The micro-structural strain response of tendon
The micro-structural strain response of tendon
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DOI：
10.1007/s10853-007-1653-3
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发表时间：
2007-11-01
影响因子：
4.5
通讯作者：
Screen, Hazel R. C.
中科院分区：
文献类型：
--
作者：
Cheng, Vinton W. T.;Screen, Hazel R. C.
肌腱是一种多层纤维增强复合材料，旨在将肌肉力量传递到骨骼。在生理负荷期间，肌腱经历拉伸负荷，这些负荷通过结构传递到细胞，在那里它们可能启动机械转导路径。目前的研究考察了在拉伸载荷下肌腱基质内的结构重组和由此产生的局部应变场。它使用共聚焦显微镜将网格光漂白到胶原上，并在增量拉伸应变的作用下成像其变形。六个参数被用来量化纤维和纤维的运动，并检查了束状纤维的伸展机制。结果表明，整个基质中的应变响应不均匀，样品之间的变异性很大。加载轴上的局部应变明显小于应变值。然而，垂直于加载轴的大的压缩应变被记录下来。平均泊松比(0.8)表明细胞在加载过程中可能会经历显著的压缩。网格线的偏转，表明胶原纤维之间的滑动，以及网格的旋转也被记录下来。这些数据突出了纤维束的非均匀应变环境，并为纤维在拉伸载荷下滑动提供了进一步的证据。他们还提出了肌腱反应的旋转成分，这可能表明肌腱基质的螺旋组织。
Tendons are multi-level fibre-reinforced composites, designed to transmit muscle forces to the skeleton. During physiological loading, tendons experience tensile loads, which are transmitted through the structure to the cells, where they may initiate mechanotransduction pathways. The current study examines the structural reorganisation and resulting local strain fields within the tendon matrix under tensile load. It uses confocal microscopy to photobleached a grid onto the collagen and image its deformation under the application of incremental tensile strain. Six parameters are used to quantify fibril and fibre movement and examine the mechanisms of extension employed by fascicles.Results demonstrated an inhomogeneous strain response throughout the matrix and large variability between samples. Local strains in the loading axis were significantly smaller than the applied values. However, large compressive strains, perpendicular to the loading axis, were recorded. The average Poisson's ratio (0.8) suggested cells may experience significant compression during loading. Deflection of the grid lines, indicating sliding between collagen fibres, and rotation of the grid were also recorded. These data highlight the non-homogenous strain environment of fascicles and provide further evidence for fibre sliding under tensile load. They also suggested a rotary component to tendon response, which may indicate a helical organisation to the tendon matrix.