| Articular cartilage is a connective tissue which facilitates joint motion by providing a wear-resistant, load bearing, lubricated surface on the ends of long bones. These properties can be compromised when cartilage is damaged, necessitating clinical intervention, since articular cartilage exhibits little intrinsic capacity for healing. Clinical treatments often result in the formation of a cartilage-cartilage interface following implantation of a tissue graft or tissue substitute. Integration of the implanted material with the surrounding host cartilage is necessary for successful treatment. However, a lack of integration at cartilage-cartilage interfaces is a recurring problem in treatment of cartilage damage. In vitro studies can help elucidate mechanisms by which integrative cartilage repair can be improved.; This dissertation research investigates the role of collagen metabolism and transport in an in vitro model of integrative cartilage repair. A brief description of the structure, function, and composition of articular cartilage is followed by discussions of cartilage development, clinical and experimental studies of integrative cartilage repair, and mass transport studies involving articular cartilage. Using an in vitro model system, integrative repair of bovine cartilage explants was found to be dependent on the deposition of newly formed collagen at a tissue-tissue interface, and the development of adhesive strength was related to the amount of collagen deposited. Further, there appeared to be a developmental effect, since samples from different stages of bovine maturation (fetal, newborn calf, and skeletally-mature adult) exhibited distinctly different levels of integration. Finally, a mathematical model was constructed to describe the processes of collagen synthesis, transport, deposition, and degradation that together determine the location of newly formed cartilage matrix molecules during integrative repair. |
