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Saffman-Delbrück and beyond: A pointlike approach
Quentin Goutaland1, Jean-Baptiste Fournier2
1Laboratoire "Matière et Systèmes Complexes" (MSC), UMR 7057 CNRS, Université de Paris, 75205, Paris Cedex 13, France.
The European Physical Journal. E, Soft Matter
|December 14, 2019
Summary
This study provides an analytical approximation for Saffman-Delbrück
Area of Science:
- Biophysics
- Fluid Dynamics
- Materials Science
Background:
- The Saffman-Delbrück (SD) law describes the mobility of inclusions within biological membranes.
- Accurate modeling of membrane-inclusion dynamics is crucial for understanding cellular processes.
- Existing models may not fully account for membrane complexity, such as bilayer structure and intermonolayer friction.
Purpose of the Study:
- To develop an improved analytical approximation for the Saffman-Delbrück law.
- To investigate the influence of membrane bilayer properties and intermonolayer friction on inclusion mobility.
- To analyze the effects of local spontaneous curvature induced by inclusions.
Main Methods:
- Analytical approximation derived from the velocity field of a pointlike force in a 2D fluid.
- Incorporation of a small wavelength cutoff (particle radius 'a') for approximation.
- Consistent coupling of quasi-planar 2D membrane flow with 3D solvent flow.
Main Results:
- Generalizations of the SD law accounting for bilayer membranes and intermonolayer friction ('b').
- For flat bilayers, SD law holds with modified viscosity, independent of 'b' above a practical threshold.
- For inclusions in one monolayer, mobility is influenced by 'b' below a critical value, potentially doubling mobility.
Conclusions:
- The proposed method offers a robust analytical approximation for Saffman-Delbrück mobility.
- Membrane bilayer nature and intermonolayer friction significantly impact inclusion dynamics.
- The study provides a theoretical basis for the contribution of membrane deformation to inclusion friction.
Keywords:
Living systems: Biological Matter
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