Lubrication of articular cartilage

Lubrication of articular cartilage is not a molecule or receptor, and therefore cannot be treated as a therapeutic target in the traditional sense. It is a complex, multi-modal physiological process or physiological mechanism, not a discrete molecular entity suitable for drug targeting. The lubrication system relies on several distinct molecules and mechanisms working synergistically, including hyaluronic acid (HA), lubricin, proteoglycans (aggrecans), and phospholipids. These components contribute to lubrication mechanisms such as elastohydrodynamic, boundary, weeping, and boosted lubrication, which operate adaptively depending on loading conditions. For therapeutic intervention, focus should be on individual molecular targets involved in this process, such as hyaluronic acid, lubricin, or phospholipids, rather than the overarching process itself.