In Silico Investigation of the RBC Velocity Fluctuations in Ex Vivo Capillaries

A properly functioning capillary microcirculation is essential for sufficient oxygen and nutrient delivery to the central nervous system. The physical mechanisms governing the transport of red blood cells (RBCs) inside the narrow and irregularly shaped capillary lumen are complex, but understanding...

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Main Authors: Eren Çolak, Özgür Ekici, Şefik Evren Erdener
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Applied Sciences
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Online Access:https://www.mdpi.com/2076-3417/15/14/7796
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author Eren Çolak
Özgür Ekici
Şefik Evren Erdener
author_facet Eren Çolak
Özgür Ekici
Şefik Evren Erdener
author_sort Eren Çolak
collection DOAJ
description A properly functioning capillary microcirculation is essential for sufficient oxygen and nutrient delivery to the central nervous system. The physical mechanisms governing the transport of red blood cells (RBCs) inside the narrow and irregularly shaped capillary lumen are complex, but understanding them is essential for identifying the root causes of neurological disorders like cerebral ischemia, Alzheimer’s disease, and other neurodegenerative conditions such as concussion and cognitive dysfunction in systemic inflammatory conditions. In this work, we conducted numerical simulations of three-dimensional capillary models, which were acquired ex vivo from a mouse retina, to characterize RBC transport. We show how the spatiotemporal velocity of the RBCs deviates in realistic capillaries and equivalent cylindrical tubes, as well as how this profile is affected by hematocrit and red cell distribution width (RDW). Our results show a previously unprecedented level of RBC velocity fluctuations in capillaries that depends on the geometric features of different confinement regions and a capillary circularity index <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>(</mo><msub><mi>I</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub><mo>)</mo></mrow></semantics></math></inline-formula> that represents luminal irregularity. This velocity fluctuation is aggravated by high hematocrit conditions, without any further effect on RDW. These results can provide a better understanding of the underlying mechanisms of pathologically high capillary transit time heterogeneity that results in microcirculatory dysfunction.
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spelling doaj-art-ad3b5cba4aee46a4a29686e7915c7c882025-08-20T03:35:36ZengMDPI AGApplied Sciences2076-34172025-07-011514779610.3390/app15147796In Silico Investigation of the RBC Velocity Fluctuations in Ex Vivo CapillariesEren Çolak0Özgür Ekici1Şefik Evren Erdener2Graduate School of Science and Engineering, Hacettepe University, Ankara 06800, TurkeyMechanical Engineering Department, Hacettepe University, Ankara 06800, TurkeyInstitute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara 06100, TurkeyA properly functioning capillary microcirculation is essential for sufficient oxygen and nutrient delivery to the central nervous system. The physical mechanisms governing the transport of red blood cells (RBCs) inside the narrow and irregularly shaped capillary lumen are complex, but understanding them is essential for identifying the root causes of neurological disorders like cerebral ischemia, Alzheimer’s disease, and other neurodegenerative conditions such as concussion and cognitive dysfunction in systemic inflammatory conditions. In this work, we conducted numerical simulations of three-dimensional capillary models, which were acquired ex vivo from a mouse retina, to characterize RBC transport. We show how the spatiotemporal velocity of the RBCs deviates in realistic capillaries and equivalent cylindrical tubes, as well as how this profile is affected by hematocrit and red cell distribution width (RDW). Our results show a previously unprecedented level of RBC velocity fluctuations in capillaries that depends on the geometric features of different confinement regions and a capillary circularity index <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>(</mo><msub><mi>I</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub><mo>)</mo></mrow></semantics></math></inline-formula> that represents luminal irregularity. This velocity fluctuation is aggravated by high hematocrit conditions, without any further effect on RDW. These results can provide a better understanding of the underlying mechanisms of pathologically high capillary transit time heterogeneity that results in microcirculatory dysfunction.https://www.mdpi.com/2076-3417/15/14/7796LBMIBMDEMFEMRBCcapillary
spellingShingle Eren Çolak
Özgür Ekici
Şefik Evren Erdener
In Silico Investigation of the RBC Velocity Fluctuations in Ex Vivo Capillaries
Applied Sciences
LBM
IBM
DEM
FEM
RBC
capillary
title In Silico Investigation of the RBC Velocity Fluctuations in Ex Vivo Capillaries
title_full In Silico Investigation of the RBC Velocity Fluctuations in Ex Vivo Capillaries
title_fullStr In Silico Investigation of the RBC Velocity Fluctuations in Ex Vivo Capillaries
title_full_unstemmed In Silico Investigation of the RBC Velocity Fluctuations in Ex Vivo Capillaries
title_short In Silico Investigation of the RBC Velocity Fluctuations in Ex Vivo Capillaries
title_sort in silico investigation of the rbc velocity fluctuations in ex vivo capillaries
topic LBM
IBM
DEM
FEM
RBC
capillary
url https://www.mdpi.com/2076-3417/15/14/7796
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AT ozgurekici insilicoinvestigationoftherbcvelocityfluctuationsinexvivocapillaries
AT sefikevrenerdener insilicoinvestigationoftherbcvelocityfluctuationsinexvivocapillaries