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Electromechanical Properties and Deformation of Biomembranes

生物膜的机电特性和变形

基本信息

批准号：
1748049
负责人：
Petia Vlahovska
金额：
$ 22.4万
依托单位：
Northwestern University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-06-01 至 2020-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1748049&HistoricalAwards=false
关键词：
Electromechanical Properties Deformation Biomembranes

项目摘要

The cells of mammals, birds and reptiles have as their outer edge a thin layer, a cell membrane, that is composed of fatty molecules (lipids). The inside of the cell has a different concentration of charged molecules from the outside of the cell, resulting in an electric field across the membrane that changes its mechanical properties. The mechanical properties of the cell membrane have a profound effect upon how the cell functions. The research will determine by experiment how the mechanical properties of a cell membrane change as the result of exposure to electrical fields. The results of the experiments will be modeled using the engineering methods of 'shell theory' which can model the effects of the curvature of a thin material on its mechanical properties.An electric potential difference across the plasma membrane is common to all living cells and is essential to physiological functions such as generation of action potentials for cell-to-cell communication. While the basics of cell electrical activity are well established (e.g. the Hodgkin-Huxley model of the action potential), the coupling between voltage and membrane deformation has received limited attention. To fill this void, a combined theoretical and experimental study of biomimetic membranes in externally applied electric fields will be studied. Specifically, the research seeks to determine the relation between membrane voltage, membrane properties such as bending rigidity, tension, and spontaneous curvature, and membrane shape. The project integrates theory and experiment to analyze both the small thermally-driven bilayer undulations and the large buckling-like deformations in an applied electric field. The transformative impact of the project lies in its pioneering research of the dynamic coupling between shape and voltage of biomembranes; our findings will uncover new physics relevant to a broad range of physiological processes involving excitable cells.

哺乳动物、鸟类和爬行动物的细胞外缘有一层薄薄的细胞膜，由脂肪分子（脂质）组成。细胞内部的带电分子浓度与细胞外部不同，导致跨膜电场改变其机械性能。细胞膜的机械特性对细胞的功能具有深远的影响。该研究将通过实验确定细胞膜的机械性能如何因暴露于电场而发生变化。实验结果将使用“壳理论”的工程方法进行建模，该方法可以模拟薄材料的曲率对其机械性能的影响。质膜上的电位差对所有活细胞来说都是常见的，并且对于生理功能至关重要，例如产生用于细胞间通讯的动作电位。虽然细胞电活动的基础知识已经很好建立（例如动作电位的霍奇金-赫胥黎模型），但电压和膜变形之间的耦合受到的关注有限。为了填补这一空白，将对外部施加电场中的仿生膜进行理论和实验相结合的研究。具体来说，该研究旨在确定膜电压、膜特性（例如弯曲刚度、张力和自发曲率）以及膜形状之间的关系。该项目将理论和实验结合起来，分析施加电场中小的热驱动双层波动和大的屈曲状变形。该项目的变革性影响在于其对生物膜形状与电压之间动态耦合的开创性研究；我们的研究结果将揭示与涉及可兴奋细胞的广泛生理过程相关的新物理学。