Quantification of depletion-induced adhesion of Red Blood Cells

TL;DR

This study measures how dextran induces adhesion between red blood cells using atomic force microscopy, revealing how dextran concentration and molecular weight affect cell interaction energy, aligning with depletion effect models.

Contribution

It provides the first direct single-cell force measurements of RBC adhesion induced by dextran, enhancing understanding of rouleaux formation mechanisms.

Findings

Adhesion energy varies with dextran concentration and molecular weight.

Results support the depletion effect model for RBC aggregation.

Single-cell force spectroscopy effectively quantifies RBC adhesion.

Abstract

Red blood cells (RBC) are known to form aggregates in the forms of rouleaux due to the presence of plasma proteins under physiological conditions. Rouleaux formation can be also induced in vitro by the addition of macromolecules to the RBC solution. Current data on the adhesion strength between red blood cells in their natural discocyte shapes mostly rely on indirect measurements like flow chamber experiments, but on the single cell level data is lacking. Here we present measurements on the dextran induced aggregation of red blood cells by use of atomic force microscopy based single cell force spectroscopy (SCFS). The effects of dextran concentration and molecular weight on the interaction energy of adhering RBCs was determined. The results are in good agreement with a model based on the depletion effect and former experimental studies.