Lipid Mixtures in Monolayer and BLM

The relationship between spreading monolayers at the water/air interface and planar lipid bilayers (BLM) of 1-monooleoyl-glycerol MON), 1-monostearoyl-glycerol (MOS), galactocerebrosides (GAL), and MOS/MON, GAL/MON mixtures has been studied. Spreading isotherms were obtained and the monomolecular surface phases of these substances were examined and described through state equations. Molecular orientations of MON, MOS, and GAL hydrocarbon chains were discussed according to the surface phase rule. The two-dimensional miscibility of MOS/MON and GAL/MON mixtures was also studied. The MON, MOS/MON, and GAL/MON planar bilayers were obtained and their electrical capacitance and resistance were measured. Some relations between miscibility in monolayer and BLM formation were established: 1) substances giving liquid films at the w/a interface produce stable BLMs; 2) components miscible in monolayers at the w/a interface give stable planar bilayers.