There are common features, in the mechanisms that control lubrication and spreading at biological interfaces. Phospholipids are increasingly recognised as playing an important part, as boundary layer lubricants, and in the role of spreading. Their solubility and interfacial behaviour is facilitated by the formation of protein-lipid complexes, in which hydrophobic association is the environmental driver for structural stability. These structures are found in interfacial biological fluids, such as synovial fluid, tears and lung surfactant, where they contribute to interfacial stability and lubrication properties.
To mimic these native systems, we have examined structural variations within those synthetic macromolecules, that can exhibit analogous secondary structures, to that of native apoproteins, and we have sought hydrophobically associating synthetic polymers, which interact with phospholipids; to form a range of self-assembled structures, that mimic the function of native protein-lipid complexes.
We have developed synthetic biolubricants that can operate at bio-surfaces, to ensure that they remain lubricious, wettable and impart a low surface activity. We refer to these structures as "Astosomes". This novel platform technology addresses deficiencies in lubrication. They combine effectively with hyaluronic acid, in a way that offers potential advantage, towards the development of novel synthetic biological lubricants.
Variations in molecular weight and monomer structure together with the nature and degree of hydrophobic substitution enable optimisation of structures for a range of applications. These include extraction and stabilisation of membrane proteins, the attachment of phospholipids to the surface of medical devices (e.g. contact lenses) and the solubilisation of hydrophobic drugs for transport and delivery.