Combined depletion and electrostatic forces in polymer-induced membrane adhesion: A theoretical model

摘要: We develop a semi-quantitative analytical theory to describe adhesion between two identical planar charged surfaces embedded in polymer-containing electrolyte solution. Polymer chains are uncharged and differ from the solvent by their lower dielectric permittivity. The solution mimics physiological fluids: It contains 0.1 M of monovalent ions small number divalent cations that form tight bonds with headgroups lipids. components have heterogeneous spatial distributions. model was derived self-consistently combining: (a) Poisson-Boltzmann like equation for charge densities, (b) continuum mean-field polymer profile, (c) solvation energy forcing toward polymer-poor regions, (d) surface interactions polymers electrolytes. validated via extensive coarse-grained Molecular Dynamics (MD) simulations. results confirm our reveal interesting details not detected theory. At high c...