Supramolecular DNA Structures: From Design to Function

*我们在过去6年的研究中，在超分子化学和DNA纳米技术领域取得了几项发现。这些包括：*(A)包裹治疗药物并选择性地释放它们的DNA笼子，只有当它们遇到存在于癌细胞中的分子，并且具有良好的体外和体内这些结构的性质时，才能有选择地释放它们。*(B)观察到，DNA纳米结构可用作临时“印刷机”，而不是永久支架，并可将其结构信息转移到金粒子和聚合物上。这引入了超分子信息可以从一种材料化学传输到另一种材料的概念。*(C)扩展DNA碱基配对密码的另一种方法，通过添加一个小的氢键分子，将DNA碱基配对重新编程为“玫瑰花环”基序。*(D)一类新的单分散和顺序可控的聚合物，采用自动固相DNA合成工具合成。将它们与DNA纳米结构相结合，产生了任何一种材料都无法获得的紧急组装模式。*(E)通过控制其组件的添加顺序来构建复杂的DNA结构，然后这些组件可以重复使用，从而使用时间控制来实现复杂性。*本提案描述了利用DNA组装为两类重要材料带来前所未有的结构定义和动态特性：合成聚合物和脂类双层。*DNA纳米结构与脂质双层膜的相互作用。DNA笼在传感、成像和药物输送应用方面具有巨大的潜力。当它们与细胞相互作用时，它们遇到的第一个界面是脂质双层膜，因此了解这一过程对于将它们转化为生物应用是至关重要的。在这个方案中，我们研究了DNA纳米结构与脂质双层的相互作用，并开发了这些材料的两个应用：作为膜纳米孔用于生物分子检测，以及作为‘筏’介导细胞附着和调节膜曲率。*分子“打印”在具有DNA结构的聚合物上。我们将建立在我们最近的发现的基础上，DNA纳米结构可以用作临时模板，或“印刷机”。人们对增加聚合物纳米结构的复杂性有极大的兴趣和巧妙的方法。然而，DNA的结构定义及其可编程性在聚合物化学中是无与伦比的。我们将描述使用DNA结构作为模板，以2D和3D形式将DNA图案共价连接到聚合纳米颗粒上，并通过DNA“成型”策略控制它们的大小和形状。这导致了前所未有的聚合物粒子以定向的方式组装，也就是原子聚集成分子的方式，从而极大地提高了聚合物自组装的控制水平和可编程性。

***Our research during the last 6 years has led to several discoveries in the fields of supramolecular chemistry and DNA nanotechnology. These include:******(a) DNA cages that encapsulate therapeutics and release them selectively, only when they encounter a molecule that is present in cancer cells, and that have favorable in vitro and in vivo properties of these structures. ***(b) the observation that DNA nanostructures can be used as a temporary “printing press” rather than a permanent scaffold, and can transfer their structural information to gold particles and polymers. This introduces the notion that supramolecular information can be chemically transmitted from one material to another. ***(c) an alternative method to expand the DNA base-pairing code, by adding a small hydrogen-bonding molecule that reprograms DNA base-pairing into a “rosette” motif.***(d) a new class of polymers which are monodisperse and sequence-controlled, synthesized by adapting the tools of automated solid-phase DNA synthesis. Combining them with DNA nanostructures leads to emergent assembly modes which could not have been obtained by either material.***(e) the building of complex DNA structures by controlling the order of addition of their components which can then be re-used, thus using temporal control to achieve complexity. ******This proposal describes the use of DNA assembly to bring unprecedented structural definition and dynamic character to two important classes of materials: synthetic polymers and lipid bilayers. ******Interaction of DNA nanostructures with lipid bilayer membranes. DNA cages have tremendous potential for sensing, imaging, and drug delivery applications. The first interface that they encounter when they interact with cells are lipid bilayer membranes, and thus understanding this process is essential to transition them to biological applications. In this proposal, we examine the interaction of DNA nanostructures with lipid bilayers and develop two applications for these materials: as membrane nanopores for biomolecule detection, and as ‘rafts' to mediate cell attachment and tune membrane curvature.******Molecular “Printing” on Polymers with DNA Structures. We will build upon our recent discovery that DNA nanostructures can be used as a temporary template, or a “printing press”. There has been tremendous interest and elegant methods to increase the complexity of polymer nanostructures. However, the structural definition of DNA and its programmability are unmatched in polymer chemistry. We will describe the use of DNA structures as templates to covalently attach DNA patterns to polymeric nanoparticles in 2D- and 3D-, and to control their size and shape with DNA ‘molding' strategies. This results in unprecedented polymer particles that assemble in a directional manner, the way that atoms come together to make molecules, thus dramatically increasing the level of control and programmability in polymer self-assembly.