Comprehensive analysis of compositional interface fluctuations in planar lipid bilayer membranes

Area of Science:

• Biophysics
• Materials Science
• Soft Matter Physics

Background:

• Lipid bilayer membranes exhibit compositional fluctuations impacting their function.
• Understanding these dynamics is crucial for membrane biophysics and nanotechnology.
• Existing models often simplify transport and material properties.

Purpose of the Study:

• To comprehensively analyze line tension-driven compositional interface fluctuations in lipid bilayer membranes.
• To develop a generalized model that incorporates various physical effects.
• To provide a framework for understanding complex membrane dynamics.

Main Methods:

• Utilized the advective Cahn-Hilliard equation coupled with hydrodynamic equations.
• Derived sharp-interface limit equations from the phase-field formalism.
• Performed linear perturbation analysis to obtain the general dispersion relation ω(k).

Main Results:

• Developed a general dispersion relation incorporating advective/diffusive transport, membrane properties (viscous/viscoelastic), and solvent coupling.
• Showcased how previously studied scenarios emerge as limiting cases of the general result.
• Numerically evaluated the dispersion relation for three model membrane systems.

Conclusions:

• The generalized model provides a unified framework for studying membrane fluctuations.
• The model highlights the importance of considering solvent inertia and viscoelasticity for accurate predictions.
• This work advances the understanding of lipid bilayer dynamics and their implications.