Development of cartilaginous tissue in chondrocyte-agarose construct cultured under traction loading

In this study, chondrocytes isolated from bovine cartilage tissue were seeded in agarose gel and resultant chondrocyte- agarose constructs, a well-established experimental model to examine the effect of mechanical loadings on the chondrocyte metabolism, were cultured with a traction loading on the construct surface to examine its effect on the regeneration of the cartilaginous tissue by chondrocytes. Customdesigned mechanical loading equipment was developed to apply the traction loading on the upper surface of constructs being cultured in the CO₂ incubator. After 2 or 3 weeks culture, quantities of glycosaminoglycan (GAG) molecules that proteoglycan, and type II collagen were determined, and immunofluorescent staining of keratin sulfate, a type of GAG, and type II collagen was performed to verify the chondrocyte biosynthesis of extra cellular matrix (ECM) and characterize the structure of elaborated cartilaginous tissue by confocal laser scanning microscopy (CLSM). Results indicated that the traction loading enhance ECM biosynthesis in the surface region of constructs and collagen rich layer covered with GAG rich superficial layer was formed in the articulation surface. Results of quantification for ECM molecules indicated that the production of type II collagen and GAG was more significant outside the slide track compared with inside the slide track.