Hyaline cartilage of the diarthroidal joints undergoes significant loading and repetitive cycling during regular daily activity. Due to high loading and trauma from injury, cartilage lesions can form and may lead to osteoarthritis (OA). The prevalence of these cartilage lesions and the limited repair capabilities of cartilage has lead to extensive research in development of new materials and methods of repairing cartilage lesions. Our lab focuses on the use of biomaterials and cells to for surgical interventions to repair cartilage lesions. The objective of this project is to develop fibrous hydrogels for tissue engineering of cartilage lesions. Extensive research has been performed using hydrogels and electrospun fibrous scaffolds independently as materials for cartilage tissue engineering. However, these materials have not been studied in conjugation with each other. By incorporating electrospun meshes into hydrogels we will be able to mimic the proteoglycan gel and collagen fibers of native cartilage. We hypothesize that by incorporating fibrous meshes, made from chondroitin sulfate (CS), into our current hydrogel of interest, poly(ethylene glycol) (PEG), we win achieve enhanced cartilage-like tissue formation using chondrocytes and chondrogenically differentiating mesenchymal stem cells. We are proposing to use chondroitin sulfate as the base material for the electrospun nanofibers because previous research in our lab has shown enhanced chondrogenesis of mesenchymal stem cells in the presence of CS in the form of hydrogels and fiber-hydrogels compared to PEG hydrogels. In addition to enhancing the cartilage tissue formed we believe that these fibers will also lend significant mechanical stability to the scaffold during the process of tissue repair and integration. To achieve this objective we will first electrospin chondroitin sulfate-based nanofibers and evaluate the cartilage-like tissue formation. This will be performed by 1.) seeding the cells directly onto the electrospun fibers and 2.) incorporated the fiber meshes into PEG hydrogels followed by subsequent analysis of the tissue formed. In vivo translation of the developed fibrous hydrogels will be validated using subcultaneous implantation followed by implantations into condyle defects in rats. Relevance: Approximately 65% of those over the age of 60 years old are affected by osteoarthritis (OA) resulting in pain and possible immobility. The current treatments for OA are limited by inadequate tissue repair and typically result in the need for further treatments. Therefore, it is necessary to design new surgical interventions to enhance the current treatments with the use of biomaterials.
