Nanostructures of Phospholipids on Articular Cartilage Surface and their Functions

Phospholipids bilayers fulfill an important role in natural joint lamellar-repulsive lubrication mechanism. Low friction between surfaces coated with negatively charged the phospholipid headgroup (–PO4-) as being due to a hydration layer. Wettability of the cartilage surface depends on the number of PLs that act as a lubricant. The cartilage can be classified as a group of intelligent material, which in the wet state has a contact angle of ~0º, and the air-dry state has a contact angle of ~104º.