membranesupported

Membrane-supported, or supported membrane, describes a system in which a biological or synthetic lipid membrane is attached to a solid substrate, creating a planar, two-dimensional environment suitable for controlled experiments. Such membranes are used to study membrane processes under flat, accessible conditions while retaining key properties of bilayers, such as lateral mobility of lipids and embedded proteins.

Construction methods commonly used to create membrane-supported systems include the formation of supported lipid bilayers (SLBs) on hydrophilic surfaces such as glass, silica, mica, or gold by vesicle fusion, where small unilamellar vesicles adsorb, rupture, and spread into a bilayer. Alternative methods include Langmuir-Blodgett and Langmuir-Schaefer deposition. To improve stability and preserve membrane dynamics, polymer cushions or tethers can separate the bilayer from the substrate. Tethered or polymer-cushioned membranes attach via biotin-streptavidin linkages or covalent anchors, reducing substrate friction and preserving protein function.

Properties of membrane-supported systems include retained lateral mobility of lipids, with diffusion behavior influenced by membrane composition and any cushion layer. The distal leaflet is typically solvent-accessible, enabling reconstitution of membrane proteins and interactions with solutes. However, proximity to the substrate can alter hydration, slow diffusion near the surface, or distort protein function.

Applications span biophysical studies of membrane proteins, ion channels, and receptors; biosensing and surface plasmon resonance assays; high-resolution fluorescence microscopy and single-molecule techniques; and areas of drug discovery and nanobiotechnology. Limitations include potential perturbation of bilayer chemistry by the support, unwanted interactions with proteins, electrostatic effects, and variable long-term stability depending on surface chemistry and buffer conditions.