Cluster of red blood cells in microcapillary flow: hydrodynamic versus macromolecule induced interaction

TL;DR

This study investigates how red blood cell clusters form and stabilize in microcapillaries, highlighting the roles of hydrodynamic interactions and plasma protein-induced adhesion, with insights from experiments and simulations.

Contribution

It demonstrates the interplay between hydrodynamics and adhesion forces in RBC clustering, supported by experiments and 2D numerical simulations.

Findings

Clusters form due to hydrodynamics and plasma proteins.

Shear stresses can disrupt or stabilize clusters.

Simulations show transition between adhesive and non-adhesive states.

Abstract

We present experiments on RBCs that flow through microcapillaries under physiological conditions. We show that the RBC clusters form as a subtle imbrication between hydrodynamics interaction and adhesion forces because of plasma proteins. Clusters form along the capillaries and macromolecule-induced adhesion contribute to their stability. However, at high yet physiological flow velocities, shear stresses overcome part of the adhesion forces, and cluster stabilization due to hydrodynamics becomes stronger. For the case of pure hydrodynamic interaction, cell-to-cell distances have a pronounced bimodal distribution. Our 2D-numerical simulations on vesicles captures the transition between adhesive and non-adhesive clusters at different flow velocities.