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Article: Simulation of blood flow in a sudden expansion channel and a coronary artery.

Wu, Wei-Tao / Aubry, Nadine / Antaki, James F / Massoudi, Mehrdad

Journal of computational and applied mathematics

2020 Volume 376

Abstract: In this paper, we numerically simulate the flow of blood in two benchmark problems: the flow in a sudden expansion channel and the flow through an idealized curved coronary artery with pulsatile inlet velocity. Blood is modeled as a suspension (a non- ... ...

Abstract	In this paper, we numerically simulate the flow of blood in two benchmark problems: the flow in a sudden expansion channel and the flow through an idealized curved coronary artery with pulsatile inlet velocity. Blood is modeled as a suspension (a non-linear complex fluid) and the movement of the red blood cell (RBCs) is modeled by using a concentration flux equation. The viscosity of blood is obtained from experimental data. In the sudden expansion flow, the predicted velocity profiles for two different Reynolds numbers (based on the inlet velocity) agree well with the available experiments; furthermore, the numerical results also show that after the sudden expansion there exists a RBCs depletion region. For the second problem, the idealized curved coronary artery, it is found that the RBCs move towards and concentrate near the inner surface where the viscosity is higher and the shear stress lower; this phenomenon may be related to the atherosclerotic plaque formation which usually occurs on the inside surface of the arteries.
Language	English
Publishing date	2020-03-19
Publishing country	Belgium
Document type	Journal Article
ZDB-ID	1468806-2
ISSN	0377-0427
ISSN	0377-0427
DOI	10.1016/j.cam.2020.112856
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Article ; Online: β-Dispersion of blood during sedimentation.

Sabuncu, Ahmet C / Muldur, Sinan / Cetin, Barbaros / Usta, O Berk / Aubry, Nadine

Scientific reports

2021 Volume 11, Issue 1, Page(s) 2642

Abstract: Aggregation of human red blood cells (RBC) is central to various pathological conditions from bacterial infections to cancer. When left at low shear conditions or at hemostasis, RBCs form aggregates, which resemble stacks of coins, known as 'rouleaux'. ... ...

Abstract	Aggregation of human red blood cells (RBC) is central to various pathological conditions from bacterial infections to cancer. When left at low shear conditions or at hemostasis, RBCs form aggregates, which resemble stacks of coins, known as 'rouleaux'. We experimentally examined the interfacial dielectric dispersion of aggregating RBCs. Hetastarch, an RBC aggregation agent, is used to mimic conditions leading to aggregation. Hetastrach concentration is incrementally increased in blood from healthy donors to measure the sensitivity of the technique. Time lapse electrical impedance measurements were conducted as red blood cells form rouleaux and sediment in a PDMS chamber. Theoretical modeling was used for obtaining complex permittivity of an effective single red blood cell aggregate at various concentrations of hetastarch. Time response of red blood cells' impedance was also studied to parametrize the time evolution of impedance data. Single aggregate permittivity at the onset of aggregation, evolution of interfacial dispersion parameters, and sedimentation kinetics allowed us to distinguish differential aggregation in blood.
MeSH term(s)	Blood Sedimentation/drug effects ; Erythrocyte Aggregation/drug effects ; Erythrocyte Aggregation/physiology ; Erythrocytes/drug effects ; Erythrocytes/physiology ; Hemorheology ; Hemostasis/drug effects ; Humans ; Hydroxyethyl Starch Derivatives/pharmacology ; Kinetics ; Models, Theoretical ; Physical Phenomena
Chemical Substances	Hydroxyethyl Starch Derivatives
Language	English
Publishing date	2021-01-29
Publishing country	England
Document type	Journal Article ; Research Support, N.I.H., Extramural
ZDB-ID	2615211-3
ISSN	2045-2322 ; 2045-2322
ISSN (online)	2045-2322
ISSN	2045-2322
DOI	10.1038/s41598-021-82171-x
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Article ; Online: Copolymers Derived from Two Active Esters: Synthesis, Characterization, Thermal Properties, and Reactivity in Post-Modification.

