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Objective To study the effect of ghost red blood cells (GRBCs) on white blood cell (WBC)-mediated adhesion of tumor cells (TCs) on endothelial cells (ECs) in shear flow. Methods GRBCs with hematocrit (Hct) of 20% were added in the parallel plate flow chamber to observe changes in the number of tethered WBCs on ECs, the collision between TCs and adhesive WBCs, and the number of firmly adhered TCs at different shear rates of 62.5, 100, 200 s-1, respectively. Results GRBCs could increase the number of adhered WBCs on ECs and the collision between TCs and adhesive WBCs, and finally enhance the adhesion of TCs on ECs, especially at high shear rate (200 s-1). However, the adhesion efficiency of TCs was not significantly influenced by GRBCs. Conclusions GRBCs in shear flow can promote TC adhesion on ECs, and the research finding will provide a theoretical basis for cancer therapy.
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Objective To numerically simulate the motion characteristics of red cells in shear flow, so as to provide theoretical references for exploring pathogenesis of cardiovascular diseases and conducting experimental studies of blood circulation. Methods The hyper-elastic model of red cells with membrane thickness was established. Based on feedback force method and finite element immersed boundary method, the deformation and motion of red cells in shear flow were simulated. The solid was defined as being hyper-elastic and solved by finite element method, while the fluid was defined as incompressible Newton fluid and solved by finite difference method. Results The tank tread-like motion characteristics of red cells in shear flow were gained by numerical simulation. The simulation results in the study were consistent with the results in the literature, which validated the reliability of the proposed method in the study. Conclusions The immersed boundary method adopted in the study shows obvious advantage in solving the large deformation problem by preferably demonstrating the whole process of red cell deformation in shear flow.
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The intracellular calcium signaling, which is modulated by the microenvironment of cells, is closely related to the cell's self renewal, differentiation, proliferation, and its apoptosis. The study on the quantitative modulation of the intracellular calcium signals could not only help to understand the dynamic behavior of such kind of signaling, but also play a significant role in the control of cell fate, simulation of cell behavior and bionics of cellular biological systems. This paper briefly reviewed the progress on the quantitative modulation of intracellular calcium signals induced by shear flow, including (1) experimental phenomena and the associated mechanisms of shear flow activated intracellular calcium response; (2) mathematical modeling and simulation of the intracellular calcium response induced by shear flow; (3) feedback control of the intracellular calcium signals by shear flow.