Elucidation of Adaptive Multimode Lubrication, Deterioration and Restoration in Natural Synovial Joints

本研究的目的是阐明自然滑膜关节的适应性多模式润滑机制及其与退化和修复的关系，对自然滑膜关节的适应性多模式润滑进行了系统的研究。膝关节模型在模拟器上的流体膜形成的实验评估和数值分析表明，弹性流体动力润滑在步行过程中的重要作用。关节滑膜和关节软骨的冲击试验表明存在蛋白质保护膜，特别是试验后的γ-球蛋白和冲击诱导的软骨电现象。在摆锤法猪肩关节摩擦试验中，阐明了透明质酸浓度对高、低载荷下关节摩擦性能的影响与蛋白质的添加效应有关。由磷脂和蛋白质组成的吸附膜的边界润滑，清楚地显示了由吸附膜去除后的摩擦增加。磷脂和蛋白质脂质体的加入对降低摩擦力有明显效果。关节软骨滑动副与玻璃板上形成的Langmuir-Biodgett膜往复运动实验表明磷脂和蛋白质混合膜优于磷脂膜，锥板粘度计对培养软骨细胞单层连续剪切实验表明IL-6显著增加。这表明，不良润滑引起的剪切刺激在骨关节炎的恶化和恢复中起着重要作用。

The object of this research is to elucidate the adaptive multimode lubrication mechanism in natural synovial joints and to clarify its relation to degradation and restoration.The systematic investigation was performed to elucidate the adaptive multimode lubrication 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. Impact tests of synovia and articular cartilage exhibited the existence of protecting film of proteins, particularly gamma-globulin after testing and impact-induced electrical phenomena of cartilage. 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 effect of added proteins. The boundary lubrication by adsorbed film composed of phospholipids and proteins was clearly shown by an increase in friction after removal of adsorbed film. Addition of liposome of phospholipid and protein was effective in lowering of friction. Reciprocating tests of sliding pair of articular cartilage and Langmuir-Biodgett film formed on glass plate indicated the superiority of mixed film of phospholipid and protein to phospholipid film.The continuous shearing to monolayr of cultured chondrocyte in cone/plate viscometer showed the remarkable increase in interleukin 6 (IL-6). This suggests that the shearing stimulation due to inferior lubrication plays an important role in deterioration and restoration in osteoarthritis.