Joint lubrication

"Joint lubrication" is not a molecule, receptor, enzyme, transporter, or other discrete molecular target. Instead, it refers to the physiological process by which synovial joints are kept moist and slippery, allowing for smooth movement and minimizing friction between articulating surfaces. This process relies on several components within the synovial fluid—primarily hyaluronic acid, lubricin (also known as proteoglycan 4), surface-active phospholipids, and water—which together form various types of lubricant films over cartilage surfaces. The main mechanisms include boundary lubrication (thin molecular layers), fluid film/hydrodynamic lubrication (fluid layers separating surfaces), weeping/squeeze film/boosted/electrohydrodynamic effects depending on load conditions. Disruption or deficiency in these processes contributes significantly to diseases like osteoarthritis due to increased friction and subsequent cartilage damage. While therapies may aim at restoring aspects of this system—such as injecting hyaluronic acid or recombinant lubricin—the term "joint lubrication" itself does not denote a single druggable target but rather an emergent property resulting from multiple interacting molecules. Joint lubrication is best understood as a physiological function rather than a specific molecular entity suitable for direct pharmacological targeting.

Other names

Joint lubricationLubrication of synovial jointsArticular joint lubrication

Not applicable for "joint lubrication" itself; for related therapies, mechanisms include restoration of boundary or fluid film lubrication by supplementing hyaluronic acid or lubricin