ELECTROMECHANICAL PROPERTIES OF INTERVERTEBRAL DISC

腰痛是这个国家主要的社会经济问题。虽然腰痛的确切原因尚不清楚，但作为人类脊柱重要组成部分的椎间盘（IVD）的退行性改变已被认为是可能的主要病因。该项目的长期目标是：(1)更好地了解IVD的生物力学，(2)描述椎间盘衰竭的生物力学病因，(3)阐明腰痛的病理生理学，(4)开发新的微创椎间盘退变诊断工具。本试点研究的目的是为研究材料性能与组织组成和结构的关系开发新的技术和实验方案。具体目的是：(1)研究蛋白多糖（PG）含量和胶原基质密度对组织水化的影响，(2)研究正常和PG提取的IVD组织的电学性质，(3)研究正常和PG提取的IVD组织的动态压缩行为。本项目将进行三项实验研究。它们是：(1)固体基质含水量和真密度的测量，(2)电导率的测量，(3)正常和pg提取的动物IVD组织的动态压缩测试。实验数据也将用力学-电化学理论来解释材料性能与组织组成和结构的关系。这些研究将有助于了解组织水化的调节机制，椎间盘退变对材料特性和生物力学行为的影响，以及人类ivd椎间盘衰竭的生物力学病因。该结果将有助于未来理论模型的发展以及椎间盘退变的微创诊断工具。

Low-back pain is a major socio-economic concern in this country. Although the exact cause for low back pain is unclear, the degenerative changes of the intervertebral disc (IVD), a crucial component of the human spine, have been implicated as a possible primary etiologic factor. The long-term objectives of this project are: (1) to better understand the biomechanics of the IVD, (2) to delineate the biomechanical etiology of disc failure, (3) to elucidate the pathophysiology of low-back pain, and (4) to develop new, minimally invasive diagnostic tools for disc degeneration. The purpose of this pilot research is to develop new techniques and experimental protocols for the investigation of relations of material properties to tissue composition and structure. The specific aims are to (1) investigate effects of proteoglycan (PG) content and collagen matrix density on tissue hydration, (2) investigate electrical properties of normal and PG-extracted IVD tissues, and (3) investigate dynamic compressive behavior of normal and PG-extracted IVD tissues. Three experimental studies will be developed and performed in this project. They are: (1) measurements of water content and true density of solid matrix, (2) measurement of electrical conductivity, and (3) dynamic compression testing of normal and PG-extracted animal IVD tissues. The experimental data will also be analyzed using a mechano-electrochemical theory to elucidate the relations of material properties to tissue composition and structure. These studies will help to understand the mechanism for regulating tissue hydration, the effect of disc degeneration on material properties and biomechanical behavior, and the biomechanical etiology of disc failure in human IVDs. The results will be useful for the future development of theoretical modeling as well as minimally invasive diagnostic tools for disc degeneration.