配体介导的DNA纳米颗粒与细胞之间的相互作用研究

发布时间：2018-03-22 01:42

本文选题：DNA纳米结构　切入点：胆固醇　出处：《中国科学院研究生院(上海应用物理研究所)》2017年硕士论文　论文类型：学位论文

【摘要】：DNA是生物体遗传信息的载体,在生物的成长、发育、繁衍过程中发挥重要的作用。随着纳米技术的发展,DNA作为一种新兴材料可用于合成各种纳米结构。由于基于DNA的纳米结构有高度可定制的几何属性、很好的可寻址性和生物相容性,且容易进行化学修饰,是一类很有潜力的生物医学材料。但正常情况下,哺乳动物细胞对DNA材料的摄取效率较低,限制了其作为药物载体的应用。因此,本文研究了不同配体连接的DNA纳米结构与细胞的相互作用,尤其是配体连接策略对细胞摄取效率的影响,以增强DNA纳米结构进入细胞的效率。主要研究成果如下:(1)胆固醇修饰的DNA链促进DNA四面体的细胞摄取我们利用修饰有胆固醇的DNA链能锚定到细胞膜上的性质,提高与其序列互补的DNA四面体的细胞摄取。我们观察到,经胆固醇DNA介导的DNA四面体能快速富集到细胞的质膜表面,并快速被细胞摄取。在这一过程中,胆固醇DNA起到了类似于细胞表面受体的作用,因此我们将胆固醇DNA称为“人工DNA受体”。该受体介导的细胞摄取还具有特异性,只能介导带有互补序列手臂链的DNA四面体进入细胞。此外,我们还对DNA介导的摄取途径进行探索,发现其是小窝蛋白依赖的摄取途径。另外,我们发现,利用胆固醇DNA介导DNA四面体摄取的方式无明显细胞毒性,可用于提高DNA四面体运输载体的细胞摄取。此外,胆固醇DNA能促进载带阿霉素的DNA四面体进入细胞发挥药效,产生更强的细胞毒性。(2)DNA-纳米金核壳实现细胞内双模成像我们合成了具有空腔的DNA-纳米金核壳结构,空腔内可装载拉曼分子。这种DNA-纳米金核壳结构可实现细胞内双模成像,即拉曼成像和暗场成像。细胞对不同表面修饰的核壳结构的摄取效率不同,其中对同时修饰有DNA和RGD短肽的RGD/DNA-AuNPs摄取效率最高。
[Abstract]:DNA is the carrier of genetic information in organisms, in the growth and development of organisms, With the development of nanotechnology, DNA can be used as a new material to synthesize various nanostructures. Because nanostructures based on DNA have highly customizable geometric properties, Highly addressable, biocompatible and easily chemically modified, it is a promising biomedical material. However, under normal conditions, mammalian cells have low uptake efficiency of DNA materials. Therefore, the interaction between different ligand DNA nanostructures and cells was studied, especially the effect of ligand binding strategy on cell uptake efficiency. In order to enhance the efficiency of DNA nanostructures entering into cells. The main research results are as follows: 1) Cholesterol-modified DNA chains promote the uptake of DNA tetrahedron cells by using DNA chains modified with cholesterol to anchor to cell membranes. We observed that DNA tetrahedron mediated by cholesterol DNA can rapidly enrich to the surface of the plasma membrane of the cell and be rapidly ingested by the cell. Cholesterol DNA acts as a cell surface receptor, so we call cholesterol DNA an "artificial DNA receptor." the receptor also mediates cellular uptake. Only DNA tetrahedrons with complementary arm chains can be mediated into cells. In addition, we have explored the uptake pathway mediated by DNA and found that it is a fossa protein-dependent uptake pathway. Cholesterol DNA mediated DNA tetrahedron uptake was not cytotoxic and could be used to increase the cellular uptake of DNA tetrahedron transport vector. In addition, cholesterol DNA could promote the entry of DNA tetrahedron carrying adriamycin into cells. To produce more cytotoxic DNA-nanocrystalline gold core-shell cells, we have synthesized DNA-nano-gold core-shell structures with cavities, which can hold Raman molecules in the cavity. This DNA-nano-gold core-shell structure can be used for intracellular dual-mode imaging. That is Raman imaging and dark field imaging. Cell uptake efficiency of core-shell structure with different surface modification is different. Among them the uptake efficiency of RGD/DNA-AuNPs modified with DNA and RGD short peptides is the highest.
【学位授予单位】：中国科学院研究生院(上海应用物理研究所)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;Q25

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