Development of a Biocompatible, 3D-Printable, Hydrogel Scaffold with Antioxidant and Tunable Mechanical Properties for Articular Cartilage Tissue Engineering and Inflammation Reduction

The work presented in this dissertation focused on developing a biocompatible, 3D-printable with high fidelity, and mechanically tunable hydrogel-based scaffold for articular cartilage (AC) tissue engineering (TE) applications. The scaffold also has potential to be functionalized with antioxidant nutraceuticals for inflammation reduction in osteoarthritis (OA) environments. This dissertation addressed three specific aims. These were: 1) Assessing the effects of four nutraceuticals (catechin hydrate (C), gallic acid (G), alpha tocopherol (Alpha), and ascorbic acid (AA)) on inflammation reduction and extracellular matrix (ECM) production ability of OA chondrocytes, 2) developing a biocompatible, 3D-printable, and mechanically tunable tri-component hydrogel-based scaffolds composed of sodium alginate (SA), gelatin (GEL), and gum Arabic (GA) referred to as SA-GEL-GA that mimic native AC compressive modulus for AC TE applications, and 3) evaluating the cytocompatibility of the developed scaffolds with bovine articular chondrocytes (bAChs), and evaluate ECM and pericellular matrix (PCM) production by isolating intact chondrons grown in SA-GEL-GA. In summary, in this dissertation we have successfully developed a biocompatible, 3D-printable, mechanically tunable hydrogel-base composite scaffold that can be tuned to provide compressive moduli range of 50 – 250 kPa. This scaffold supports proliferation of bAChs while maintaining their native circular phenotype as well as hyaline-like ECM and PCM deposition in vitro. All of which makes it a great potential candidate for use in matrix-assisted chondrocyte transplantation (MACT) therapy. Finally, this scaffold could also potentially be functionalized with catechin hydrate to give it antioxidant properties to help reduce inflammation in OA environments.