Nguyen, Thi Phuong Thu / Barroca-Aubry, Nadine / Aymes-Chodur, Caroline / Dragoe, Diana / Pembouong, Gaëlle / Roger, Philippe

Molecules (Basel, Switzerland)

2022 Volume 27, Issue 20

Abstract: Copolymers with two distinguished reactive repeating units are of great interest, as such copolymers might open the possibility of obtaining selective and/or consequent copolymers with different chemical structures and properties. In the present work, ... ...

Abstract	Copolymers with two distinguished reactive repeating units are of great interest, as such copolymers might open the possibility of obtaining selective and/or consequent copolymers with different chemical structures and properties. In the present work, copolymers based on two active esters (pentafluorophenyl methacrylate and
Language	English
Publishing date	2022-10-12
Publishing country	Switzerland
Document type	Journal Article
ZDB-ID	1413402-0
ISSN	1420-3049 ; 1431-5165 ; 1420-3049
ISSN (online)	1420-3049
ISSN	1431-5165 ; 1420-3049
DOI	10.3390/molecules27206827
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Article: A non-linear fluid suspension model for blood flow.

Wu, Wei-Tao / Aubry, Nadine / Antaki, James F / Massoudi, Mehrdad

International journal of non-linear mechanics

2018 Volume 109, Page(s) 32–39

Abstract: Motivated by the complex rheological behaviors observed in small/micro scale blood vessels, such as the Fahraeus effect, plasma-skimming, shear-thinning, etc., we develop a non-linear suspension model for blood. The viscosity is assumed to depend on the ... ...

Abstract	Motivated by the complex rheological behaviors observed in small/micro scale blood vessels, such as the Fahraeus effect, plasma-skimming, shear-thinning, etc., we develop a non-linear suspension model for blood. The viscosity is assumed to depend on the volume fraction (hematocrit) and the shear rate. The migration of the red blood cells (RBCs) is studied using a concentration flux equation. A parametric study with two representative problems, namely simple shear flow and a pressure driven flow demonstrate the ability of this reduced-order model to reproduce several key features of the two-fluid model (mixture theory approach), with much lower computational cost.
Language	English
Publishing date	2018-11-09
Publishing country	Netherlands
Document type	Journal Article
ZDB-ID	2006564-4
ISSN	0020-7462
ISSN	0020-7462
DOI	10.1016/j.ijnonlinmec.2018.11.002
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Article: Simulation of thrombosis in a stenotic microchannel: The effects of vWF-enhanced shear activation of platelets.

Wu, Wei-Tao / Zhussupbekov, Mansur / Aubry, Nadine / Antaki, James F / Massoudi, Mehrdad

International journal of engineering science

2019 Volume 147

Abstract: This study was undertaken to develop a numerical/computational simulation of von Willebrand Factor (vWF) - mediated platelet shear activation and deposition in an idealized stenosis. Blood is treated as a multi-constituent mixture comprised of a linear ... ...

Abstract	This study was undertaken to develop a numerical/computational simulation of von Willebrand Factor (vWF) - mediated platelet shear activation and deposition in an idealized stenosis. Blood is treated as a multi-constituent mixture comprised of a linear fluid component and a porous solid component (thrombus). Chemical and biological species involved in coagulation are modeled using a system of coupled convection-reaction-diffusion (CRD) equations. This study considers the cumulative effect of shear stress (history) on platelet activation. The vWF activity is modeled as an enhancement function for the shear stress accumulation and is related to the experimentally-observed unfolding rate of vWF. A series of simulations were performed in an idealized stenosis in which the predicted platelets deposition agreed well with previous experimental observations spatially and temporally, including the reduction of platelet deposition with decreasing expansion angle. Further simulation indicated a direct relationship between vWF-mediated platelet deposition and degree of stenosis. Based on the success with these benchmark simulations, it is hoped that the model presented here may provide additional insight into vWF-mediated thrombosis and prove useful for the development of more hemo-compatible blood-wetted devices in the future.
Language	English
Publishing date	2019-12-20
Publishing country	England
Document type	Journal Article
ZDB-ID	1484471-0
ISSN	0020-7225
ISSN	0020-7225
DOI	10.1016/j.ijengsci.2019.103206
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Article ; Online: Post-Modification of Copolymers Obtained by ATRP for an Application in Heterogeneous Asymmetric Salen Catalysis.

