Model for probing membrane-cortex adhesion by micropipette aspiration and fluctuation spectroscopy

TL;DR

This paper introduces a coupled model for membrane-cortex adhesion that predicts critical detachment pressure and adhesion energy, incorporating active stresses and fluctuations, enabling quantitative analysis of cortical activity via micropipette experiments.

Contribution

The model uniquely integrates membrane mechanics, hydrodynamics, ligand kinetics, and cortical activity, providing a comprehensive framework for analyzing membrane-cortex interactions.

Findings

Critical pressure for membrane detachment depends on active stresses.

Adhesion energy varies significantly with cortical activity.

Fluctuation spectroscopy combined with micropipette aspiration reveals stability details.

Abstract

We propose a model for membrane-cortex adhesion which couples membrane deformations, hydrodynamics and kinetics of membrane-cortex ligands. In its simplest form, the model gives explicit predictions for the critical pressure for membrane detachment and for the value of adhesion energy. We show that these quantities exhibit a significant dependence on the active acto-myosin stresses. The model provides a simple framework to access quantitative information on cortical activity by means of micropipette experiments. We also extend the model to incorporate fluctuations and show that detailed information on the stability of membrane-cortex coupling can be obtained by a combination of micropipette aspiration and fluctuation spectroscopy measurements.