Elucidation of Adaptive Multimode Lubrication Mechanism in Natural Synovial Joints from Hierarchic and Microscopic Viewpoints

本研究的目的是从层次和微观的角度阐明天然滑膜关节的自适应多模态润滑机制。为阐明天然滑膜关节的自适应多模态润滑机理，进行了系统的研究。仿真器对膝关节模型液膜形成的实验评估和数值分析表明，弹性流体动力润滑在行走过程中的重要作用。采用摆锤法对猪肩关节进行摩擦试验，明确了透明质酸浓度对高、低负荷条件下摩擦行为的影响，涉及去除吸附膜或添加磷脂或蛋白质。由磷脂、蛋白质和糖蛋白组成的吸附膜在去除吸附膜后摩擦力增加，从而清楚地表明了吸附膜对边界的润滑作用。磷脂脂质体和γ -球蛋白的加入对降低摩擦有较好的效果。对关节软骨滑动副和玻璃板上形成的Langmuir-Blodgett膜的往复试验表明，磷脂和蛋白质混合膜优于磷脂膜。体内实验证实了混合吸附膜的保护作用。应用原子力显微镜（AFM）观察不同摩擦水平下关节软骨表面在摩擦过程中的变化。研究了不同摩擦水平下的力-距离曲线。研究结果表明，吸附膜和凝胶膜的润滑作用随着磨损的加剧而发生变化。将聚乙烯醇（PVA）水凝胶样品作为人工软骨与天然关节软骨的摩擦学性能进行了比较，以阐明两种材料的差异。通过锥形/平板粘度计对培养的单层软骨细胞进行连续剪切试验，发现剪切刺激可诱导白细胞介素6 （IL-6）显著升高，拟进行三维数值分析，研究剪切刺激对关节软骨软骨细胞的影响。少

The object of this research is to elucidate the adaptive multimode lubrication mechanism in natural synovial joints from the hierarchic and microscopic viewpoints.The systematic investigation was performed to clarify the adaptive multimode lubrication mechanism in natural synovial joints. Experimental evaluation of fluid film formation in knee joint model in simulator and numerical analysis showed the important role of elastohydrodynamic lubrication during walking. In friction tests of pig shoulder joints by pendulum method, the influence of hyaluronate concentration on frictional behavior under high and low load conditions was clarified in related to removal of adsorbed films or addition of phospholipid or proteins. The boundary lubrication by adsorbed film composed of phospholipids, proteins and glycoproteins was clearly shown by an increase in friction after removal of adsorbed film. Addition of liposome of phospholipid liposome and gamma-globulin was effective in lowering of fricti … More on. Reciprocating tests of sliding pair of articular cartilage and Langmuir-Blodgett film formed on glass plate indicated the superiority of mixed film of phospholipid and protein to phospholipid film. The protecteive effect by mixed adsorbed film was confirmed in in-vivo tests. The atomic force microscopy (AFM) was applied to observe the changes in articular cartilage surfaces at different friction levels during rubbing process. The corresponding force-distance curves at several friction levels were examined. These results indicated that lubricating roles of adsorbed film and gel film changes with progressive wear process. The tribological property of polyvinyl-alcohol (PVA) hydrogel specimen as artificial cartilage was compared with that of natural articular cartilage to clarify the difference between both materials. The three-dimensional numerical analysis was planned to examine the influence of shearing stimulation on chondrocyte in articular cartilage which was found in continuous shearing test to monolayer of cultured chondrocyte in cone/plate viscometer inducing the remarkable increase in interleukin 6 (IL-6). Less