Jay, Gregory D., et al. The Role of Lubricin in the Mechanical Behavior of Synovial Fluid. PNAS 104(15):6194-6199, 2007.
Synovial fluid is a semidilute hyaluronate (HA) polymer solution, the rheology of which depends on HA-protein interactions, and lubricin is a HA-binding protein found in synovial fluid and at cartilage surfaces, where it contributes to boundary lubrication under load. Individuals with genetic deficiency of lubricin develop precocious joint failure. The role of lubricin in synovial fluid rheology is not known. This study examines the role of lubricin in the mechanical behavior of synovial fluid. Findings indicate that lubricin provides synovial fluid with an ability to dissipate strain energy induced by mammalian locomotion, which is a chondroprotective feature that is distinct from boundary lubrication.