Tropocollagen springs allow collagen fibrils to stretch elastically.
Tropocollagen springs allow collagen fibrils to stretch elastically.
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DOI：
10.1016/j.actbio.2022.01.041
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发表时间：
2022-04-01
影响因子：
9.7
通讯作者：
Meek KM
中科院分区：
文献类型：
--
作者：
Bell JS;Hayes S;Whitford C;Sanchez-Weatherby J;Shebanova O;Terrill NJ;Sørensen TLM;Elsheikh A;Meek KM
结缔组织的机械特性是根据其特定功能定制的，并且变化可能导致功能障碍和病理学。在大多数哺乳动物组织中，力学环境由胶原蛋白的微米和纳米尺度结构及其与其他组织组分的相互作用决定，然而这些分级性质仍然知之甚少。在这项研究中，我们使用人类角膜作为一个模型系统，以确定和量化的主要变形机制的结缔组织响应于循环负荷的生理幅度。同步生物力学测试，X射线散射和3D数字图像相关性揭示了两种主要机制的存在：胶原纤维伸长，由于很大程度上弹性，弹簧样拉直原胶原超分子扭曲，和更粘的拉直纤维卷曲，逐渐增加了连续的负载循环。这两种机制的不同机械特性表明它们在体内具有不同的作用。弹性的弹簧状机构是快速作用的，并且可能响应与心动周期相关的应力，而更粘性的卷曲机构将响应较慢的过程，例如姿势应力。预计这些发现将具有广泛的适用性，以了解其他结缔组织，如皮肤和血管，表现出螺旋结构和卷曲的正常和病理功能。原胶原弹簧机制允许来自某些组织的胶原纤维在小载荷下显著伸长，并且其最近的发现有可能改变我们对组织如何变形的基本理解。这种时间分辨的研究量化了弹簧机制对拉伸组织中局部应变的贡献，并将其与被广泛接受的主要低负荷应变机制--原纤维波纹度拉直相关的贡献进行了比较。弹簧机制比原纤维拉直对局部组织应变的贡献更大，并且被发现是弹性的，而原纤维拉直更粘稠。结果表明，粘弹性行为的生物材料的控制，至少部分地，由纤维规模卷曲和原胶原超分子扭曲的相对量。
The mechanical properties of connective tissues are tailored to their specific function, and changes can lead to dysfunction and pathology. In most mammalian tissues the mechanical environment is governed by the micro- and nano-scale structure of collagen and its interaction with other tissue components, however these hierarchical properties remain poorly understood. In this study we use the human cornea as a model system to characterise and quantify the dominant deformation mechanisms of connective tissue in response to cyclic loads of physiological magnitude. Synchronised biomechanical testing, x-ray scattering and 3D digital image correlation revealed the presence of two dominant mechanisms: collagen fibril elongation due to a largely elastic, spring-like straightening of tropocollagen supramolecular twist, and a more viscous straightening of fibril crimp that gradually increased over successive loading cycles. The distinct mechanical properties of the two mechanisms suggest they have separate roles in vivo. The elastic, spring-like mechanism is fast-acting and likely responds to stresses associated with the cardiac cycle, while the more viscous crimp mechanism will respond to slower processes, such as postural stresses. It is anticipated that these findings will have broad applicability to understanding the normal and pathological functioning of other connective tissues such as skin and blood vessels that exhibit both helical structures and crimp. The tropocollagen spring mechanism allows collagen fibrils from some tissues to elongate significantly under small loads, and its recent discovery has the potential to change our fundamental understanding of how tissue deforms. This time-resolved study quantifies the contribution of the spring mechanism to the local strain in stretched tissue and compares it to the contribution associated with the straightening of fibril waviness, the widely accepted primary low-load strain mechanism. The spring mechanism contributed more to the local tissue strain than fibril straightening, and was found to be elastic while fibril straightening was more viscous. The results suggest that the viscoelastic behaviour of a biomaterial is controlled, at least in part, by the relative amount of fibril-scale crimp and tropocollagen supramolecular twist.
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影响因子：
5.7
作者：
Aghamohammadzadeh, H;Newton, RH;Meek, KM
通讯作者：
Meek, KM
影响因子：
3.9
作者：
Hayes, Sally;White, Tomas;Meek, Keith M.
通讯作者：
Meek, Keith M.
DOI：
10.1016/j.nima.2009.03.200
发表时间：
2009-08-01
影响因子：
1.4
作者：
Henrich, B.;Bergamaschi, A.;Schmitt, B.
通讯作者：
Schmitt, B.
影响因子：
3.4
作者：
Lewis PN;White TL;Young RD;Bell JS;Winlove CP;Meek KM
通讯作者：
Meek KM
影响因子：
3.7
作者：
Bakker EN;Groma G;Spijkers LJ;de Vos J;van Weert A;van Veen H;Everts V;Arribas SM;VanBavel E
通讯作者：
VanBavel E