The effect of deactivated phospholipids on joints lubrication: Osteoarthritis and lubricating properties

PLs bilayers coating the major synovial joints such as knees and hips as the lubricant are responsible for the lubrication of articular cartilage. Lamellar-repulsive effect has been considered as a lubrication mechanism but it is likely that lubricin and hyaluronan with PLs participate in the lubrication process. The molecules of lubricin and hyaluronan adsorbed by PLs have a supportive role and provide the efficient lubrication of synovial joints via the hydration mechanism (~ 80% water content). Lipid profiles of injured and healthy knees’ synovial fluids show significant differences. The phospholipid content in synovial fluid (SF) during joint inflammation, osteoarthritis is significantly higher (2 to 3 times) above the normal concentration of PL, and has a poor boundary-lubricating ability because of deactivated PL molecules. Deactivated PL molecule has no ability to form bilayers, lamellar phases, and liposomes.