Creating Dynamic and Adaptive Force-Producing Nanostructures

创建动态和自适应的力产生纳米结构非技术摘要：心肌可以可靠地运行一百多年，但产生收缩力的分子每隔几天就会更换一次。肌肉也会对锻炼做出反应，如果不使用，肌肉会萎缩。显然，大自然已经发展出了非常可靠和有效的方法，通过动态组织这种生物材料中的分子来产生力。拟议项目的目标是迈出在实验室中创建此类材料的第一步。为此，该项目将研究自然界在肌肉构建中使用的方法，并将其转化为由肌肉中使用的相同类型分子组装的人造材料的工程。其目标是证明可以创建“类似于肌肉”的结构，这些结构可以通过自动替换其老化部分来延长寿命，并且可以通过根据需要添加和释放部分来适应不断变化的条件。与传统的工程方法相比，例如，一辆持久的汽车是由更耐用的部件组装而成的，这种生物启发的方法可能会为工程带来巨大的好处。同时，它将帮助我们更好地了解构建肌肉和其他组织的自然方式。这种理解反过来又有助于医学对抗衰老和恢复身体功能的努力。除了获得新的研究见解，目的是激励和培养各级学生。例如，高中生和本科生的团队将被指导参加BIOMOD生物分子设计竞赛。技术摘要：未来的活性材料，组装成宏观力输出结构的分子马达，将必须基于支持提取功，不断再生和适应的自组织原理进行设计。本计画的目标是发现这些原理，并探讨它们在利用马达蛋白质作为产生力的分子组件的最小模型系统中的应用。为了使这些活性纳米结构在其活性分子组分的有限寿命之外保持功能状态，该项目将抽象出允许生物材料在远远超过组分寿命的时间内保持其功能的机制。特别是自组织和连续营业额的作用，以及所需的结构稳定性和易于更换的组件之间的平衡将进行调查。本研究的具体目标是：（1）建立一种动态平衡结构，其中微管由弱且可逆地结合到表面的驱动蛋白马达推动，（2）证明由于建立的动态平衡，适应变化的负载条件是可能的，以及（3）为了证明驱动蛋白马达向微管的动态募集降低了相对于静态的微管滑动所需的马达数量，在这种配置中，电机永久地粘附在表面上的任何地方。从这些实验的见解将反过来有助于发展一个理论上的理解，生物材料如何既防止和愈合损害，并将推广到新的合成和混合材料的设计。该项目将把本科生和高中生纳入研究过程，并旨在从代表性不足的群体中招收研究生。计划为当地K-12学生举办各种外联活动。该项目的成果将是潜在的转型，因为它旨在协助从耐用的人造结构（由同样耐用的纳米级组件组装而成）到耐用和自适应的工程结构（由短纤维组成）的范式转变。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的评估被认为值得支持。影响审查标准。

Creating dynamic and adaptive force-producing nanostructuresNon-Technical Abstract: The heart muscle can operate reliably for more than a hundred years, but the molecules which generate the force to contract are replaced every few days. Muscle also responds to exercise with growth and will shrink if not used. Clearly, nature has developed ways to produce force very reliably and efficiently by dynamically organizing the molecules in this biological material. The goal of the proposed project is to take the first steps towards creating such materials in the laboratory. To this end, this project will investigate the approaches used by nature in the construction of muscles, and translate them to the engineering of man-made materials assembled from the same type of molecules used in muscles. The goal is to show that structures can be created "similar to muscle" that can be long-lived by automatically replacing their aging parts and can adapt to changing conditions by adding and releasing parts as needed. Compared to the traditional engineering approach where, for example, a long-lasting car is assembled from even more durable components, this bio-inspired approach may offer great benefits for engineering. At the same time it will help us to better understand the natural way of constructing muscles and other tissues. This understanding in turn can contribute to efforts to combat aging and restore bodily functions in medicine. In addition to obtaining new research insights, the aim is to inspire and train students at all levels. For example, teams of high school and undergraduate students will be mentored to compete in the BIOMOD biomolecular design competition.Technical Abstract: Future active materials that assemble molecular motors into structures with macroscopic force output will have to be engineered based on self-organization principles supporting the extraction of work, constant regeneration, and adaptation. The goal of this project is to discover these principles and investigate their application in a minimal model system utilizing motor proteins as the force- producing molecular components. In order to maintain these active nanostructures in a functional state beyond the limited lifetime of their active molecular components, this project will abstract the mechanisms which allow biological materials to maintain their function for a duration far beyond the lifetime of the components. In particular the roles of self-organization and continuous turnover, and the balance between desired structural stability and ease of component replacement will be investigated. The specific objectives of this research are (1) to create a structure in dynamic equilibrium where microtubules are propelled by kinesin motors weakly and reversibly bound to a surface, (2) to demonstrate that adaptation to changing loading conditions is possible due to the dynamic equilibrium established, and (3) to demonstrate that the dynamic recruitment of kinesin motors to microtubules lowers the number of motors required for stable microtubule gliding relative to a static configuration where motors are permanently adhered everywhere on the surface. The insights from these experiments will in return assist in developing a theoretical understanding of how biological materials both prevent and heal damage, and will be generalizable for the design of novel synthetic and hybrid materials. The project will integrate undergraduate and high school students in the research process and aim to recruit graduate students from underrepresented groups. Various outreach activities to local K-12 students are planned. The outcome of the project will be potentially transformational in that it aims to assist in a paradigm shift from durable man-made structures assembled from equally durable nanoscale components to durable and adaptive engineered structures composed of short-lived nanoscale components with continuous replacement.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.