Radial distribution of white cells during blood flow in small tubes

Nobis, U.; Pries, Axel R.; Cokelet, Giles R.; Gaehtgens, P.

doi:10.1016/0026-2862(85)90020-2

Cited by 124 publications

(89 citation statements)

References 4 publications

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“…Some elements of the study reproduce and support previous findings on the shear dependence of adhesion of leukocytes and platelets from flowing blood (3,41,50) and of the tendency for red cell aggregation to increase margination and adhesion of leukocytes (18,32,34). However, by newly analyzing the effects of varying shear rate and stress independently (by manipulating flow rate and suspending phase viscosity), we have been able to show that cell size critically affects the attachment process by influencing velocity and, especially, force experienced by cells at the vessel wall.…”

Section: Discussionsupporting

confidence: 84%

Comparative rheology of the adhesion of platelets and leukocytes from flowing blood: why are platelets so small?

Watts

Barigou

Nash

2013

American Journal of Physiology-Heart and Circulatory Physiology

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Watts T, Barigou M, Nash GB. Comparative rheology of the adhesion of platelets and leukocytes from flowing blood: why are platelets so small? Am J Physiol Heart Circ Physiol 304: H1483-H1494, 2013. First published April 12, 2013 doi:10.1152/ajpheart.00881.2012.-We investigated rheological adaptation of leukocytes and platelets for their adhesive functions in inflammation and hemostasis, respectively. Adhesion and margination of leukocytes or platelets were quantified for blood perfused through capillaries coated with P-selectin or collagen, when flow rate, suspending phase viscosity, red cell aggregation, or rigidity was modified. Independent variation of shear rate and shear stress indicated that the ability of platelets to attach at higher levels than leukocytes was largely attributable to their smaller size, reducing their velocity before attachment, and, especially, drag after attachment. Increasing red cell aggregation increased the number of marginated and adhering leukocytes but inhibited platelet adhesion without effect on the number marginated. Increasing red cell rigidity tended to inhibit leukocyte adhesion but promote platelet adhesion. The effects on platelets may be explained by changes in the depth of the nearwall, red cell-depleted layer; broadening (or narrowing) this layer to greater (or less) than the platelet diameter would decrease (or increase) the normal force applied by red blood cells and make attachment less (or more) efficient. Thus different adhesive capabilities of leukocytes and platelets may arise from their differences in size, both directly because of influence on cell velocity and force experienced at the wall and indirectly through effects of size on margination in the bloodstream and interaction with the cell-free layer. In addition, red cell aggregation (of hitherto uncertain physiological significance) may be useful in promoting leukocyte adhesion in inflamed venules but inhibiting unwanted platelet deposition in veins. blood rheology; leukocyte adhesion; platelet adhesion; margination CIRCULATING LEUKOCYTES and platelets must adhere to the wall of blood vessels to carry out their protective functions in inflammation and hemostasis. Typically, leukocyte adhesion is restricted to postcapillary venules, where the wall shear rate (local velocity gradient) and wall shear stress (frictional drag on the wall) are low (ϳ100 s Ϫ1 and Ͻ1 Pa, respectively) (29, 38). Platelet adhesion is most important in the arterial circulation (with shear rate ϳ1,000 s Ϫ1 and stress Ͼ1 Pa) and, indeed, may be undesirable in slow-flowing veins at risk of thrombosis. Specialized, fast-acting receptors have evolved for the purpose of capture from flow: endothelial cell selectins bind sialylated, fucosylated glycoproteins on leukocytes, and von Willebrand factor (vWF) on collagen matrix binds the glycoprotein Ib complex on platelets (6, 54). The kinetics of these receptor pairs are quite similar (15), suggesting that attachment of the different cells in different regions must depend on their unequal ph...

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Section: Discussionsupporting

confidence: 84%

Comparative rheology of the adhesion of platelets and leukocytes from flowing blood: why are platelets so small?

Watts

Barigou

Nash

2013

American Journal of Physiology-Heart and Circulatory Physiology

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“…Similar increase of particle concentration near-wall has been reported for platelets and white blood cells distribution in capillary flow (Crowl and Fogelson, 2010;Nobis et al, 1985). Moreover, as the pressure drop increases, the -Ps mean concentration near the wall decreases, due to the increase of the cell freelayer with pressure drop (Albrecht et al, 1979).…”

Section: Radial Distribution Of -Pssupporting

confidence: 78%

Microfluidic interactions between red blood cells and drug carriers by image analysis techniques

D’Apolito

Taraballi

Minardi

et al. 2016

Medical Engineering & Physics

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Blood is a complex biological fluid composed of deformable cells and platelets suspended in plasma, a protein-rich liquid. The peculiar nature of blood needs to be considered when designing a drug delivery strategy based on systemically administered carriers. Here, we report on an in vitro fluid dynamic investigation of the influence of the microcapillary flow of red blood cells (RBCs) on micron sized carriers by high speed imaging methods. The experiments were carried out in a 50 m diameter glass capillary that mimicked the hydrodynamic conditions of human microcirculation. Spherical particles (-Ps), with sizes ranging between 0.5 and 3 m, were tested. Images of the flowing RBCs and -Ps were acquired by a highspeed/high-magnification microscopy. The transport and distribution of rigid particles in a suspension of RBCs under shear flow were followed for: i) the migration of RBCs towards the vessel centerline due to their deformability; ii) the cross-flow migration of -Ps towards the vessel wall due to their hydrodynamic interactions with RBCs; iii) the radial distribution of Ps in the presence of RBCs. This study suggests that the therapeutic efficacy of Ps could be ultimately affected by their interactions with the flowing RBCs in the vasculature.

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“…A number of studies showed that WBC margination increases significantly as a function of decreasing shear rate (19,42,(45)(46)(47). Similar trends have been reported for particles.…”

Section: Shear Ratesupporting

confidence: 65%

Particle Margination and Its Implications on Intravenous Anticancer Drug Delivery

et al. 2014

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Abstract. "Margination" refers to the movement of particles in flow toward the walls of a channel. The term was first coined in physiology for describing the behavior of white blood cells (WBCs) and platelets in blood flow. The margination of particles is desirable for anticancer drug delivery because it results in the close proximity of drug-carrying particles to the endothelium, where they can easily diffuse into cancerous tumors through the leaky vasculature. Understanding the fundamentals of margination may further lead to the rational design of particles and allow for more specific delivery of anticancer drugs into tumors, thereby increasing patient comfort during cancer treatment. This paper reviews existing theoretical and experimental studies that focus on understanding margination. Margination is a complex phenomenon that depends on the interplay between inertial, hydrodynamic, electrostatic, lift, van der Waals, and Brownian forces. Parameters that have been explored thus far include the particle size, shape, density, stiffness, shear rate, and the concentration and aggregation state of red blood cells (RBCs). Many studies suggested that there exists an optimal particle size for margination to occur, and that nonspherical particles tend to marginate better than spherical particles. There are, however, conflicting views on the effects of particle density, stiffness, shear rate, and RBCs. The limitations of using the adhesion of particles to the channel walls in order to quantify margination propensity are explained, and some outstanding questions for future research are highlighted.

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Radial distribution of white cells during blood flow in small tubes

Cited by 124 publications

References 4 publications

Comparative rheology of the adhesion of platelets and leukocytes from flowing blood: why are platelets so small?

Comparative rheology of the adhesion of platelets and leukocytes from flowing blood: why are platelets so small?

Microfluidic interactions between red blood cells and drug carriers by image analysis techniques

Particle Margination and Its Implications on Intravenous Anticancer Drug Delivery

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