A Gaussian model for the membrane of red blood cells with cytoskeletal defects

TL;DR

This paper introduces a Gaussian model for red blood cell membranes with cytoskeletal defects, analyzing fluctuation spectra, crossover behaviors, and defect detection methods to advance non-invasive diagnostics.

Contribution

It presents a novel Gaussian network model capturing membrane fluctuations and defect signatures, including analytical and numerical analysis of cytoskeletal bond deficiencies.

Findings

Identifies non-monotonic fluctuation features and crossover regimes.

Shows non-diagonal correlations reveal cytoskeletal defects.

Provides a basis for non-invasive defect spectroscopy.

Abstract

We study a Gaussian model of the membrane of red blood cells: a "phantom" triangular network of springs attached at its vertices to a fluid bilayer with curvature elasticity and tension. We calculate its fluctuation spectrum and we discuss the different regimes and non-monotonic features, including the precise crossover at the mesh size between the already known limits with two different tensions and the renormalisation of the bending rigidity at low wavevectors. We also show that the non-diagonal correlations reveal, in "dark field", the cytoskeletal defects. As a first step toward a non-invasive defect spectroscopy, the specific case of lacking bonds is studied numerically and analytically.