经过三十多年的研究与发展，DNA纳米技术日臻成熟，DNA纳米材料逐渐成为强有力的工具，在各研究领域中发挥着独特的功能。在这样的研究背景下，设计开发新的、多样的复杂DNA纳米结构以适应不同的具体下游应用，已经成为DNA纳米科技领域内一项重要的研究方向。 本论文中我们提出了简易型模块化DNA折纸结构的构建方法，结构由多个模块构成，模块间由平行排列的支架DNA连接。我们成功构建了多个基础二维和三维结构，探究了不同设计参数对结构形态和性质的影响。我们对基础结构进行了基于模块的平移、翻转、延长、弯折等改造，获得了高复杂度的结构。 我们发现结构具有双重构象，两种构象下结构内DNA双螺旋的排列方向相互垂直。结构构象由一些特殊的支架DNA决定，特殊支架DNA可以加强结构边缘DNA双螺旋的刚性，进而影响整体双螺旋的走向。已经完成组装的结构仍然可以进行构象转化。 我们发现二维的结构DNA双螺旋数越少，组装速度越快。我们提出并证明了决定结构组装速度的机制：支架DNA的两个结合区在骨架DNA上的结合位置相距越近，支架DNA的结合倾向越强，结合倾向强的支架DNA越多，结构的自组装速度越快。 我们还提出了线框型模块化结构的设计方法，构建了具有六臂分支单元的二维线框结构和具有四臂分支单元的三维线框结构，并对结构进行了基于模块的改造。
Over the past three decades, tremendous progress has been made in DNA nanotechnology field, and DNA nanostructures have become a powerful tool in various research fields. One of the most important research subjects is to design and construct more DNA nanostructures to satisfy diverse downstream applications. Here we introduce a simplified architecture to design origami nanostructures with modules connected by parallel staples. A series of basic two-dimensional and three-dimensional structures are successfully constructed. The influence of different designing parameters on the structure shape and property is explored. As the structures can be virtually divided into blocks, modular remodeling such as translocation, extension, and bending is carried out.We discover that structures under such a designing framework have two conformations. The orientation of DNA helices in one conformations is perpendicular to the other. The conformation of structures depends on some special staples, which can enhance the stiffness of DNA helices at the edge of structures and thus decide the orientation of all helices. Conformation of assembled structures can be changed. We find that structures with less DNA helices assemble faster, and have revealed the mechanism of this phenomenon. The distance between the two binding sites, which can pair with the two binding domains of each staple, decides the binding propensity of the staple. If the proportion of staples with high binding propensity is large, the structure assembles fast.We also propose a modular architecture to design wireframe origami nanostructures. We constructed a two-dimensional wireframe structure with 6-arm junctions and a three-dimensional wireframe structure with special 4-arm junctions. The two basic structures were remodeled in a modular way.
