Dr. Grayson DuRaine, a postdoc in Prof. Athanasiou’s lab, has received a two-year Arthritis Foundation Postdoctoral Fellowship to support his project, “Combinatorial stimuli in cartilage tissue engineering.” In arthritis, cartilage failure results in the abrasive grinding of bone to bone, leading to inflammation, pain, and severe reductions in mobility, independence, and general quality of life. In order to replace or regenerate articular cartilage, tissue engineering has thus far been focused toward generating neocartilages with high compressive and tensile properties. However, the native tissue features a low-friction bearing surface to ensure movement of the joints, and this lubrication factor has not been thoroughly addressed in cartilage repair. To produce successful tissue engineered articular cartilage for the eventual treatment of arthritis, both mechanical properties and lubrication must be considered.
The key lubricant present in the synovial fluid and superficial zone of articular cartilage is superficial zone protein (SZP), and it helps to maintain cartilage structure during locomotion. Lack of SZP results in degenerative changes in the tissue, and in osteoarthritis animal models, decreased levels of SZP have been observed. SZP is responsive to mechanical stimulus, with sliding shear resulting in an increase in SZP expression in native bovine cartilage. To this end, his project seeks to engineer lubricating properties into tissue engineered articular cartilage constructs using sliding shear as a mechanical stimulus.