Optimal formation of uniform-phase supported lipid bilayers from phospholipid–monoglyceride bicellar mixtures

Abstract

Supported lipid bilayers (SLBs) spanning hydrophilic surfaces are industrially attractive biomimetic coatings that mimic critical aspects of lipid membrane interfaces and are increasingly used in applications spanning medicine, biotechnology, and environmental science. The use of adsorbing bicelle lipid nanostructures composed of long- and short-chain phospholipid mixtures is an effective self-assembly driven process for streamlined SLB fabrication. However, existing studies use synthetic short-chain phospholipids as a necessary bicelle component and such materials are not practical for industrial applications. Herein, we investigated optimal conditions to fabricate SLBs from bicelles containing an industrially useful monoglyceride called monocaprin (MC) in place of short-chain phospholipids. The ratio of long-chain phospholipid to MC along with total lipid concentration were systematically tested. Quartz crystal microbalance-dissipation (QCM-D) and time-lapse fluorescence microscopy experiments were performed to characterize bicelle adsorption onto silicon dioxide surfaces, and fluorescence recovery after photobleaching (FRAP) measurements were conducted to evaluate lateral lipid diffusion within the fabricated lipid adlayers. Depending on bicelle parameters, high-quality SLB formation with uniform phase properties was achieved and optimal ranges are described to ensure target performance outcomes without phase separation. Together, our findings demonstrate that MC-containing bicelles are useful tools to form high-quality SLBs suitable for surface coating and biosensing applications.