Year: 2026
Type: preprint
Abstract: We consider extensions of the classical curvature-elasticity free energy for a fluid lipid membrane, explicitly treating the liquid crystal structure of the membrane, which results from the lipid molecules that are, on average, oriented normal to the surface. Locally varying liquid crystal order leads to local variations in bending rigidities and surface viscosity and thus influences the shape evolution. This provides a multiscale coupling between the local membrane mechanics on the level of the lipids and the mesoscopic length and time scales of biological functions. Numerical simulations in the one-constant approximation demonstrate the impact of local membrane mechanics on the emerging equilibrium shapes. These shapes not only depend on the specified conserved surface area and enclosed volume, as for the classical curvature-elasticity free energy, but also the elastic parameter and are characterized by a reduced liquid crystal order at highly curved regions. The modified shapes and their varying liquid crystal order, as function of curvature, provide experimentally testable properties. Exploring the dynamic evolution demonstrate a tight coupling of tangential flow, shape evolution and liquid crystalline order. We further point to model extensions towards lipid phase separation and asymmetric lipid bilayers and biological implications.
Source: arXiv (Cornell University)
Authors: Nitschke, Ingo, Porrmann, Maik, Voigt, Axel
Institution: Technische Universität Dresden
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Funder: Deutsche Forschungsgemeinschaft
Awards: G1438622245, G1575401848
OpenAlex ID: W7215088855