Nonlinear time-dependent mechanical behavior of mammalian collagen fibrils.
Nonlinear time-dependent mechanical behavior of mammalian collagen fibrils.
复制标题
哺乳动物胶原纤维的非线性时间依赖性机械行为。
DOI：
10.1016/j.actbio.2022.03.005
复制
发表时间：
2023
影响因子：
9.7
通讯作者：
Chasiotis,Ioannis
中科院分区：
文献类型：
--
作者：
Yang,Fan;Das,Debashish;Karunakaran,Kathiresan;Genin,GuyM;Thomopoulos,Stavros;Chasiotis,Ioannis
胶原组织的粘弹性力学行为已经在宏观尺度上得到了广泛的研究，但对组织的基本构建块胶原纤维的时间依赖性力学的彻底定量理解仍然缺失。为了解决这一知识缺口，在各种应力（5-35 MPa）和应变（5-20%）水平下对磷酸盐缓冲盐水（PBS）中的单个胶原原纤维（完全水合原纤维的平均直径：253 ± 21 nm）进行应力松弛和蠕变试验。实验结果表明，完全水合的个人胶原蛋白原纤维重建从I型小牛皮肤胶原蛋白的时间依赖性的力学行为，是由应变依赖的应力松弛和应力依赖的蠕变功能在两个脚跟脚趾和线性制度的变形在单调的应力-应变曲线。自适应准线性粘弹性（QLV）模型，最初开发捕捉胶原组织的非线性粘弹性响应，提供了一个非常好的描述的非线性应力松弛和蠕变行为的胶原纤维。另一方面，非线性叠加（NSP）模型拟合蠕变，但不是应力松弛数据。分别从自适应QLV和NSP模型中提取的时间常数和速率表明，应力松弛的速率比蠕变快。这种非线性粘弹性行为的个别胶原纤维同意与先前的研究macrocale的胶原组织，从而证明了一致的时间依赖性行为的长度尺度和组织hierarchies.Statement的显著性纯应力松弛和蠕变实验进行了第一次与完全水合的个别胶原纤维。结果表明，胶原纳米原纤维具有非线性的时间依赖性行为，这与先前对宏观胶原组织的研究一致，从而证明了跨长度尺度和组织层次的一致的时间依赖性行为。这种对哺乳动物胶原组织构建块的非线性粘弹性行为的新见解可以作为改进宏观尺度组织模型的基础，该模型捕获跨长度尺度的机械行为。
The viscoelastic mechanical behavior of collagenous tissues has been studied extensively at the macroscale, yet a thorough quantitative understanding of the time-dependent mechanics of the basic building blocks of tissues, the collagen fibrils, is still missing. In order to address this knowledge gap, stress relaxation and creep tests at various stress (5-35 MPa) and strain (5-20%) levels were performed with individual collagen fibrils (average diameter of fully hydrated fibrils: 253 ± 21 nm) in phosphate buffered saline (PBS). The experimental results showed that the time-dependent mechanical behavior of fully hydrated individual collagen fibrils reconstituted from Type I calf skin collagen, is described by strain-dependent stress relaxation and stress-dependent creep functions in both the heel-toe and the linear regimes of deformation in monotonic stress-strain curves. The adaptive quasilinear viscoelastic (QLV) model, originally developed to capture the nonlinear viscoelastic response of collagenous tissues, provided a very good description of the nonlinear stress relaxation and creep behavior of the collagen fibrils. On the other hand, the nonlinear superposition (NSP) model fitted well the creep but not the stress relaxation data. The time constants and rates extracted from the adaptive QLV and the NSP models, respectively, pointed to a faster rate for stress relaxation than creep. This nonlinear viscoelastic behavior of individual collagen fibrils agrees with prior studies of macroscale collagenous tissues, thus demonstrating consistent time-dependent behavior across length scales and tissue hierarchies.Statement of significancePure stress relaxation and creep experiments were conducted for the first time with fully hydrated individual collagen fibrils. It is shown that collagen nanofibrils have a nonlinear time-dependent behavior which agrees with prior studies on macroscale collagenous tissues, thus demonstrating consistent time-dependent behavior across length scales and tissue hierarchies. This new insight into the non-linear viscoelastic behavior of the building blocks of mammalian collagenous tissues may serve as the foundation for improved macroscale tissue models that capture the mechanical behavior across length scales.