Red cells' dynamic morphologies govern blood shear thinning under microcirculatory flow conditions.
Blood viscosity decreases with shear stress, a property essential for an efficient perfusion of the vascular tree. Shear thinning is intimately related to the dynamics and mutual interactions of RBCs, the major component of blood. Because of the lack of knowledge about the behavior of RBCs under physiological conditions, the link between RBC dynamics and blood rheology remains unsettled. We performed experiments and simulations in microcirculatory flow conditions of viscosity, shear rates, and volume fractions, and our study reveals rich RBC dynamics that govern shear thinning. In contrast to the current paradigm, which assumes that RBCs align steadily around the flow direction while their membranes and cytoplasm circulate, we show that RBCs successively tumble, roll, deform into rolling stomatocytes, and, finally, adopt highly deformed polylobed shapes for increasing shear stresses, even for semidilute volume fractions of the microcirculation. Our results suggest that any pathological change in plasma composition, RBC cytosol viscosity, or membrane mechanical properties will affect the onset of these morphological transitions and should play a central role in pathological blood rheology and flow behavior.
Centre de Biochimie Structurale, CNRS UMR 5048, INSERM UMR 1054, University of Montpellier, 34090 Montpellier, France.
Luca
L
Lanotte
Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Juelich, Germany.
Johannes
J
Mauer
Institut Montpelliérain Alexander Grothendieck, UMR 5149 051, University of Montpellier, 34095 Montpellier, France.
Simon
S
Mendez
Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Juelich, Germany.
Dmitry A
DA
Fedosov
Laboratoire Charles Coulomb, CNRS UMR 5587, University of Montpellier, 34095 Montpellier, France.
Jean-Marc
JM
Fromental
Centre de Biochimie Structurale, CNRS UMR 5048, INSERM UMR 1054, University of Montpellier, 34090 Montpellier, France.
Viviana
V
Claveria
Institut Montpelliérain Alexander Grothendieck, UMR 5149 051, University of Montpellier, 34095 Montpellier, France.
Franck
F
Nicoud
Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Juelich, Germany.
Gerhard
0000-0002-8904-0986
G
Gompper
Centre de Biochimie Structurale, CNRS UMR 5048, INSERM UMR 1054, University of Montpellier, 34090 Montpellier, France; Manouk.Abkarian@univ-montp2.fr.
Manouk
M
Abkarian
D001783:Blood Flow Velocity / Q000502:physiology; D004548:Elasticity / Q000502:physiology; D004907:Erythrocyte Deformability / Q000502:physiology; D004912:Erythrocytes / Q000166:cytology / Q000502:physiology*; D006403:Hematologic Tests; D006801:Humans; D008833:Microcirculation / Q000502:physiology; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D008853:Microscopy / Q000379:methods; D010949:Plasma; D012212:Rheology / Q000379:methods*; D013314:Stress, Mechanical; D014783:Viscosity
blood rheology; blood simulation; cell dynamics; red blood cell