Lipobeads: a hydrogel anchored lipid vesicle system.

A new vesicle system is described that combines complementary properties of liposomes and polymeric beads. 'Lipobeads' consist of a lipid bilayer shell anchored on the surface of a hydrogel polymer cores which acts like a cytoskeleton. Anchoring is provided by fatty acids covalently attached to the surface of the hydrogel. These hydrophobic chains drive spontaneous assembly of a lipid bilayer shell around the modified hydrogel bead when exposed to a suspension of liposomes. The bilayer is stable and acts as a permeability barrier to compound loaded by prior absorption into the polymer core. Lipid mobility in the shell is similar to that found in other unanchored lipid bilayers. The system has potential application in drug delivery and for functional reconstitution of membrane proteins.