基于四氧化三铁@二氧化锰核壳结构纳米颗粒捕获与释放循环肿瘤细胞

发布时间：2018-04-01 14:04

本文选题：核壳结构四氧化三铁@二氧化锰纳米颗粒　切入点：循环肿瘤细胞　出处：《武汉大学》2017年硕士论文

【摘要】：在物理、化学和生物等致瘤因素作用下,部分组织细胞在基因水平上失去对其生长、分化的正常调控导致其生长不受机体生理调节无限增殖而破坏正常组织与器官。不仅如此,部分肿瘤细胞还会转移至其他器官形成转移灶,有研究表明,癌症患者死亡的最主要原因就是肿瘤的转移。应用目前的癌症检测手段往往出现的结果就是查出癌症的时候就已经是癌症中晚期了,极大的加大了治疗的难度,这也是癌症死亡率高居不下的一个重要原因。循环肿瘤细胞(Circulating Tumor Cells,CTCs)是指原发肿瘤组织或者转移灶上脱离并进入到肿瘤患者外周血循环中的肿瘤细胞。有研究表明,循环肿瘤细胞在肿瘤组织形成的早期就已经存在于外周血中,因而对肿瘤的早期诊断有很重要的临床研究价值。但是循环肿瘤细胞是血液中的稀有细胞,通常癌症患者每毫升外周血中仅仅含有几颗到几百颗循环肿瘤细胞却有着数十亿颗正常血细胞作为干扰细胞,因此从外周血中捕获循环肿瘤细胞仍然是个巨大的技术难题。免疫磁珠,是将特异性的单克隆抗体用生物或者化学的方法修饰到磁性颗粒表面形成既具有免疫学相关功能又具有磁性的颗粒。用免疫磁珠分离特定细胞的原理是连接在磁珠表面的特异性单克隆抗体能与目标细胞表面抗原特异性结合,在外加磁场中,目标细胞因为与磁珠相连被外磁场吸引而滞留在磁场中,非目标细胞由于不能与磁珠上特异性单抗结合而不与磁珠相连,因而没有磁性,不被外磁场吸引从而使目标细胞得以分离。然而应用这种方法分离的细胞表面仍然粘附有免疫磁珠,对后续深入的生物分子分析有不良影响。二氧化锰因为具有生物兼容性好,表面富含羟基易于功能化修饰等优点在生物研究领域有着很好的应用前景,不仅如此,二氧化锰可以被低浓度的草酸溶解。本文首先概括性的介绍了 CTCs的相关背景知识和目前常用的CTCs捕获手段。然后为了克服免疫磁珠捕获肿瘤细胞后磁珠仍然黏附在细胞上影响后续生化分析的缺点,我们制备了核壳结构四氧化三铁@二氧化锰纳米颗粒,然后在颗粒表面进行功能化修饰,嫁接上了 anti-EpCAM,实现了对肿瘤细胞的捕获。并且,通过低浓度草酸的处理,溶解了壳层的二氧化锰,实现了细胞的释放。最后对我们的研究工作进行了总结并对未来的工作方向进行了展望。
[Abstract]:Under the action of physical, chemical and biological tumorigenic factors, some tissues and cells lose their growth at the gene level, and the normal regulation of differentiation results in the destruction of normal tissues and organs without unlimited proliferation by physiological regulation of the body. Some tumor cells also metastasize to other organs to form metastatic foci. The main cause of death of cancer patients is the metastasis of the tumor. The result of using current methods of cancer detection is that the cancer is found at the middle and late stages of cancer, which greatly increases the difficulty of treatment. This is also an important reason for the high cancer mortality. Circulating Tumor cells (CTCs) are tumor cells that are isolated from primary tumor tissues or metastases and enter the peripheral blood circulation of cancer patients. Circulating tumor cells exist in peripheral blood at the early stage of tumor tissue formation, so they have important clinical value for early diagnosis of tumor. But circulating tumor cells are rare cells in blood. Cancer patients usually have only a few to hundreds of circulating tumor cells per milliliter of peripheral blood, but billions of normal blood cells as interfering cells. So capturing circulating tumor cells from peripheral blood is still a huge technical challenge. Specific monoclonal antibodies are modified to the surface of magnetic particles by biological or chemical methods to form particles that have both immunological and magnetic properties. The principle of separating specific cells from immunomagnetic beads is to attach them to the magnetic field. The specific monoclonal antibody on the bead surface can specifically bind to the surface antigen of the target cell. In the external magnetic field, the target cell is trapped in the magnetic field because it is attached to the magnetic beads and the non-target cells are not connected to the magnetic beads because they cannot bind to the specific monoclonal antibody on the magnetic beads. Not attracted by the external magnetic field, so that the target cells can be separated. However, the cells separated by this method still have immunomagnetic beads attached to the surface, which has a negative effect on the subsequent in-depth biomolecules analysis. The surface rich in hydroxyl groups is easy to functionalize and has a good application prospect in the biological research field, not only that, Manganese dioxide can be dissolved by low concentration of oxalic acid. This paper firstly introduces the background of CTCs and the current CTCs trapping methods. Then, in order to overcome the immune magnetic beads trapping tumor cells, the magnetic beads are still sticky. The disadvantages attached to the cell that affect subsequent biochemical analysis, We prepared core-shell Fe _ 2O _ 3 @ manganese dioxide nanoparticles, then functionalized the particles, grafted with anti-EpCAM to capture tumor cells, and treated with low concentration oxalic acid. The manganese dioxide in the shell layer was dissolved and the cell release was realized. Finally, our research work was summarized and the future work direction was prospected.
【学位授予单位】：武汉大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R730.4;TB383.1

【相似文献】