3D modeling and Computational Fluid Dynamics simulations of surface-attached CHO-K1 cells going to detach from a microchannel wall

A series of steady-state Computational Fluid Dynamics simulations has been carried out to estimate the liquid flow forces acting on Chinese Hamster Ovary-K1 cells, which are necessary to detach the cells from a non-coated wall surface in a microchannel. The simulation parameters were based on experimental work of Zhang et al. [16]. Simulations were performed for cell sizes of 5 μm, 12 μm and 20 μm with three simply modeled cell shapes respectively. Additionally, a drag coefficient for each modeled cell shape was estimated. The simulation results indicate that the surface-averaged total forces, which are necessary to detach those cells, were in the nanonewton range and increase with cell size. For the force components along and perpendicular to the direction of the flow, the viscous forces accounted for the major proportion. Concerning the velocity gradients, the local energy dissipation rates reach values of at least 4e + 05 W/m3 at the top of the cell surfaces for each modeled cell shape. The drag coefficient calculations, with Reynolds numbers smaller than 1, have shown an increasing drag coefficient with a decreasing modeled cell size.

Chinese hamster ovary cells in microfluidic systems that are going to detach from a non-coated microchannel wall surface and that are exposed to shear flow are in focus. Different deformation stages of these cells were modeled and investigated in terms of forces and energy dissipation rates, which are acting onto the cell surfaces, to characterize the required loading conditions.Figure optionsDownload as PowerPoint slideHighlights
► Modeling and simulation of surface-attached cells that are exposed to shear flow
► Viscous forces show the major contribution in the forces acting in the flow direction.
► Energy dissipation rates locally reached 800 kW/m3 at cell detachment conditions.
► The drag coefficients increase with decreasing cell size.