Foam-like compression behavior of fibrin networks.
Foam-like compression behavior of fibrin networks.
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DOI：
10.1007/s10237-015-0683-z
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发表时间：
2016-02
影响因子：
3.5
通讯作者：
Purohit PK
中科院分区：
文献类型：
--
作者：
Kim OV;Liang X;Litvinov RI;Weisel JW;Alber MS;Purohit PK
纤维蛋白网络的流变学性质一直是人们长期关注的问题。因此，有大量的研究，他们的剪切和拉伸响应，但他们的压缩行为仍然没有探索。在这里，通过表征的网络结构与同步测量的纤维蛋白存储和损耗模量在增加程度的压缩，我们表明，纤维蛋白网络的压缩行为是类似的细胞固体。纤维蛋白的非线性应力-应变响应由三种状态组成：1）初始线性状态，其中大多数纤维是直的，2）平台状态，其中越来越多的纤维屈曲和塌陷，以及3）显著非线性状态，其中通过屈曲引导的纤维的弯曲和纤维间接触发生网络致密化。重要的是，空间上不均匀的网络变形包括沿着应变轴沿着形成移动的“压缩前沿”，其将纤维蛋白网络分隔成具有不同纤维密度和结构的隔室。线性相的杨氏模量依赖于纤维蛋白体积分数的二次方，而在致密相依赖于它的三次方。粘弹性平台制度对应于这两个阶段的混合物中，这两个阶段的分数在压缩过程中的变化。我们这个政权使用连续理论的相变和分析预测的存储和损耗模量与实验数据吻合得很好。我们的工作表明，纤维蛋白网络是一个广泛的天然细胞材料，包括松质骨，木材和软木的成员。
The rheological properties of fibrin networks have been of long-standing interest. As such there is a wealth of studies of their shear and tensile responses, but their compressive behavior remains unexplored. Here, by characterization of the network structure with synchronous measurement of the fibrin storage and loss moduli at increasing degrees of compression, we show that the compressive behavior of fibrin networks is similar to that of cellular solids. A non-linear stress-strain response of fibrin consists of three regimes: 1) an initial linear regime, in which most fibers are straight, 2) a plateau regime, in which more and more fibers buckle and collapse, and 3) a markedly non-linear regime, in which network densification occurs by bending of buck-led fibers and inter-fiber contacts. Importantly, the spatially non-uniform network deformation included formation of a moving “compression front” along the axis of strain, which segregated the fibrin network into compartments with different fiber densities and structure. The Young’s modulus of the linear phase depends quadratically on the fibrin volume fraction while that in the densified phase depends cubically on it. The viscoelastic plateau regime corresponds to a mixture of these two phases in which the fractions of the two phases change during compression. We model this regime using a continuum theory of phase transitions and analytically predict the storage and loss moduli which are in good agreement with the experimental data. Our work shows that fibrin networks are a member of a broad class of natural cellular materials which includes cancellous bone, wood and cork.