Designing New Inhibitors to Prevent Enzyme Mediated Cartilage Degeneration for Preserving Cartilage Morphomechanics

Osteoarthritis (OA) is characterized by progressive degeneration of articular cartilage driven by the interplay of mechanical damage and enzyme-mediated matrix degradation. This dissertation investigates the morpho-biomechanical mechanisms underlying cartilage degeneration and evaluates a novel therapeutic strategy targeting protease activity under varying physiological conditions. First, an in vitro study was conducted to elucidate the combined effects of enzymatic degradation and mechanical damage on cartilage integrity. Results demonstrated that enzymatic activity significantly impairs collagen and proteoglycan content, leading to substantial reductions in compressive and dynamic mechanical properties. Notably, cartilage defects introduced prior to enzymatic exposure resulted in the most severe mechanical deterioration, highlighting a synergistic degradation mechanism. Building on these findings, the therapeutic potential of cartilage oligomeric matrix protein (COMP) in enhancing tissue inhibitor of metalloproteinases-3 (TIMP-3) was evaluated. The combined COMP–TIMP-3 strategy significantly improved mechanical properties, including instantaneous and dynamic moduli, and promoted preservation of extracellular matrix components. These results suggest that COMP enhances inhibitor efficacy by improving matrix stability and modulating protease activity. Finally, the influence of differential loading conditions, simulating variations in body weight and physical activity, was investigated. Increased mechanical loading was found to reduce therapeutic effectiveness, particularly in enzyme-compromised tissues. Distinct morpho-mechanical responses were observed under moderate and elevated loading conditions, emphasizing the importance of load-dependent therapeutic strategies. Overall, this work establishes a mechanistic link between enzymatic degradation, mechanical loading, and therapeutic response, providing a foundation for developing targeted, load-informed interventions for osteoarthritis management. The key contributions of this dissertation include: (i) establishing a mechanistic link between enzymatic degradation and mechanical damage, (ii) introducing a COMP-mediated enhancement of TIMP-3 as a novel therapeutic strategy, and (iii) demonstrating the critical role of physiological loading in modulating treatment efficacy. These findings provide a foundation for developing targeted, load-informed interventions for osteoarthritis management.