Elucidation of Adaptive Multimode Lubrication Mechanism, Self-Organization and Restoration Mechanism in Natural Synovial Joints

本研究的目的是从层次和微观的角度阐明自然滑膜关节的适应性多模式润滑机制与自组织和修复的关系，以防止骨关节炎的进展，改善再生软骨的功能。利用原子力显微镜(AFM)观察不同摩擦水平的骨关节炎膝关节软骨和猪软骨在不同摩擦水平下关节软骨表面的形态变化。检查相应的力-距离曲线以评估力学性能。采用激光共聚焦扫描显微镜(CLSM)观察关节软骨细胞染色后的荧光图像，观察压缩状态下关节软骨的局部应变。用激光共聚焦显微镜观察关节软骨细胞的形态和分布。基于两相有限元Me-…的三维数值分析进一步观察压缩刺激对关节软骨细胞的影响。由蛋白多糖组成的润滑凝胶膜似乎保护了大块软骨，即使在严重摩擦的情况下也保持低摩擦。凝胶膜中的蛋白多糖是由软骨细胞生产的。观察软骨细胞周围应力应变的变化，因为对软骨细胞的适当刺激可以影响蛋白多糖的产生。另一种低摩擦的保护机制是在摩擦表面形成吸附膜。在含有球状血清蛋白的透明质酸溶液中，考察了聚乙烯醇(PVA)水凝胶作为人工软骨和软骨模型的摩擦学性能。选择合适的白蛋白和γ球蛋白组成，可获得较低的磨损量和摩擦力。通过对蛋白质荧光图像的原位观察，清楚地证实了吸附行为的差异。全内反射荧光显微镜(TIRFM)被成功地应用于观察蛋白质的吸附行为。较少

The object of this research is to elucidate the adaptive multimode lubrication mechanism in natural synovial joints in relation to the self-organization and restoration from the hierarchic and microscopic viewpoints, to prevent the progress of osteoarthritis and to improve the function in regenerated cartilage.The atomic force microscopy (AFM) was applied to observe the morphological changes in articular cartilage surfaces removed from knee joints with osteoarthritis and porcine cartilage at different friction levels during rubbing experiments. The corresponding force-distance curves were examined to estimate the mechanical properties. The confocal laser scanning microscopy (CLSM) was used to estimate the local strain of articular cartilage under compression by observing the fluorescent images of stained chondrocytes. The morphology and distribution of chondrocytes in articular cartilage were investigated by CLSM. Three-dimensional numerical analysis based on biphasic finite element me … More thod was conducted to examine the influence of compressive stimulation on chondrocyte in articular cartilage. Lubricating gel film composed of proteoglycan appears to protect the bulk cartilage and maintain low friction even under severe rubbing. The proteoglycan in gel film is supplied through production by chondrocyte. The changes in stress-strain around chondrocyte was examined, because appropriate stimulation to chondrocyte can give an influence on the production of proteoglycan. Another protective mechanism with low friction is given by adsorbed film formation on the rubbing surface. The tribological property of polyvinyl-alcohol (PVA) hydrogel specimen as artificial cartilage or a model of cartilage was examined in hyaluronate solution containing globular serum proteins. The appropriate constituents composed of albumin and γ-globulin resulted in lower wear and lower friction. The difference in adsorptional behavior was clearly confirmed with in situ observation of fluorescent images of proteins. The total internal reflection fluorescence microscopy (TIRFM) was successfully applied to observe adsorptional behavior of proteins. Less