An investigation of endocytosis of targeted nanoparticles in a shear flow by a statistical approach

The receptor-ligand mediated endocytosis of nanoparticles by endothelium cells in a shear flow is investigated theoretically. A set of population balance equations is used to calculate the number of endocytosed nanoparticles of diameters about 100 nm for a given period of time. Hydrodynamic analysis reveals that whether a wash-out procedure is effective to remove incompletely endocytosed nanoparticles depends on the bond formation and rupture rates rather than the shear rate since the rupture rate of bonds linking nanoparticles and endothelium cells does not change with the shear rate appreciably. Furthermore, it is shown that critical bond formation and rupture rates, above which the elevation in ligand expression on cell surfaces stimulated by the shear flow will increase the number of endocytosed nanoparticles significantly, exist for typical average endocytosis durations.