Nonlinear elasticity in biological gels
Nonlinear elasticity in biological gels
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DOI：
10.1038/nature03521
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发表时间：
2005-05-12
期刊：
影响因子：
64.8
通讯作者：
Janmey, PA
中科院分区：
文献类型：
--
作者：
Storm, C;Pastore, JJ;Janmey, PA
生物软组织的力学性能对其生理功能至关重要，合成材料不易复制。与简单的聚合物凝胶不同，许多生物材料--包括血管(1)、肠系膜组织(2)、肺实质(3)、角膜(4)和血块(5)--在拉伸时会变硬，从而防止可能威胁组织完整性的大变形。这种非线性弹性的分子结构和设计原理尚不清楚。在这里，我们报告了一个分子理论，它解释了由细胞骨架和细胞外蛋白形成的一系列分子上不同的凝胶中的应变硬化，并揭示了在低到中等应变下普遍存在的应力-应变关系。这一理论的输入是单个半柔性细丝的力-伸长曲线，以及假设由这些细丝组成的生物网络是均匀、各向同性的，并且它们是均匀应变的。这一理论表明，排列在开放的交联网中的丝状蛋白质系统在低应变下总是变硬的，而不需要特定的结构或具有不同固有刚性的多个元件。
The mechanical properties of soft biological tissues are essential to their physiological function and cannot easily be duplicated by synthetic materials. Unlike simple polymer gels, many biological materials - including blood vessels(1), mesentery tissue(2), lung parenchyma(3), cornea(4) and blood clots(5) - stiffen as they are strained, thereby preventing large deformations that could threaten tissue integrity. The molecular structures and design principles responsible for this nonlinear elasticity are unknown. Here we report a molecular theory that accounts for strain-stiffening in a range of molecularly distinct gels formed from cytoskeletal and extracellular proteins and that reveals universal stress - strain relations at low to intermediate strains. The input to this theory is the force - extension curve for individual semi-flexible filaments and the assumptions that biological networks composed of these filaments are homogeneous, isotropic, and that they strain uniformly. This theory shows that systems of filamentous proteins arranged in an open crosslinked mesh invariably stiffen at low strains without requiring a specific architecture or multiple elements with different intrinsic stiffness.