Slow flow of passive neutrophils and sequestered nucleus into micropipette

Kaleridis, Vassilios E; Athanassiou, G.; Deligianni, Despina; Missirlis, Yannis F.

doi:10.3233/ch-2010-1326

Cited by 5 publications

(2 citation statements)

References 33 publications

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“…They performed deformation tests on the neutrophil and its nucleus using micropipette under low aspiration pressure. They observed that the nucleus plays a significant role in the mechanical and rheological behavior of the neutrophils, especially while passing through openings much smaller than their size (18). Using video observation simultaneously illuminated for fluorescence and phase contrast microscopy, Campbell et al (4) analyzed the nuclear movements of moving neutrophils in vitro.…”

Section: Passive Deformationmentioning

confidence: 99%

Why are Neutrophils Polymorphonuclear?

Veda

2011

Eur J Inflamm

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Most cells in the human body have a spherical or ovoid nucleus. The mature human neutrophil, unlike most other cells exhibits a distinctly non-spherical nucleus, which is segmented into three to five lobes. The possible mechanisms underlying this segmented nuclear shape have been explored. The structure of the nuclear envelope, composition of lamins and lamin-B receptor seems to have an important role in shaping the nucleus. Being the first line of defense, neutrophils migrate rapidly to the site of infection and destroy the invading pathogen. This requires negotiation through narrow capillaries, transmigration across the vessel wall and passage through tight tissue spaces. Segmented shape confers increased nuclear flexibility, thereby easing the migration ofneutrophils through narrow channels. The segmented shape ofthe nucleus may also playa role in intranuclear chromatin organization and gene expression. The unique shape of the neutrophil nucleus seems to be an adaptation to facilitate its function.

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Section: Passive Deformationmentioning

confidence: 99%

Why are Neutrophils Polymorphonuclear?

Veda

2011

Eur J Inflamm

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“…Hence newer methods were devised in an attempt to study large number of RBC under flow-like conditions. In contrast to RBC, micropipette studies are still commonly used to examine leukocytes; though these approaches tend not to be focused on rheological deformability [22,35,[48][49][50][51][52][53].…”

Section: Micropipette Aspirationmentioning

confidence: 99%

Assessing the Vascular Deformability of Erythrocytes and Leukocytes: From Micropipettes to Microfluidics

Scott¹,

Matthews²,

Ma³

2020

Current and Future Aspects of Nanomedicine

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Among the most crucial rheological characteristics of blood cells within the vasculature is their ability to undergo the shape change (i.e., deform). The significance of cellular deformability is readily apparent based solely on the disparate mean size of human erythrocytes (~8 μm) and leukocytes (10-25 μm) compared to the minimum luminal size of capillaries (4-5 μm) and splenic interendothelial clefts (0.5-1.0 μm) they must transit. Changes in the deformability of either cell will result in their premature mechanical clearance as well as an enhanced possibility of intravascular lysis. In this chapter, we will demonstrate how microfluidic devices can be used to examine the vascular deformability of erythrocytes and agranular leukocytes. Moreover, we will compare microfluidic assays with previous studies utilizing micropipettes, ektacytometry and micropore cell transit times. As will be discussed, microfluidics-based devices offer a low-cost, high throughput alternative to these previous, and now rather ancient, technologies.Current and Future Aspects of Nanomedicine 2 and prone to mechanical interaction with the endothelial cells lining the blood vessels. WBC also have adhesion molecules on their membrane and, if appropriate signals (e.g., inflammation) are present, they actively roll on the endothelial cells prior to attachment and extravasation (Figure 1A,B). Moreover, the viscosity of blood is also variable and is a function of, primarily, red blood cell (RBC) number and flow rate. At high RBC counts and high flow rates, blood is highly viscous while at low RBC counts and low flow rates (capillaries), blood viscosity is greatly reduced. Moreover, as shown in Figure 1C, the rheological stress is further exacerbated by the biomechanical stresses induced by the extreme disparity in the size of RBC (~8 μm) and WBC (10-25 μm) to the minimum diameter of the vascular Assessing the Vascular Deformability of Erythrocytes and Leukocytes: From Micropipettes… DOI: http://dx.doi.org/10.5772/intechopen.90131 Conflict of interestThe University of British Columbia and HM have pending patent applications relating to the described microfluidic devices.

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Measurement and Analysis of Lymphocyte Deformation in Microchannel Contraction Flows Using a Compound Drop Model

Tatsumi

Haizumi

Sugimoto

et al. 2015

Flow Turbulence Combust

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To understand the physical properties of lymphocytes and to develop a numerical model that can predict their motion and deformation in flows, a three-dimensional numerical simulation of lymphocytes flowing through the contraction region of a microchannel was performed using a compound drop model. The present model considers shear-thinning effects on the cytoplasm and the nucleus by modeling a second droplet inside the primary cell. The time-dependent characteristics of the deformation index (DI) of the lymphocyte, and the effects of the flow rate and the nucleus position on the DI are discussed and compared with the measurement. The results demonstrated that the conventional drop model, in which Newtonian fluid properties are applied to the cytoplasm, cannot correctly predict the deformation of the cell in the contraction region, where the nonlinear effects become important, whereas the compound drop model was consistent with experimental measurements of lymphocyte deformation. The size and position of the nucleus were found to influence the shape of the lymphocyte as measured by a change in the deformation rate of the leading and trailing sides of the lymphocyte. Further, a simplified model of lymphocyte deformation in the steady elongational flow was employed to determine the apparent viscosity, including the shear-thinning effects, of the lymphocyte.

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Slow flow of passive neutrophils and sequestered nucleus into micropipette

Cited by 5 publications

References 33 publications

Why are Neutrophils Polymorphonuclear?

Why are Neutrophils Polymorphonuclear?

Assessing the Vascular Deformability of Erythrocytes and Leukocytes: From Micropipettes to Microfluidics

Measurement and Analysis of Lymphocyte Deformation in Microchannel Contraction Flows Using a Compound Drop Model

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