The Transport of Nanoparticles in Blood Vessels: The Effect of Vessel Permeability and Blood Rheology

The longitudinal transport of nanoparticles in blood vessels has been analyzed with blood described as a Casson fluid. Starting from the celebrated Taylor and Aris theory, an explicit expression has been derived for the effective longitudinal diffusion (D _eff) depending non-linearly on the rheological parameter ξ_c, the ratio between the plug and the vessel radii; and on the permeability parameters $\Uppi$ and $\Upomega ,$ related to the hydraulic conductivity and pressure drop across the vessel wall, respectively. An increase of ξ_c or $\Uppi$ has the effect of reducing D _eff, and thus both the rheology of blood and the permeability of the vessels may constitute a physiological barrier to the intravascular delivery of nanoparticles.