Simulation of Deformation and Aggregation of Two Red Blood Cells in a Stenosed Microvessel by Dissipative Particle Dynamics

The motion of two red blood cells in a stenosed microvessel was simulated using dissipative particle dynamics. The effects of intercellular interaction, red blood cell deformability and the initial cell orientation on the deformation and aggregation of the RBCs and on the flow resistance were investigated. The red blood cell membrane was treated as a three-dimensional coarse-grained network model and the intercellular interaction was modeled by the Morse potential based on a depletion-mediated assumption. It is shown that the flow resistance increases dramatically when the red blood cells enter into the stenosis and decreases rapidly as RBCs move away from the stenosis. Particularly, for a pair of stiffer red blood cells with the initial inclination angle of 90°, the maximum value of the flow resistance is larger; while a higher flow resistance can also come from a stronger aggregation. For a pair of stiffer red blood cells moving parallel to the main flow, when their positions are closer to the vessel wall at the upstream of the stenosis, the flow resistance increases due to the migration to the vessel center at the stenosis. In addition, for a pair of red blood cells with the initial inclination angle of 0°, the flow resistance from the aggregate formed by a pair of red blood cells with a larger deformation is higher.