Evaluation of computational errors in a red blood cell model of the dissipative particle dynamics method

A biological cell exhibits viscoelastic behavior mainly because its components (membrane and cytoplasm) are viscoelastic, and this is clearly seen when it is stretched and released. The present work numerically studied the shape recovery of a red blood cell (RBC) based on a viscoelastic model at the meso-scale using Dissipative Particle Dynamics (DPD) method. In this model, the RBC membrane is represented by a triangular network of worm-like chains, while the cytoplasm is replaced by a system of DPD particles. This viscoelastic model is validated by examining the stretching deformation of an RBC and comparing with the existing experimental data. Viscoelastic properties of the RBC are then analyzed by stretching an RBC under a 20 pN stretching force, and allowing it to relax. The time to recover its shape upon removal of the stretching force is measured to be 111 and 92.6[Formula: see text]ms for an RBC with and without cytoplasm, and the corresponding membrane viscosity is [Formula: see text] and [Formula: see text] [Formula: see text], respectively. These values, for an RBC with cytoplasm, are closer to experimental data than those for an RBC without cytoplasm, lending support to the model with cytoplasm. Finally, parametric studies are conducted on the membrane elastic and bending moduli. The results show that the shape recovery time decreases with increasing the membrane elastic and bending moduli.

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APPLICATION OF DISSIPATIVE PARTICLE DYNAMICS TO THE STUDY OF A RED BLOOD CELL IN SIMPLE SHEAR FLOW

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194514603731 ◽

2014 ◽

Vol 34 ◽

pp. 1460373

Author(s):

TING YE ◽

NHAN PHAN-THIEN ◽

BOO CHEONG KHOO ◽

CHWEE TECK LIM

Keyword(s):

Shear Flow ◽

Blood Cell ◽

Simple Shear ◽

Red Blood Cell ◽

Dissipative Particle Dynamics ◽

Particle Dynamics ◽

Simple Shear Flow ◽

Past Study ◽

Computational Domain ◽

Membrane Particles

The present work reports an attempt to apply the dissipative particle dynamics (DPD) method to study the dynamic behaviors of a red blood cell (RBC) in simple shear flow. The simulation system is discretized into four types of particles, namely wall particles, fluid particles, membrane particles and internal particles. The particle interaction is modeled by the DPD method, and the membrane particles are connected into a viscoelastic triangular network to represent the RBC membrane. As benchmarking tests, we simulate the deformation of a spherical capsule in shear flow and compare it with the past study, and also examine the effect of computational domain size. After that, we investigate the dynamics of a RBC in shear flow at different membrane shear and bending moduli. Our simulations reproduce the tank-treading, trembling and tumbling motions of the RBC at the shear modulus Es = 6, 60 and 600 μN/m, respectively. Moreover, we find that the RBC undergoes a trembling motion when its bending modulus is large enough, where the obvious stretching and smoothing of the RBC occur alternately in shape.

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