Lee Andrea H, Elliott Dawn M
Department of Biomedical Engineering, University of Delaware, Newark, Delaware.
Ann N Y Acad Sci. 2017 Dec;1409(1):85-94. doi: 10.1111/nyas.13460. Epub 2017 Oct 25.
It is common in biomechanics to use previously frozen tissues, where it is assumed that the freeze-thaw process does not cause consequential mechanical or structural changes. We have recently quantified multiscale tendon mechanics and damage mechanisms using previously frozen tissue, where damage was defined as an irreversible change in the microstructure that alters the macroscopic mechanical parameters. Because freezing has been shown to alter tendon microstructures, the objective of this study was to determine if freezing alters tendon multiscale mechanics and damage mechanisms. Multiscale testing using a protocol that was designed to evaluate tendon damage (tensile stress-relaxation followed by unloaded recovery) was performed on fresh and previously frozen rat tail tendon fascicles. At both the fascicle and fibril levels, there was no difference between the fresh and frozen groups for any of the parameters, suggesting that there is no effect of freezing on tendon mechanics. After unloading, the microscale fibril strain fully recovered, and interfibrillar sliding only partially recovered, suggesting that the tendon damage is localized to the interfibrillar structures and that mechanisms of damage are the same in both fresh and previously frozen tendons.
在生物力学中，使用先前冷冻的组织很常见，人们认为冻融过程不会导致相应的力学或结构变化。我们最近使用先前冷冻的组织对多尺度肌腱力学和损伤机制进行了量化，其中损伤被定义为微观结构中改变宏观力学参数的不可逆变化。由于已经表明冷冻会改变肌腱微观结构，本研究的目的是确定冷冻是否会改变肌腱的多尺度力学和损伤机制。对新鲜和先前冷冻的大鼠尾腱束进行了多尺度测试，测试方案旨在评估肌腱损伤（拉伸应力松弛后进行无载恢复）。在束和纤维水平上新鲜组和冷冻组的任何参数均无差异，这表明冷冻对肌腱力学没有影响。卸载后，微观尺度的纤维应变完全恢复，而纤维间滑动仅部分恢复，这表明肌腱损伤局限于纤维间结构，并且新鲜和先前冷冻的肌腱损伤机制相同。