Bakangura, Erigene / Roger, Philippe / Soares, Rafaela S B / Mellah, Mohamed / Barroca-Aubry, Nadine / Gouget-Laemmel, Anne-Chantal / Ozanam, François / Costa, Ludovic / Baltaze, Jean-Pierre / Schulz, Emmanuelle

Molecules (Basel, Switzerland)

2022 Volume 27, Issue 14

Abstract: Copolymers are valuable supports for obtaining heterogeneous catalysts that allow their recycling and therefore substantial savings, particularly in the field of asymmetric catalysis. This contribution reports the use of two comonomers: Azido-3- ... ...

Abstract	Copolymers are valuable supports for obtaining heterogeneous catalysts that allow their recycling and therefore substantial savings, particularly in the field of asymmetric catalysis. This contribution reports the use of two comonomers: Azido-3-propylmethacrylate (AZMA) bearing a reactive azide function was associated with 2-methoxyethyl methacrylate (MEMA), used as a spacer, for the ATRP synthesis of copolymers, and then post-functionalized with a propargyl chromium salen complex. The controlled homopolymerization of MEMA by ATRP was firstly described and proved to be more controlled in molar mass than that of AZMA for conversions up to 63%. The ATRP copolymerization of both monomers made it possible to control the molar masses and the composition, with nevertheless a slight increase in the dispersity (from 1.05 to 1.3) when the incorporation ratio of AZMA increased from 10 to 50 mol%. These copolymers were post-functionalized with chromium salen units by click chemistry and their activity was evaluated in the asymmetric ring opening of cyclohexene oxide with trimethylsilyl azide. At an equal catalytic ratio, a significant increase in enantioselectivity was obtained by using the copolymer containing the largest part of salen units, probably allowing, in this case, the more favorable bimetallic activation of both the engaged nucleophile and electrophile. Moreover, the catalytic polymer was recovered by simple filtration and re-engaged in subsequent catalytic runs, up to seven times, without loss of activity or selectivity.
MeSH term(s)	Catalysis ; Chromium ; Ethylenediamines/chemistry ; Polymers/chemistry
Chemical Substances	Ethylenediamines ; Polymers ; Chromium (0R0008Q3JB) ; disalicylaldehyde ethylenediamine (94-93-9)
Language	English
Publishing date	2022-07-21
Publishing country	Switzerland
Document type	Journal Article
ZDB-ID	1413402-0
ISSN	1420-3049 ; 1431-5165 ; 1420-3049
ISSN (online)	1420-3049
ISSN	1431-5165 ; 1420-3049
DOI	10.3390/molecules27144654
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Article ; Online: Multi-Constituent Simulation of Thrombus Deposition.

Wu, Wei-Tao / Jamiolkowski, Megan A / Wagner, William R / Aubry, Nadine / Massoudi, Mehrdad / Antaki, James F

Scientific reports

2017 Volume 7, Page(s) 42720

Abstract: In this paper, we present a spatio-temporal mathematical model for simulating the formation and growth of a thrombus. Blood is treated as a multi-constituent mixture comprised of a linear fluid phase and a thrombus (solid) phase. The transport and ... ...

