Micro- and Nano-Mechanics of Active Biopolymer Networks

活性生物聚合物网络的微观和纳米力学

• 批准号: 0800533
• 负责人: Alexander Levine
• 金额: $ 32万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0800533&HistoricalAwards=false
• 关键词: Micro; Nano; Mechanics; Active; Biopolymer

The research objective of this award is to develop new analytic and numerical approaches to examine the complex relationship of filament mechanics and network structure to the collective elastic properties of semiflexible networks. Semiflexible networks are cross-linked aggregates of stiff polymers. They are fundamentally different from the better understood polymeric materials that are the usual products of modern synthetic chemistry. Under applied stress semiflexible networks can store elastic energy in both the stretching and bending of the constituent filaments, while traditional polymer networks, which are composed of highly flexible polymer chains, store elastic energy only in filament stretching. The most common example of a semiflexible network is found in the cytoskeleton of living cells. There stiff protein filaments (F-actin) are cross-linked to form a stress-bearing framework that gives the cell its mechanical rigidity. Recent experiments have shown that small changes in network architecture and in the action of molecular motors can lead to significant changes the elasticity of these F-actin networks. This research will explore in detail how these changes in network structure and non-equilibrium steady-state (via the action of the molecular motors) leads to large mechanical changes of the network. Among the benefits of the successful completion of this work will be a deeper understanding of the design principles for building a new class of light-weight, mechanically tunable materials. The theory will also address new biomimetic approaches to materials design that use the action of endogenous motors to tune mechanical properties through the modification of the materials non-equilibrium steady-state. Such research will enable the creation of new bio-compatible materials whose mechanical properties can be precisely controlled. These materials may find applications in the promotion of wound healing. Finally, this research will assist the training of students/postdocs working at the interface of the physics, biology, and engineering.

该奖项的研究目标是开发新的分析和数值方法，以研究细丝力学和网络结构与半柔性网络的集体弹性特性之间的复杂关系。半柔性网络是刚性聚合物的交联聚集体。它们与现代合成化学的常见产品、更容易理解的聚合物材料有着根本的不同。 在施加的应力下，半柔性网络可以在组成长丝的拉伸和弯曲过程中存储弹性能，而由高度柔性的聚合物链组成的传统聚合物网络仅在长丝拉伸时存储弹性能。半柔性网络最常见的例子是在活细胞的细胞骨架中。坚硬的蛋白丝（F-肌动蛋白）交联形成承压框架，赋予细胞机械刚性。 最近的实验表明，网络结构和分子马达作用的微小变化可以导致这些 F-肌动蛋白网络的弹性发生显着变化。 这项研究将详细探讨网络结构和非平衡稳态（通过分子马达的作用）的这些变化如何导致网络的巨大机械变化。成功完成这项工作的好处之一是可以更深入地了解构建新型轻质、机械可调材料的设计原理。该理论还将提出新的材料设计仿生方法，利用内源马达的作用，通过修改材料的非平衡稳态来调整机械性能。此类研究将能够创造出机械性能可以精确控制的新型生物相容材料。这些材料可用于促进伤口愈合。 最后，这项研究将有助于培训在物理学、生物学和工程学领域工作的学生/博士后。