Correlation Analysis between PG Content and Frictional Characteristics of Agarose-Chondrocyte Model Cultured under Repeated Compressive Loading

Abstract

With the aging of the population worldwide, musculoskeletal diseases in the elderly are becoming more important, and osteoarthritis caused by cartilage wear and tear is a problem because it leads to a reduced quality of life. Since cartilage does not have blood vessels and has poor self-repair capabilities, research on artificial joints, artificial cartilage, and regenerated cartilage as alternatives has been vigorously conducted. One approach is to elucidate the lubrication mechanism of articular cartilage. Hydration of biopolymers on the cartilage surface contributes to low friction. One of these biopolymers is proteoglycan (hereafter referred to as PG). In this study, we evaluated the lubricating effect of PG on cartilage tissue scale. An agarose-chondrocyte model was prepared by seeding chondrocytes in agarose gel, cultured under compressive loading, and the frictional behavior was evaluated using a rheometer. The amount of PG synthesized by the chondrocytes and accumulated in the model and the dynamic viscoelasticity of the model was then measured by colorimetric analysis and dynamic viscoelasticity test. As a result, we were able to quantitatively evaluate the lubricating effect of PG on the various parameters that constitute frictional behavior and changes in dynamic viscoelasticity.