In vitro analysis of blood flow in a microvascular network with realistic geometry

Kodama, Yuya; Aoki, Hiroyoshi; Yamagata, Yutaka; Tsubota, Kazuo

doi:10.1016/j.jbiomech.2019.03.022

Cited by 12 publications

(4 citation statements)

References 21 publications

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“…Different cellular-scale mechanisms were identified that could affect the local RBC distribution: (I) skewness of the hematocrit profile in the parent branch; (II) RBC lingering at branching points; 4 (III) local self-regulation due to cell-cell and cell-vasculature interactions; and (IV) flow balancing due to transient capillary obstructions. 5 In contrast to computational models, in vitro studies to investigate the local RBC partitioning for complex and anatomically plausible microvascular networks 15,28,34,54 are scarce. In particular, there is a lack of experimental research with channel sizes comparable to the RBC diameter ( 10 μm), which can probably be attributed to technical challenges of microfabrication.…”

Section: Introductionmentioning

confidence: 99%

In vitro investigations of red blood cell phase separation in a complex microchannel network

2020

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Microvascular networks feature a complex topology with multiple bifurcating vessels. Nonuniform partitioning ( phase separation) of red blood cells (RBCs) occurs at diverging bifurcations, leading to a heterogeneous RBC distribution that ultimately affects the oxygen delivery to living tissues. Our understanding of the mechanisms governing RBC heterogeneity is still limited, especially in large networks where the RBC dynamics can be nonintuitive. In this study, our quantitative data for phase separation were obtained in a complex in vitro network with symmetric bifurcations and 176 microchannels. Our experiments showed that the hematocrit is heterogeneously distributed and confirmed the classical result that the branch with a higher blood fraction received an even higher RBC fraction (classical partitioning). An inversion of this classical phase separation (reverse partitioning) was observed in the case of a skewed hematocrit profile in the parent vessels of bifurcations. In agreement with a recent computational study [P. Balogh and P. Bagchi, Phys. Fluids 30,051902 (2018)], a correlation between the RBC reverse partitioning and the skewness of the hematocrit profile due to sequential converging and diverging bifurcations was reported. A flow threshold below which no RBCs enter a branch was identified. These results highlight the importance of considering the RBC flow history and the local RBC distribution to correctly describe the RBC phase separation in complex networks.

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Section: Introductionmentioning

confidence: 99%

In vitro investigations of red blood cell phase separation in a complex microchannel network

2020

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“…Currently, in vitro experiments on a scale %10 mm addressing network effects are rare because of the complexity of the fabrication procedure. Nonetheless, there has been significant progress in mimicking realistic microvascular networks in vitro and addressing partitioning of RBCs in subsequent bifurcations (31) and dilating vessels (32,33). Albeit most results from FIGURE 5 Probability density functions of scaled void durations for all branches if only lingering events are taken into account.…”

Section: Figurementioning

confidence: 99%

Lingering Dynamics in Microvascular Blood Flow

Kihm

Quint

Laschke

et al. 2021

Biophysical Journal

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The microvascular networks in the body of vertebrates consist of the smallest vessels such as arterioles, capillaries, and venules. The flow of red blood cells (RBCs) through these networks ensures the gas exchange in as well as the transport of nutrients to the tissues. Any alterations in this blood flow may have severe implications on the health state. Because the vessels in these networks obey dimensions similar to the diameter of RBCs, dynamic effects on the cellular scale play a key role. The steady progression in the numerical modeling of RBCs, even in complex networks, has led to novel findings in the field of hemodynamics, especially concerning the impact and the dynamics of lingering events when a cell meets a branch of the network. However, these results are yet to be matched by a detailed analysis of the lingering experiments in vivo. To quantify this lingering effect in in vivo experiments, this study analyzes branching vessels in the microvasculature of Syrian golden hamsters via intravital microscopy and the use of an implanted dorsal skinfold chamber. It also presents a detailed analysis of these lingering effects of cells at the apex of bifurcating vessels, affecting the temporal distribution of plasmatic zones of blood flow in the branches and even causing a partial blockage in severe cases.

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“…Stauber et al [ 13 ] investigated the flow behavior of RBCs in a microfluidic platform that mimicked alveolar capillaries. Kodama et al [ 14 ] investigated the flow rates and hematocrit values in each segment using microchannels that reflected the microvascular networks in rabbit ovaries. Mantegazza et al [ 15 , 16 ] examined the uneven partitioning characteristics of RBCs using microflow channels with complex honeycomb networks.…”

Section: Introductionmentioning

confidence: 99%

Red Blood Cell Partitioning Using a Microfluidic Channel with Ladder Structure

et al. 2023

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This study investigated the partitioning characteristics of red blood cells (RBCs) within capillaries, with a specific focus on ladder structures observed near the end of the capillaries. In vitro experiments were conducted using microfluidic channels with a ladder structure model comprising six bifurcating channels that exhibited an anti-parallel flow configuration. The effects of various factors, such as the parent channel width, distance between branches, and hematocrit, on RBC partitioning in bifurcating channels were evaluated. A decrease in the parent channel width resulted in an increase in the heterogeneity in the hematocrit distribution and a bias in the fractional RBC flux. Additionally, variations in the distance between branches affected the RBC distribution, with smaller distances resulting in greater heterogeneity. The bias of the RBC distribution in the microchannel cross section had a major effect on the RBC partitioning characteristics. The influence of hematocrit variations on the RBC distribution was also investigated, with lower hematocrit values leading to a more pronounced bias in the RBC distribution. Overall, this study provides valuable insights into RBC distribution characteristics in capillary networks, contributing to our understanding of the physiological mechanisms of RBC phase separation in the microcirculatory system. These findings have implications for predicting oxygen heterogeneity in tissues and could aid in the study of diseases associated with impaired microcirculation.

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In vitro analysis of blood flow in a microvascular network with realistic geometry

Cited by 12 publications

References 21 publications

In vitro investigations of red blood cell phase separation in a complex microchannel network

In vitro investigations of red blood cell phase separation in a complex microchannel network

Lingering Dynamics in Microvascular Blood Flow

Red Blood Cell Partitioning Using a Microfluidic Channel with Ladder Structure

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