Hatami-Marbini Hamed, Pachenari Mohammad
Computational Biomechanics Research Laboratory, Mechanical and Industrial Engineering Department, University of Illinois at Chicago, Chicago, IL, USA.
Computational Biomechanics Research Laboratory, Mechanical and Industrial Engineering Department, University of Illinois at Chicago, Chicago, IL, USA.
J Mech Behav Biomed Mater. 2020 Apr;104:103562. doi: 10.1016/j.jmbbm.2019.103562. Epub 2019 Dec 18.
It has been shown that there exists significance dependence between hydration and biomechanical properties of hydrated tissues such as cornea. The primary purpose of this study was to determine hydration effects on mechanical properties of sclera. Scleral strips, dissected from the posterior part of pig eyes along the superior-inferior direction, were divided into four hydration groups by first drying them and then soaking them in PBS until their hydration reached to 75%, 100%, 150%, and 200%. The strips were subjected to ten consecutive cycles of loading and unloading up to 1 MPa. The response of samples at the tenth cycle was used to compute the tangent modulus, maximum strain, and hysteresis as a function of hydration. The experiments were done in oil in order to prevent hydration changes during the mechanical tests. The mechanical response of strips right after dissection, control group, was also measured. In general, significant softening of scleral strips was found with increasing hydration (p < 0.05). The stress-strain response of control group was between those of samples with hydration 150% and 200%. The experimental stress-strain data were successfully represented numerically with an exponential mathematical relation with R > 0.99. The present study showed that hydration would significantly alter the tensile response of scleral tissue. Thus, the hydration of scleral specimens during mechanical experimental measurements should be carefully controlled.
研究表明，水合作用与诸如角膜等水合组织的生物力学特性之间存在显著相关性。本研究的主要目的是确定水合作用对巩膜力学性能的影响。从猪眼后部沿上下方向切取的巩膜条，先进行干燥处理，然后浸泡在磷酸盐缓冲液（PBS）中，直至其水合程度达到75%、100%、150%和200%，从而分为四个水合组。对这些条带施加高达1兆帕的连续十次加载和卸载循环。以第十个循环时样品的响应来计算切线模量、最大应变和滞后现象，并将其作为水合作用的函数。为了防止在力学测试过程中发生水合变化，实验在油中进行。还测量了刚解剖后的条带（对照组）的力学响应。总体而言，随着水合程度的增加，巩膜条带出现显著软化（p < 0.05）。对照组的应力 - 应变响应介于水合程度为150%和200%的样品之间。实验应力 - 应变数据成功地用指数数学关系进行了数值表示，相关系数R > 0.99。本研究表明，水合作用会显著改变巩膜组织的拉伸响应。因此，在力学实验测量过程中，应仔细控制巩膜标本的水合程度。
