Red blood cell clustering in Poiseuille microcapillary flow

Abstract

Red blood cell (RBC) flow-induced clustering, which is a physiopathologically-relevant process in microcirculation, is usually attributed to slower RBCs acting to create a train of trailing cells. Here, based on the first systematic investigation of collective RBC flow behavior in microcapillaries in vitro by high-speed video microscopy and 2D boundary integral numerical simulations, we show that RBC clustering is elicited by hydrodynamical interactions only, even if the effect of polydispersity is taken into account. Furthermore, lower applied pressure drops and longer residence times favor larger RBC clusters. The insight on the mechanism of RBC clustering provided by this work can be applied to further our understanding of RBC aggregability, which is a key parameter implicated in clotting and thrombus formation

Biomechanical properties of red blood cells in health and disease towards microfluidics

“…The cell can be osmotically swelled before the experiments, in order to obtain a spherical shape, that makes small deformations easier to detect 67 Microfluidic devices, coupled with automated image analysis, are suitable for point-of-care applications, 77 allowing to test a large number of cells by using microcirculation-mimicking patterns, 78 transparent substrata such as polydimethylsiloxane and glass, and video microscopy. Examples include visualizations of cell deformation as a function of pressure drop, in which the classical parachute-like shape observed in vivo was observed in in vitro experiments as well, 66,[79][80][81][82][83][84] estimations of cell membrane viscoelastic properties such as RBC shear elastic modulus and surface viscosity by using diverging channels, 65 measurements of the RBC time recovery constant in start-up experiments, 35 cell characterization by electric impedance microflow cytometry, 85 and single-cell microchamber array (SiCMA) technology 86,87 (Figures 3(D1) and 3(D2)). The latter applies a dielectrophoretic force to deform RBCs and used image analysis to analyse RBCs shape changes, allowing the evaluation the deformability of single RBCs in terms of Elongation Index %, defined as (x À y)/(x þ y) Â 100, where x and y are RBC major and minor axes, respectively.…”

Red blood cell aggregate flux in a bifurcating microchannel

“…The viscoelastic properties of blood have been examined in early [4][5][6] as well as more recent studies [7,8], illustrating the weaklyattractive suspension nature of blood. The fact that the flow characteristics may play a role on the aggregation of RBCs has been observed in the studies of Tomaiuolo et al [9] and Claveria et al [10], where RBC clustering in microconfined Poiseuille flow is observed independent of aggregative forces. The cluster length was observed to be pressure drop dependent and the formation of larger clusters was favoured by longer residence times in the shear conditions tested [9].…”

“…The fact that the flow characteristics may play a role on the aggregation of RBCs has been observed in the studies of Tomaiuolo et al [9] and Claveria et al [10], where RBC clustering in microconfined Poiseuille flow is observed independent of aggregative forces. The cluster length was observed to be pressure drop dependent and the formation of larger clusters was favoured by longer residence times in the shear conditions tested [9]. In the study of Clavería et al [10], red blood cell suspensions in physiological buffer solutions (PBS) and in Dextran solutions at different concentrations were used to mimic healthy and pathological levels of fibrinogen in capillary configurations.…”

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

“…A home-made imageprocessing routine enabled the detection of individual cells. We define two cells to be a part of a cluster if their center-tocenter distance is smaller than or equal to 1.5 times the length of one single cell as proposed by Tomaiuolo et al 3 . However, this value is heuristically selected and not based on theoretical considerations.…”

“…1). The physical origin of this cluster formation can be either the long-ranged hydrodynamic interaction [2][3][4][5][6] or a short-range aggregation mechanism, which is caused by the plasma macromolecules 7 . The latter relates to the so-called rouleaux formation 8 .…”