Atomic force microscope investigation of the boundary-lubricant layer in articular cartilage
Atomic force microscope investigation of the boundary-lubricant layer in articular cartilage
复制标题
DOI：
10.1016/j.joca.2010.03.012
复制
发表时间：
2010-07-01
影响因子：
7
通讯作者：
Reddi, A. H.
中科院分区：
文献类型：
--
作者：
Chan, S. M. T.;Neu, C. P.;Reddi, A. H.
目的：通过胰蛋白酶、透明质酸酶和磷脂酶-C（PLC）表面处理系统酶消化关节软骨，确定表面带蛋白（SZP）、透明质酸（HA）和表面活性磷脂（SAPL）在关节软骨边界润滑中的作用。还测量了关节面的表面粗糙度、附着力和刚度，以确定边界润滑状态下的摩擦机制。组织学和透射电子显微镜被用来可视化的表面变化的治疗组，表现出显着的摩擦变化后酶消化.Results：一个显着增加的摩擦系数的承载和非承载区域的联合后，观察蛋白酶水解。用胰蛋白酶、透明质酸酶或PLC处理不影响表面粗糙度。而胰蛋白酶处理则显著降低了粘附性。结果表明，关节软骨表面的蛋白质成分是主要的边界润滑剂，SZP是一个主要的候选者。目前的纳米级变形过程可能是塑料和/或粘弹性的性质，这表明犁是占主导地位的摩擦mechanism.Conclusions：这项研究的结果表明，SZP起着内在的和关键的作用，在关节软骨表面的边界润滑，而HA和SAPL的摩擦学行为的影响是边缘的。(C)2010年国际骨关节炎研究学会。由爱思唯尔有限公司出版。保留所有权利。
Objective: To determine the roles of superficial zone protein (SZP), hyaluronan (HA), and surface-active phospholipids (SAPL) in boundary lubrication of articular cartilage through systematic enzyme digestion using trypsin, hyaluronidase, and phospolipase-C (PLC) surface treatments.Methods: The friction coefficient of articular cartilage surfaces was measured with an atomic force microscope (AFM) before and after enzyme digestion. Surface roughness, adhesion, and stiffness of the articular surface were also measured to determine the mechanism of friction in the boundary lubrication regime. Histology and transmission electron microscopy were used to visualize the surface changes of treatment groups that showed significant friction changes after enzyme digestion.Results: A significant increase in the friction coefficient of both load-bearing and non load-bearing regions of the joint was observed after proteolysis by trypsin. Treatment with trypsin, hyaluronidase, or PLC did not affect the surface roughness. However, trypsin treatment decreased the adhesion significantly. Results indicate that the protein component at the articular cartilage surface is the main boundary lubricant, with SZP being a primary candidate. The prevailing nanoscale deformation processes are likely plastic and/or viscoelastic in nature, suggesting that plowing is the dominant friction mechanism.Conclusions: The findings of this study indicate that SZP plays an intrinsic and critical role in boundary lubrication at the articular surface of cartilage, whereas the effects of HA and SAPL on the tribological behavior are marginal. (C) 2010 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.