Biolubrication synergy: Hyaluronan – Phospholipid interactions at interfaces

The manner in which nature has solved lubrication issues has fascinated scientists for centuries, in particular when considering that lubrication is achieved in aqueous media. The most outstanding system in this respect is likely the synovial joint, where close to frictionless motion is realized under different loads and shear rates. This review article focuses on two components present in the synovial area, hyaluronan and phospholipids. We recapitulate what has been learned about their interactions at interfaces from recent experiments, with focus on results obtained using reflectivity techniques at large scale facilities. In parallel, modelling experiments have been carried out and from these efforts new detailed knowledge about how hyaluronan and phospholipids interact has been gained. In this review we combine findings from modelling and experiments to gain deeper insight. Finally, we summarize what has been learned of the lubrication performance of mixtures of phospholipids and hyaluronan. [Display omitted] •Modelling highlights the importance of hydrogen bonds, hydrophobic interactions and ion bridges for hyaluronan at phospholipid bilayers.•Experiments demonstrate the importance of hyaluronan molecular weight and the presence of divalent ions.•Phospholipid-hyaluronan mixtures can generate very low friction forces up to pressures exceeding those in synovial joints.