Abstract	In this paper, we present a spatio-temporal mathematical model for simulating the formation and growth of a thrombus. Blood is treated as a multi-constituent mixture comprised of a linear fluid phase and a thrombus (solid) phase. The transport and reactions of 10 chemical and biological species are incorporated using a system of coupled convection-reaction-diffusion (CRD) equations to represent three processes in thrombus formation: initiation, propagation and stabilization. Computational fluid dynamic (CFD) simulations using the libraries of OpenFOAM were performed for two illustrative benchmark problems: in vivo thrombus growth in an injured blood vessel and in vitro thrombus deposition in micro-channels (1.5 mm × 1.6 mm × 0.1 mm) with small crevices (125 μm × 75 μm and 125 μm × 137 μm). For both problems, the simulated thrombus deposition agreed very well with experimental observations, both spatially and temporally. Based on the success with these two benchmark problems, which have very different flow conditions and biological environments, we believe that the current model will provide useful insight into the genesis of thrombosis in blood-wetted devices, and provide a tool for the design of less thrombogenic devices.
MeSH term(s)	Computer Simulation ; Heart Diseases/physiopathology ; Humans ; Hydrodynamics ; Models, Cardiovascular ; Thrombosis/physiopathology
Language	English
Publishing date	2017-02-20
Publishing country	England
Document type	Journal Article ; Research Support, N.I.H., Extramural
ZDB-ID	2615211-3
ISSN	2045-2322 ; 2045-2322
ISSN (online)	2045-2322
ISSN	2045-2322
DOI	10.1038/srep42720
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Article: Physics underlying controlled self-assembly of micro- and nanoparticles at a two-fluid interface using an electric field.

Aubry, Nadine / Singh, Pushpendra

Physical review. E, Statistical, nonlinear, and soft matter physics

2008 Volume 77, Issue 5 Pt 2, Page(s) 56302

Abstract: The purpose of this paper is to investigate the physics underlying the controlled self-assembly of microparticles and nanoparticles at a two-fluid interface using an electric field. As shown in recent experiments, under certain conditions an externally ... ...

Abstract	The purpose of this paper is to investigate the physics underlying the controlled self-assembly of microparticles and nanoparticles at a two-fluid interface using an electric field. As shown in recent experiments, under certain conditions an externally applied electric field can cause particles floating at a two-fluid interface to assemble into a virtually defect free monolayer whose lattice spacing can be adjusted by varying the electric field strength. In this work, we assume that both fluids and particles are perfect dielectrics and for this case analyze the (capillary and electrical) forces acting on the particles, deduce an expression for the lattice spacing under equilibrium condition, and study the dependence of the latter upon the various parameters of the system, including the particles' radius, the dielectric properties of the fluids and particles, the particles' position within the interface, the particles' buoyant weight, and the applied voltage. While for relatively large sized particles whose buoyant weight is much larger than the vertical electrostatic force, the equilibrium distance increases with increasing electric field, for submicron sized particles whose buoyant weight is negligible, it decreases with increasing electric field. For intermediate sized particles, the distance first increases and then decreases with increasing electric field strength.
Language	English
Publishing date	2008-05
Publishing country	United States
Document type	Journal Article
ISSN	1539-3755
ISSN	1539-3755
DOI	10.1103/PhysRevE.77.056302
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Article ; Online: High fidelity computational simulation of thrombus formation in Thoratec HeartMate II continuous flow ventricular assist device.

Wu, Wei-Tao / Yang, Fang / Wu, Jingchun / Aubry, Nadine / Massoudi, Mehrdad / Antaki, James F

Scientific reports

2016 Volume 6, Page(s) 38025

Abstract: Continuous flow ventricular assist devices (cfVADs) provide a life-saving therapy for severe heart failure. However, in recent years, the incidence of device-related thrombosis (resulting in stroke, device-exchange surgery or premature death) has been ... ...

