A Particle Dynamic Model of Red Blood Cell Aggregation Kinetics

Abstract

To elucidate the relationship between microscopic red blood cell (RBC) interactions and macroscopic rheological behavior, we propose a two-dimensional particle model capable of mimicking the main characteristics of RBC aggregation kinetics. The mechanical model of RBCs sheared in Couette flow is based on Newton law. We assumed a hydrodynamic force to move particles, a force to describe aggregation and an elasticity force. The role of molecular mass and concentration of neutral polymers on aggregation [Neu, B., and H. J. Meiselman. Biophys. J. 83:2482-2490, 2002] could be mimicked. Specifically, it was shown that for any shear rate (SR), the mean aggregate size (MAS) grew with time until it reached a constant value, which is consistent with in vitro experiments. It was also demonstrated that we could mimic the modal relationship between MAS and SR and the occurrence of maximum aggregation at about 0.1 s(-1). As anticipated, simulations indicated that an increase in aggregation force augmented MAS. Further, augmentation of the depletion layer thickness influenced MAS only for SR close to zero, which is a new finding. To conclude, our contribution reveals that the aggregation force intensity and SR influence the steady state MAS, and that the depletion and layer thickness affect the aggregation speed.

Optically clear biomicroviscometer with modular geometry using disposable PDMS chips

“…Owens [3] derived a microstructure based constitutive equation considering the elastic stress and average aggregate size, which closely agreed with the experimental data from Bureau et al [7], and indicated stress hysteresis with viscoelastic and shear thinning properties. Fenech et al [8] derived a particle-based equation considering the elastic and aggregation forces, which also closely agreed with the experimental data from Bureau et al [7] and model from Owens [3], when comparing the mean average aggregate size of RBCs to the shear rate.…”

“…Constitutive models have since been proposed to model the aggregation and disaggregation of blood [3], [8], which agree with the experimental data from Bureau et al [7]. Owens [3] derived a microstructure based constitutive equation considering the elastic stress and average aggregate size, which closely agreed with the experimental data from Bureau et al [7], and indicated stress hysteresis with viscoelastic and shear thinning properties.…”

“…In this thesis work, we aim to investigate the rheology of blood in the microcirculation. More specifically, we aim to investigate the viscous behaviour of blood, which has often been reduced to an equivalent viscosity in a single microchannel [3], [8], and we will consider the network as a whole.…”

“…The effect of shear rate on aggregation of RBCs has been investigated extensively [3], [7], [8], [26]. At high shear rates, the RBCs do not have sufficient time to interact with each other, and the flow forces are too great for them to aggregate.…”

Hemodynamics in the Microcirculation and in Microfluidics

“…In most previous numerical studies regarding rouleaux formations; 42,84,164 however, simple potential functions were used to compute cell-cell interactions. To accurately predict rouleaux formation, we must solve hydrodynamic interactions between cells more precisely.…”