【作者】 李俊；

【导师】 吴钰周；

【作者基本信息】 华中科技大学 ， 化学生物学， 2021， 硕士

【摘要】 纳米结构可以有效提高药物在固体肿瘤组织的摄取及选择性积累,是一种很有前景的抗肿瘤治疗手段。并且,研究发现通过改变纳米结构性质,如尺寸、形状、表面电荷等,可以有效改变纳米结构在肿瘤组织中的转运及递送。由于体内复杂环境的干扰及不同材料体系之间的差异,这些研究现阶段还没有得出统一的结论。因此,借助相对简单的体外三维模型,系统地探究纳米结构的物理化学性质对其在肿瘤组织中穿透及积累的影响尤为必要。但是传统的纳米结构制备手段往往难以利用同一种材料同时满足形状与表面物理化学性质调控的需求,而DNA折纸术具有强大的形状可设计性、优异的可寻址性及易于功能化等特点,是解决上述问题的理想方案。基于DNA折纸术,本文设计了一系列不同形状、亲疏水及电荷改性的DNA折纸纳米结构(DNs),并利用非支架法构建了三维肿瘤多细胞球(MCSs),系统地探究了形状、亲疏水及表面电荷对纳米结构在MCSs中摄取及穿透的影响,主要研究工作如下:(1)基于DNA折纸术构建了五种不同形状的DNs,细胞试验结果表明较小长宽比有利于单层细胞对DNs的摄取,而较小的尺寸及较大的长宽比有利于DNs在MCSs中的摄取及穿透。此外,DNs仅被外围细胞摄取,难以穿透到MCSs内部;(2)通过在DNA折纸纳米棒(Rod)表面引入不同数量的ss DNA-lipid疏水分子,证明适量疏水分子的引入能够显著提高纳米结构在MCSs中的穿透效率,但疏水修饰比例过高会引起Rod纳米结构的团聚,从而降低其穿透效率和穿透深度;(3)通过静电吸附和原子转移自由基聚合(ATRP)分别构造了整体呈现正电性的c HSA-Tile纳米结构和局部区域化正电荷改性的C-Tile纳米结构,研究发现,c HSA的包裹可以显著提高DNs在MCSs中的摄取效率,而C-Tile纳米结构不仅具有较高的摄取效率,还能均匀地穿透至MCSs内部。更多还原

【Abstract】 Nanostructures can effectively improve the uptake and selective accumulation of drugs in solid tumor tissues,and become a promising means of anti-tumor therapy.What’s more,researches have found that the transport and delivery of nanostructures in tumor tissues can be effectively improved by regulating the properties of nanostructures,such as size,shape,surface charge and so on.Due to the interference of complex environments in vivo and the differences between different material systems,these studies have not reached a unified conclusion at this stage.Therefore,with the help of a relatively simple three-dimensional model in vitro,it is imperative to investigate the effects of the physical and chemical properties of nanostructures on their penetration and accumulation in tumor tissues systematically.However,the traditional method of nanostructures preparation is often difficult to use the same material to meet the requirements of shape and surface physical and chemical properties regulate at the same time.Whereas DNA origami has the characteristics of powerful shape designability,excellent addressability and easy functionalization,so it is an ideal solution to deal with these above problems.In this paper,a series of DNA origami nanostructures(DNs),with different shapes,hydrophobicity and charge modification were designed based on DNA origami,and three-dimensional tumor multicellular spheres(MCSs)were constructed by the non-scaffold method.The effects of shape,hydrophobicity and surface charge on the uptake and penetration of nanostructures in MCSs were systematically explored.The main research results are as follows:(1)DNs with five different shapes were constructed based on DNA origami.The results of cell experiments showed that smaller aspect ratio was beneficial to monolayer cell uptake of DNs,however in MCSs,smaller size and larger aspect ratio were beneficial to DNs uptake and penetration.In addition,the DNA origami structure was only internalized by peripheral cells,it was difficult to penetrate into the interior of MCSs.(2)By introducing different numbers of ss DNA-lipid hydrophobic molecules into the surface of DNA origami nanorods(Rod),it was proved that the penetration efficiency of nanostructures in MCSs could be significantly improved by introduced appropriate amount of hydrophobic molecules.Nevertheless,too high proportion of hydrophobic modification would cause the agglomeration of Rod nanostructures,thus reducing the penetration efficiency and penetration depth in MCSs.(3)The c HSA-Tile nanostructure with the overall positive electricity and the C-Tile nanostructure modified by partial regionalized positive charge were constructed by electrostatic adsorption and atom transfer radical polymerization(ATRP),respectively.The experimental results showed that the coated of c HSA could significantly improve the uptake efficiency of DNs in MCSs,while the C-Tile nanostructure not only had higher uptake efficiency,but also could evenly penetrate into MCSs.更多还原