Efficiency of initiating cell adhesion in hydrodynamic flow

C. Korn and U. S. Schwarz

Phys. Rev. Lett. 97: 138103 (2006)

We theoretically investigate the efficiency of initial binding between
a receptor-coated sphere and a ligand-coated wall in linear shear
flow. The mean first passage time for binding decreases monotonically
with increasing shear rate. Above a saturation threshold of the order
of a few 100 receptor patches, the binding efficiency is enhanced only
weakly by increasing their number and size, but strongly by increasing
their height. This explains why white blood cells in the blood flow
adhere through receptor patches localized to the tips of microvilli,
and why malaria-infected red blood cells form elevated receptor
patches (knobs).