Effect of Hydration on Healthy Intervertebral Disk Mechanical Stiffness
Effect of Hydration on Healthy Intervertebral Disk Mechanical Stiffness
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DOI：
10.1115/1.4031416
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发表时间：
2015-10-01
影响因子：
1.7
通讯作者：
O'Connell, Grace D.
中科院分区：
文献类型：
--
作者：
Bezci, Semih E.;Nandy, Aditya;O'Connell, Grace D.
椎间盘具有极好的吸水膨胀能力，这被认为主要是由于高蛋白聚糖组成。损伤、老化、退化和昼夜负荷都可以通过含水量和组织水合作用的显著降低来观察。本研究的目的是评估水合作用，通过渗透负荷，对健康椎间盘的组织肿胀和压缩刚度的影响。膨胀后髓核（NP）和纤维环（AF）外植体的湿重为50%或更大，表明在所有渗透负荷条件（0.015 M-3.0 M磷酸盐缓冲盐水（PBS））下具有显著的吸水能力。根据膨胀比计算的估计NP残留应变约为AF残留应变的1.5倍。压缩刚度随着高渗载荷的增加而增加，这被认为是由于高渗载荷引起的材料压实和非线性力学行为。重要的是，这项研究表明，残余应变和材料特性在很大程度上取决于渗透负荷。这项研究的结果支持的概念，从渗透负荷的溶胀性能将是重要的，准确地描述椎间盘力学退化和损伤的影响。此外，组织肿胀将是开发旨在恢复健康椎间盘机械行为的生物修复策略的重要考虑因素。
The intervertebral disk has an excellent swelling capacity to absorb water, which is thought to be largely due to the high proteoglycan composition. Injury, aging, degeneration, and diurnal loading are all noted by a significant decrease in water content and tissue hydration. The objective of this study was to evaluate the effect of hydration, through osmotic loading, on tissue swelling and compressive stiffness of healthy intervertebral disks. The wet weight of nucleus pulposus (NP) and annulus fibrosus (AF) explants following swelling was 50% or greater, demonstrating significant ability to absorb water under all osmotic loading conditions (0.015M-3.0M phosphate buffered saline (PBS)). Estimated NP residual strains, calculated from the swelling ratio, were approximately 1.5 x greater than AF residual strains. Compressive stiffness increased with hyperosmotic loading, which is thought to be due to material compaction from osmotic-loading and the nonlinear mechanical behavior. Importantly, this study demonstrated that residual strains and material properties are greatly dependent on osmotic loading. The findings of this study support the notion that swelling properties from osmotic loading will be important for accurately describing the effect of degeneration and injury on disk mechanics. Furthermore, the tissue swelling will be an important consideration for developing biological repair strategies aimed at restoring mechanical behavior toward a healthy disk.