Numerical simulation of forces on a spreading cell exposed to flow

When spreading cells are briefly exposed to flow, cell detachment is influenced by both the number of bonds formed and by the shape of the cell. Previous studies indicate a relationship between cell spreading and adhesion. Spreading cells exhibit a variety of shapes, ranging from a sphere upon initial attachment, to a bulbous shape attached to the surface by one or more processes, to a flattened shape when completely spread. The shape of the cell affects the shear stress distribution along the cell surface. A two dimensional model of flow over a spreading cell in a parallel flat plate flow chamber is developed. The model consists of a finite element grid developed by using the software package FIDAP (Fluid Dynamics International). The governing differential equations are the Navier-Stokes equations with constant density and viscosity. Channei Reynold's numbers range from 50 to 200. Channel height to cell height ratio is at least 20:1. The shear stress distribution is calculated along the cell surface. The distribution is then integrated to obtain the resultant forces. These forces are then used in a simple kinetic model of cellular adhesion, to predict the onset of detachment. When the forces on the cell exceed the maximum allowable stress on all the bonds, cell detachment occurs.

Duke Scholars

Author George A. Truskey Biomedical Engineering