞内低pH情况下触发释放药物。将带有氨基的cRGD靶向分子和阿霉素分别通过席夫碱键连接到醛基化的羟乙基淀粉上。在2小时的细胞内吞和胞内药物释放实验中,αvβ3整合素过表达的A375细胞对HES=DOX/cRGD胶束具有更高的摄取。在体内肿瘤抑制生长实验中,靶向天然多糖键合药具有更高效的治疗效果,并且通过免疫组化分析进一步确定靶向天然多糖键合药可以导致更多的肿瘤细胞凋亡,并且降低了对其他器官的毒副作用。(3)自靶向的酸敏感的葡聚糖-阿霉素键合药(Dex-g-DOX)为了解决天然多糖键合药胶束的药物突释和提高水溶性,以具有更好水溶性和易于功能化的天然多糖-葡聚糖为基础骨架,制备酸敏感的葡聚糖基键合药。葡聚糖和顺式乌头酸酐修饰的DOX通过简单高效的缩合反应制备酸敏感的天然多糖键合药。值得注意的是,这两个分子之间是通过酸裂解的酰胺键连接的。Dex经体内循环后选择性聚集在肝脏部位,Dex-g-DOX实现在肝脏肿瘤部位的高强度聚集。由于Dex和DOX之间是通过酸响应的酰胺键进行连接的,所以Dex-g-DOX可以在酸性的内涵体和溶酶体内选择释放DOX,以增强DOX对肿瘤细胞的抑制能力。(4)具有主动靶向的酸敏感的葡聚糖-阿霉素/硼替佐米协同键合药(Dex-g-DOX/BTZ/cRGD)为了减少或消除单一药物所存在的耐药性,提高肿瘤抑制能力,将阿霉素(抑制核酸合成)和硼替佐米(抑制核因子-κB(NF-κB))分别通过酸敏感的席夫碱键和硼酯键与葡聚糖连接,并将能与αvβ3整合素受体相结合的靶向分子cRGD,也通过酸敏感的席夫碱键键合到葡聚糖上。所合成的靶向天然多糖键合药胶束,通过靶向受体介导进入肿瘤细胞,并在肿瘤细胞低pH的环境下释放出抗肿瘤药物,实现了药物的协同治疗。在本论文的研究中,得到了具有较好肿瘤治疗效果的pH响应的天然多糖键合药。期望这种合成步骤简单,治疗效果显著的天然多糖键合药体系对高分子键合药的临床研究提供基础实验依据,为新型纳米药物的研发奠定基础。
[Abstract]:With the worsening of environmental pollution and food safety, malignant tumor has become a disease that threatens human health. Its incidence and mortality are increasing year by year. At present, chemotherapy is still the most important means of cancer treatment, but the small molecular antitumor drugs often used in clinical use are poor in water solubility and short cycle cycle in the body. In order to solve the problems of small molecular drugs, a wide range of polymer nanoscale drugs are produced by combining physical encapsulation or chemical bonding with small molecular drugs and polymers. In this paper, a good biocompatibility is made in this paper. Natural polysaccharide was used as the carrier skeleton. A series of natural polysaccharide bonds with pH response were prepared by combining chemical bonding with the carrier materials. The effects of the drug bonding rate on the drug delivery were investigated, and the effects of passive and active targeting and the active target targeted double drugs were further studied. The main research contents are as follows: (1) hydroxyethyl starch in the hydroxyethyl starch and adriamycin bond (HES=DOX) system of pH responds to hydroxyethyl starch as the basic skeleton. The acid sensitive HES= DOX is synthesized by the reaction of the aldehyde group of oxidized hydroxyethyl starch and amido of adriamycin by high efficient Schiff base. Three different kinds of adriamycin feed ratio are prepared by changing the ratio of the dosage of adriamycin. The drug bond rate of adriamycin bond. The three kinds of natural polysaccharides can be assembled into a micelle in water medium. The morphology and particle size of the three compounds are investigated by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The release, cytotoxicity, endocytosis, and tumor inhibition of the three natural polysaccharide bonds are followed. .HES=DOX can reach tumor tissue by enhancing osmosis and retention effect (EPR passive targeting effect) and endocytosis by cells and release adriamycin in a low pH environment. The results show that the three natural polysaccharide bonds can effectively reduce the toxicity of small molecular drugs. Side effects, prolong the circulation time of the body, inhibit the growth of the tumor, and increase the tumor inhibition ability with the increase of the drug bonding rate. (2) the active target acid sensitive hydroxyethyl amyloid adriamycin bond (HES=DOX/cRGD) is based on the previous study, and the active target molecule is introduced into the natural polysaccharide bond, so that the natural polysaccharide bond is passed through the main drug. To reach the tumor tissue by moving target, further increase the accumulation of natural polysaccharide bond in tumor tissue, and enter into tumor cells by combining with the target receptor and trigger release drug under the low pH condition in the tumor cells. The cRGD target molecules with amino group and adriamycin are connected to the aldehyde based hydroxyethyl Lake respectively by the Schiff base bond. In 2 hours of endocytosis and intracellular drug release experiments, alpha v beta 3 integrin overexpressed A375 cells have higher uptake of HES=DOX/cRGD micelles. In vivo tumor inhibition growth experiments, targeted natural polysaccharide bonds have a more effective therapeutic effect, and the target nature is further determined by immunohistochemical analysis. Sugar bonds can cause more apoptosis of tumor cells and reduce the toxic and side effects to other organs. (3) the self targeting acid sensitive dextran doxorubicin bond (Dex-g-DOX) is used to solve the drug release and water solubility of natural polysaccharide bond micelles, with a better water-soluble and functional natural polysaccharide Portuguese. An acid sensitive glucan based bond is prepared based on chitosan. Dextran and CIS Aconitum modified DOX can be used to prepare acid sensitive natural polysaccharide bonds by a simple and efficient condensation reaction. It is worth noting that the two molecules are selectively aggregated in the liver through the acid cleavage of the amide linked.Dex through the body. In the dirty site, Dex-g-DOX is highly concentrated in the tumor site of the liver. Since Dex and DOX are linked by acid responsive amide bonds, Dex-g-DOX can release DOX in acid endosomes and enzymes to enhance the inhibitory ability of DOX to tumor cells. (4) acid sensitive dextran with active target. Mycophenin / bortezomib synergistic bond (Dex-g-DOX/BTZ/cRGD), in order to reduce or eliminate the drug resistance of a single drug, improves the tumor suppressive ability. Adriamycin (inhibition of nucleic acid synthesis) and bortezomib (inhibition of nuclear factor kappa B (NF- kappa B)) are connected by acid sensitive Schiff base and borate bonds to glucan respectively, and will be able to integrate with alpha v beta 3. The target molecule cRGD, combined with a peptide receptor, is also linked to dextran by acid sensitive Schiff base bond. The targeted natural polysaccharide binding micelles are introduced into tumor cells through targeted receptors, and antitumor drugs are released under the low pH environment of the tumor cells to achieve the synergistic treatment of drugs. In this paper, the study was carried out in this paper. The natural polysaccharide bond of pH response with better tumor treatment effect is obtained. It is expected that this synthetic procedure is simple. The natural polysaccharide bond system with significant therapeutic effect provides the basic experimental basis for the clinical study of polymer bond, and lays the foundation for the research and development of new nanoscale drugs.

【学位授予单位】：东北师范大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R730.5;TQ464.1

【参考文献】