Collagen cross-linking treatment effects on corneal dynamic biomechanical properties
Collagen cross-linking treatment effects on corneal dynamic biomechanical properties
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DOI：
10.1016/j.exer.2015.04.005
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发表时间：
2015-06-01
影响因子：
3.4
通讯作者：
Rahimi, Abdolrasol
中科院分区：
文献类型：
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作者：
Hatami-Marbini, Hamed;Rahimi, Abdolrasol
角膜是一种软组织，其主要功能是透射和折射光线。本研究的目的是表征核黄素/UVA胶原交联对角膜动态特性的可能影响。原始角膜交联方案用于诱导牛角膜前部的交联。使用DMA机器在不同水平的拉伸应变下进行机械拉伸实验。将样品分为对照组（n = 5）和处理组（n = 5）。首先将所有试样拉伸至5%的应变，并使其松弛20分钟。在完成应力松弛实验之后，进行具有范围从0.01至10 Hz的振荡的频率扫描测试。重复相同的过程以获得在10%应变下的应力松弛和动态特性。结果表明，胶原交联处理显著提高了牛角膜的即刻和平衡拉伸性能（P < 0.05）。此外，对于对照组和处理组中的所有样品以及在整个频率范围内，与在5%的拉伸应变下获得的拉伸储能模量相比，在10%的轴向应变下测量到显著更大的拉伸储能模量。最后，注意到尽管该处理程序导致在任何轴向应变和频率下的储能和损耗模量的显著增加（P < 0.05），但其显著降低了在单个变形循环期间耗散能量和储存能量的比率。因此，可以得出结论，虽然核黄素/UVA胶原交联显著增加了角膜硬度，但其显著降低了其阻尼能力和变形能力。这种降低的阻尼能力可能不利地干扰角膜机械性能。(C)2015爱思唯尔有限公司版权所有。
Cornea is a soft tissue with the principal function of transmitting and refracting light rays. The objective of the current study was to characterize possible effects of the riboflavin/UVA collagen cross-linking on corneal dynamic properties. The original corneal cross-linking protocol was used to induce cross-links in the anterior portion of the bovine cornea. A DMA machine was used to conduct mechanical tensile experiments at different levels of tensile strains. The samples were divided into a control group (n = 5) and a treated group (n = 5). All specimens were first stretched to a strain of 5% and allowed to relax for twenty minutes. After completion of the stress-relaxation experiment, a frequency sweep test with oscillations ranging from 0.01 to 10 Hz was performed. The same procedure was repeated to obtain the stress-relaxation and dynamic properties at 10% strain. It was observed that the collagen cross-linking therapy significantly increased the immediate and equilibrium tensile behavior of the bovine cornea (P < 0.05). Furthermore, for all samples in control and treated groups and throughout the whole range of frequencies, a significantly larger tensile storage modulus was measured at an axial strain of 10% compared to what was obtained at a tensile strain of 5%. Finally, it was noted that although this treatment procedure resulted in a significant increase in the storage and loss modulus at any axial strain and frequency (P < 0.05), it significantly reduced the ratio of the dissipated and stored energy during a single cycle of deformation. Therefore, it was concluded that while the riboflavin/UVA collagen cross-linking increased significantly corneal stiffness, it decreased significantly its damping capability and deformability. This reduced damping ability might adversely interfere with corneal mechanical performance. (C) 2015 Elsevier Ltd. All rights reserved.