Regensburg 2007 – scientific programme
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BP: Fachverband Biologische Physik
BP 5: Cell Adhesion
BP 5.2: Talk
Monday, March 26, 2007, 11:00–11:15, H44
Efficiency of Initiating Cell Adhesion in Hydrodynamic Flow — •Christian Korn1,2 and Ulrich Schwarz1 — 1University of Heidelberg, Im Neuenheimer Feld 293, D-69120 Heidelberg, Germany — 2Max Planck Institute of Colloids and Interfaces, D-14424 Potsdam, Germany
Motivated by the importance of cell adhesion under flow for various biological and biotechnological applications, we theoretically investigate the efficiency of initial binding between a receptor-coated sphere and a ligand-coated wall in linear shear flow. Using a Langevin equation that accounts for both hydrodynamic interactions and Browian motion, we numerically calculate the mean first passage time (MFPT) for receptor-ligand encounter. We study the influence of flow rate, receptor and ligand coverage, as well as receptor patch geometry on the MFPT. With increasing shear rate, the MFPT always decreases monotonically. Above a threshold value of a few hundreds, binding efficiency is enhanced only weakly upon increasing the number of receptor patches. Regarding receptor geometry, increasing height increases binding efficiency much stronger than increasing lateral size. This explains why white blood cells adhere to the vessel walls through receptor patches localized to the tips of microvilli, and why malaria-infected red blood cells form elevated receptor patches (knobs).
[1] C. Korn and U. S. Schwarz, Phys. Rev. Lett. 97: 138103, 2006.