Researcher(s)
- Jenna Averill, Biomedical Engineering, University of Delaware
Faculty Mentor(s)
- Charles Dhong, Material Science Engineering/Biomedical Engineering, University of Delaware
Abstract
Osteoarthritis (OA) leads to progressive breakdown of the articular cartilage, causing abnormal joint loading and reduced mobility among patients. The articular cartilage is comprised of an extracellular matrix (ECM) consisting of a collagen network, with embedded glycosaminoglycans (GAGs). The sulfated GAGs build a negative charge distribution within the ECM and drive an osmotic pressure within the tissue. Our lab has been investigating the usage of polystyrene sulfonate (PSS) to diffuse into the ECM and replenish the negative charge to OA cartilage. My research focuses on determining the biocompatibility and mechanical effectiveness of PSS as a future injectable OA therapeutic. We first dissect cartilage explants from adult bovine metacarpal phalangeal (ankle) joints. To test the biocompatibility range of PSS, we are currently using a lactate dehydrogenase (LDH) assay as well as live/dead staining to find optimal concentrations of PSS. We have found that PSS at varying concentrations is biocompatible and less cytotoxic than chondroitin sulfate. Next, to confirm that PSS is improving mechanical properties, we are currently studying the stress relaxation and creep profiles of bovine osteochondral plugs to determine if PSS can improve the equilibrium modulus and permeability of OA cartilage. We expect that the equilibrium modulus increases and the permeability decreases, as a result of restoring the lost negative charge via PSS. This work will lead to the usage of PSS as an injectable therapeutic drug to improve the mechanical properties of damaged tissue caused by OA.