Abstract	Continuous flow ventricular assist devices (cfVADs) provide a life-saving therapy for severe heart failure. However, in recent years, the incidence of device-related thrombosis (resulting in stroke, device-exchange surgery or premature death) has been increasing dramatically, which has alarmed both the medical community and the FDA. The objective of this study was to gain improved understanding of the initiation and progression of thrombosis in one of the most commonly used cfVADs, the Thoratec HeartMate II. A computational fluid dynamics simulation (CFD) was performed using our recently updated mathematical model of thrombosis. The patterns of deposition predicted by simulation agreed well with clinical observations. Furthermore, thrombus accumulation was found to increase with decreased flow rate, and can be completely suppressed by the application of anticoagulants and/or improvement of surface chemistry. To our knowledge, this is the first simulation to explicitly model the processes of platelet deposition and thrombus growth in a continuous flow blood pump and thereby replicate patterns of deposition observed clinically. The use of this simulation tool over a range of hemodynamic, hematological, and anticoagulation conditions could assist physicians to personalize clinical management to mitigate the risk of thrombosis. It may also contribute to the design of future VADs that are less thrombogenic.
MeSH term(s)	Anticoagulants/therapeutic use ; Computer Simulation ; Female ; Heart-Assist Devices/adverse effects ; Hemodynamics ; Humans ; Hydrodynamics ; Male ; Pulsatile Flow ; Surface Properties ; Thrombosis/drug therapy ; Thrombosis/etiology
Chemical Substances	Anticoagulants
Language	English
Publishing date	2016-12-01
Publishing country	England
Document type	Journal Article ; Research Support, N.I.H., Extramural
ZDB-ID	2615211-3
ISSN	2045-2322 ; 2045-2322
ISSN (online)	2045-2322
ISSN	2045-2322
DOI	10.1038/srep38025
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Article: Design of microfluidic channels for magnetic separation of malaria-infected red blood cells.

Wu, Wei-Tao / Martin, Andrea Blue / Gandini, Alberto / Aubry, Nadine / Massoudi, Mehrdad / Antaki, James F

Microfluidics and nanofluidics

2016 Volume 20, Issue 2

Abstract: This study is motivated by the development of a blood cell filtration device for removal of malaria-infected, parasitized red blood cells (pRBCs). The blood was modeled as a multi-component fluid using the computational fluid dynamics discrete element ... ...

Abstract	This study is motivated by the development of a blood cell filtration device for removal of malaria-infected, parasitized red blood cells (pRBCs). The blood was modeled as a multi-component fluid using the computational fluid dynamics discrete element method (CFD-DEM), wherein plasma was treated as a Newtonian fluid and the red blood cells (RBCs) were modeled as soft-sphere solid particles which move under the influence of drag, collisions with other RBCs, and a magnetic force. The CFD-DEM model was first validated by a comparison with experimental data from Han et al. 2006 (Han and Frazier 2006) involving a microfluidic magnetophoretic separator for paramagnetic deoxygenated blood cells. The computational model was then applied to a parametric study of a parallel-plate separator having hematocrit of 40% with a 10% of the RBCs as pRBCs. Specifically, we investigated the hypothesis of introducing an upstream constriction to the channel to divert the magnetic cells within the near-wall layer where the magnetic force is greatest. Simulations compared the efficacy of various geometries upon the stratification efficiency of the pRBCs. For a channel with nominal height of 100 µm, the addition of an upstream constriction of 80% improved the proportion of pRBCs retained adjacent to the magnetic wall (separation efficiency) by almost 2 fold, from 26% to 49%. Further addition of a downstream diffuser reduced remixing, hence improved separation efficiency to 72%. The constriction introduced a greater pressure drop (from 17 to 495 Pa), which should be considered when scaling-up this design for a clinical-sized system. Overall, the advantages of this design include its ability to accommodate physiological hematocrit and high throughput - which is critical for clinical implementation as a blood-filtration system.
Language	English
Publishing date	2016-02-02
Publishing country	Germany
Document type	Journal Article
ZDB-ID	2155772-X
ISSN	1613-4990 ; 1613-4982
ISSN (online)	1613-4990
ISSN	1613-4982
DOI	10.1007/s10404-016-1707-4
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