Stress controls the mechanics of collagen networks
Stress controls the mechanics of collagen networks
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DOI：
10.1073/pnas.1504258112
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发表时间：
2015-08-04
影响因子：
11.1
通讯作者：
MacKintosh, Fred C.
中科院分区：
文献类型：
--
作者：
Licup, Albert James;Muenster, Stefan;MacKintosh, Fred C.
胶原蛋白是各种结缔组织的主要结构和承重元素，在那里它形成支持细胞的细胞外基质。长期以来，人们一直知道胶原组织表现出高度非线性的应力-应变关系，尽管这种非线性的起源仍然未知。在这里，我们表明，重组I型胶原蛋白网络的非线性硬化是由所施加的应力和网络刚度变得令人惊讶的网络浓度不敏感。我们演示了如何一个简单的模型，弹性纤维网络可以定量地解释重建胶原蛋白网络的力学。我们的模型指出了法向应力在确定非线性剪切弹性响应中的重要作用，这可以解释胶原组织的应力和应变之间的近似指数关系。这进一步提出了具有胶原蛋白样性质的合成纤维网络的设计原则，以及控制这种网络的力学的机制。
Collagen is the main structural and load-bearing element of various connective tissues, where it forms the extracellular matrix that supports cells. It has long been known that collagenous tissues exhibit a highly nonlinear stress-strain relationship, although the origins of this nonlinearity remain unknown. Here, we show that the nonlinear stiffening of reconstituted type I collagen networks is controlled by the applied stress and that the network stiffness becomes surprisingly insensitive to network concentration. We demonstrate how a simple model for networks of elastic fibers can quantitatively account for the mechanics of reconstituted collagen networks. Our model points to the important role of normal stresses in determining the nonlinear shear elastic response, which can explain the approximate exponential relationship between stress and strain reported for collagenous tissues. This further suggests principles for the design of synthetic fiber networks with collagen-like properties, as well as a mechanism for the control of the mechanics of such networks.