title: Clusters of red blood cells in microcapillary flow: hydrodynamic versus macromolecule induced interaction.
abstract: We present experiments on RBCs that flow through micro-capillaries under physiological conditions. The strong flow-shape coupling of these deformable objects leads to a rich variety of cluster formation. We show that the RBC clusters form as a subtle imbrication between hydrodynamic interactions and adhesion forces because of plasma proteins, mimicked by the polymer dextran. Clusters form along the capillaries and macromolecule-induced adhesion contributes 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 capture the transition between adhesive and non-adhesive clusters at different flow velocities.
authors.affiliation: Experimental Physics, Saarland University, 66123, Saarbrücken, Germany. c.wagner@mx.uni-saarland.de and Centre de Biochimie Structurale, CNRS UMR5048, INSERM U1054, Université de Montpellier, 29 rue de Navacelles, 34090 Montpellier, France.
authors.forename: Viviana
authors.initials: V
authors.lastname: Clavería
authors.affiliation: Experimental Physics, Saarland University, 66123, Saarbrücken, Germany. c.wagner@mx.uni-saarland.de and Université Grenoble Alpes, LIPHY, F-38000 Grenoble, France and CNRS, LIPHY, F-38000 Grenoble, France and LMPHE, URAC 12, Faculté des Sciences, Université Mohammed V-Agdal, Rabat, Morocco.
authors.forename: Othmane
authors.initials: O
authors.lastname: Aouane
authors.affiliation: Université Grenoble Alpes, LIPHY, F-38000 Grenoble, France and CNRS, LIPHY, F-38000 Grenoble, France.
authors.forename: Marine
authors.initials: M
authors.lastname: Thiébaud
authors.affiliation: Centre de Biochimie Structurale, CNRS UMR5048, INSERM U1054, Université de Montpellier, 29 rue de Navacelles, 34090 Montpellier, France.
authors.forename: Manouk
authors.initials: M
authors.lastname: Abkarian
authors.affiliation: Université Grenoble Alpes, LIPHY, F-38000 Grenoble, France and CNRS, LIPHY, F-38000 Grenoble, France.
authors.forename: Gwennou
authors.initials: G
authors.lastname: Coupier
authors.affiliation: Université Grenoble Alpes, LIPHY, F-38000 Grenoble, France and CNRS, LIPHY, F-38000 Grenoble, France.
authors.forename: Chaouqi
authors.initials: C
authors.lastname: Misbah
authors.affiliation: Experimental Physics, Saarland University, 66123, Saarbrücken, Germany. c.wagner@mx.uni-saarland.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: John
authors.affiliation: Experimental Physics, Saarland University, 66123, Saarbrücken, Germany. c.wagner@mx.uni-saarland.de.
authors.forename: Christian
authors.initials: C
authors.lastname: Wagner
mesh_terms: D004912:Erythrocytes / Q000166:cytology*; D006801:Humans; D057446:Hydrodynamics; D013314:Stress, Mechanical