Numerical simulation of cell adhesion in microfluidic devices*

Understanding cell adhesion dynamics under fluid flow is important for many biotransport problems. We investigated the influence of cell size, ligand coating density, and micropost layout on cell adhesion in a microfluidic device. The cells were modeled as coarse grained cell membranes and the adhesion was modeled as interacting potentials, while the fluid was solved using the lattice Boltzmann method. The coupling between the cell and the fluid was achieved though the immersed boundary method. Simulation results showed that the competition between hydrodynamics and cell membrane adhesion determines the cell rolling speed and adhesion status. Higher ligand coating density and lower flow rate increase the ligand receptor interaction time and enhance the cell adhesion. The cell showed higher stress on the trailing edge of the membrane when rolling on a micropost surface. Intercellular collision can enhance or deteriorate cell adhesion, depending on the orientation of the incoming collision. Cells showed preferred adhesion in the vicinity of stagnant points, which is consistent with microfluidics based experimental results.