Liquid-Ordered/Liquid-Crystalline Phase Separation at a Lipid Bilayer Suspended over Microwells

The localisation of liquid-ordered (L-o) and liquid-crystalline (La) phase domains on a silicon substrate with a microwell array is investigated. Although the phase separation of the Lo and La phases on both a giant unilamellar vesicle (GUV) and a supported membrane remains stable for a long time, the lateral diffusion of lipids across each domain boundary occurs quickly. Since the phase separation and domain arrangement are governed by the stiffness and lateral tension of the lipid membrane, the phase separation is rearranged on a rnicropatterned substrate. Similar phase separation of the Lo and La phases is observed at a lipid membrane suspended over a microwell. However, the La phase is preferred at a suspended membrane, and saturated lipids and cholesterol are excluded toward the supporting membrane on the periphery. Since the Lo domain area is reduced by anisotropic diffusion through the boundary between the suspended and supported membranes, a very slow reduction rate with a La phase domain is observed at a membrane suspended over a microwell, which is membrane. linear functional relation is observed. Finally, a localized surrounded by an Lo phase supported membrane.