Multiscale method based on coupled lattice‐Boltzmann and Langevin‐dynamics for direct simulation of nanoscale particle/polymer suspensions in complex flows

Computer simulations were performed to study the transport of red blood cells and platelets in high shear flows, mimicking earlier published in vitro experiments in microfluidic devices with high affinity for platelet aggregate formation. The goal is to understand and predict where thrombus formation starts. Additionally, the need of cell-based modelling in these microfluidic devices is demonstrated by comparing our results with macroscopic models, wherein blood is modelled as a continuous fluid. Hemocell, a cell-based blood flow simulation framework is used to investigate the transport physics in the microfluidic devices. The simulations show an enlarged cell-depleted layer at the site where a platelet aggregate forms in the experiments. In this enlarged cell-depleted layer, the probability to find a platelet is higher than in the rest of the microfluidic device. In addition, the shear rates are sufficiently high to allow for the von Willebrand factor to elongate in this region. We hypothesize that the enlarged cell-depleted layer combined with a sufficiently large platelet flux and sufficiently high shear rates result in an haemodynamic environment that is a preferred location for initial platelet aggregation.

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“…[29] and Lui et al . [30] included the vWF in their cell-based model to study the behaviour of this protein in the blood. Griffin et al .…”

Section: Introductionmentioning

confidence: 99%

Identifying the start of a platelet aggregate by the shear rate and the cell-depleted layer

Rooij

Závodszky

Tarksalooyeh

et al. 2019

J. R. Soc. Interface.

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“…In this work, we employ a recently developed 3D multiscale and multicomponent blood flow solver 2,28,29,31 to tackle the dispersive characteristics of spherical, rigid particles with sizes spanning nano-to-microscale in a tubular blood flow. Particle suspension dynamics in the presence of thermal fluctuation, RBC-particle direct and hydrodynamic interactions and wall-bounded confinement effect are captured under a unified 3D computational framework.…”

Section: Introductionmentioning

confidence: 99%

A unified analysis of nano-to-microscale particle dispersion in tubular blood flow

et al. 2019

Self Cite

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Transport of solid particles in blood flow exhibits qualitative differences in the transport mechanism when the particle varies from nanoscale to microscale size comparable to the red blood cell (RBC). The effect of microscale particle margination has been investigated by several groups. Also, the transport of nanoscale particles (NPs) in blood has received considerable attention in the past. This study attempts to bridge the gap by quantitatively showing how the transport mechanism varies with particle size from nano-to microscale. Using a three-dimensional (3D) multiscale method, the dispersion of particles in microscale tubular flows is investigated for various hematocrits, vessel diameters and particle sizes. NPs exhibit a nonuniform, smoothly-dispersed distribution across the tube radius due to severe Brownian motion. The near-wall concentration of NPs can be moderately enhanced by increasing hematocrit and confinement. Moreover, there exists a critical particle size (∼1 µm) that leads to excessive retention of particles in the cell-free region near the wall, i.e., margination. Above this threshold, the margination propensity increases with the particle size. The dominance of RBC-enhanced shear-induced diffusivity (RESID) over Brownian diffusivity (BD) results in 10 times higher radial diffusion rates in the RBC-laden region compared to that in the cell-free layer, correlated with the high margination propensity of microscale particles. This work captures the particle sizedependent transition from Brownian-motion dominant dispersion to margination using a unified 3D multiscale computational approach, and highlights the linkage between the radial distribution of RESID and the margination of particles in confined blood flows.

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“…Under low Reynolds number conditions, the inertial effect can be neglected. The motion of the as-prepared Mg-based micromotor can be described by a set of differential equations for translation and rotation [46][47][48]:…”

Section: Resultsmentioning

confidence: 99%

Mg-Based Micromotors with Motion Responsive to Dual Stimuli

Xiong

Lin

et al. 2020

Research

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Mg-based micromotors have emerged as an extremely attractive artificial micro/nanodevice, but suffered from uncontrollable propulsion and limited motion lifetime, restricting the fulfillment of complex tasks. Here, we have demonstrated Mg-based micromotors composed of Mg microspheres asymmetrically coated with Pt and temperature-sensitive poly(N-isopropylacrylamide) (PNIPAM) hydrogel layers in sequence. They can implement different motion behaviors stemming from the driving mechanism transformation when encountering catalyzed substrates such as H2O2 and respond to both H2O2 concentration and temperature in aqueous environment. The as-constructed Mg-based micromotors are self-propelled by Pt-catalyzed H2O2 decomposition following the self-consuming Mg-H2O reaction. In this case, they could further generate bilateral bubbles and thus demonstrate unique self-limitation motion like hovering when the phase transformation of PNIPAM is triggered by decreasing temperature or when the H2O2 concentration after permeating across the PNIPAM hydrogel layer is high enough to facilitate bubble nucleation. Our work for the first time provides a stimuli-induced “hovering” strategy for self-propelled micromotors, which endows Mg-based micromotors with an intelligent response to the surroundings besides the significant extension of their motion lifetime.

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Multiscale method based on coupled lattice‐Boltzmann and Langevin‐dynamics for direct simulation of nanoscale particle/polymer suspensions in complex flows

Cited by 32 publications

References 78 publications

Identifying the start of a platelet aggregate by the shear rate and the cell-depleted layer

Identifying the start of a platelet aggregate by the shear rate and the cell-depleted layer

A unified analysis of nano-to-microscale particle dispersion in tubular blood flow

Mg-Based Micromotors with Motion Responsive to Dual Stimuli

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