membranesthin

Membranesthin is a term used to describe a reduction in the thickness of a membrane, especially a lipid bilayer, relative to its typical thickness of about 4 to 5 nanometers for a single bilayer. The concept is used in both biology and materials science to describe how membranes can become thinner under certain conditions, affecting their physical properties and function. Membranesthin can refer to biological membranes in cells as well as to synthetic membranes such as lipid vesicles, polymer films, or supported lipid bilayers used in experiments.

Causes include changes in lipid composition (such as increased unsaturation or shorter acyl chains), temperature changes that shift lipid phase from gel to liquid-crystalline, mechanical tension, and interactions with proteins, peptides, or solvents that disrupt tail packing. In many systems, thinning accompanies a transition to a more disordered state, reducing hydrophobic thickness and increasing area per lipid.

Measurement and observation: thickness can be assessed by X-ray or neutron reflectivity, small-angle scattering, cryo-electron microscopy, atomic force microscopy, or inferential methods based on fluorescence probes. In living cells, thinning can occur transiently at sites of fusion, pore formation, or remodeling, and in synthetic membranes thinning can influence permeability and stability.

Implications: thinning modulates barrier properties, diffusion of water and solutes, and the activity of membrane proteins. It is considered in studies of drug delivery, membrane fusion, antimicrobial action, and the design of thin-film membranes for filtration or sensing.