Mechanistic Investigation of Articular Cartilage Development Representative of Diseased, Healthy, and Induced Inflammation States

The three studies presented in this dissertation focused on a mechanistic evaluation of Articular Cartilage (AC) tissue's formation in vitro in healthy, diseased and inflamed states. In the first study, the effects of four nutraceuticals (Alpha-tocopherol (Alpha), Gallic-Acid (G), Ascorbic-Acid (AA), and Catechin-Hydrate(C)) on OA human chondrocytes divided into two groups based on sex were explored. Cells responded to nutraceuticals via extracellular matrix (ECM) formation and inflammation reduction in a sex-dependent manner with chondrocytes isolated from females and males responding well to G and Alpha respectively. The second study was a mechanistic assessment of temporal changes in chondrocytes' phenotypes and function in an in vitro culture over 21 days as they form ECM. We utilized atomic force microscopy (AFM) to detect the nanomechanical and morphological properties of chondrocytes as well as traditional cell biology techniques to quantify ECM formation. Our results indicated that cells become more rigid, less adherent and less rough as they progress in culture. The third study aimed at quantifying the effects of induced inflammation via interleukin-1-beta (IL1β) and lipopolysaccharides (LPS) on chondrocytes' mechanobiology and morphological responses. We found that IL1β and LPS modulate chondrocytes' responses differently via morphological changes, cytoskeleton rearrangements and reduction in adhesion energy and cellular roughness. The results presented in this dissertation will ultimately support the knowledge and development of enhanced regenerative medicine strategies towards a remedy for OA.