Nanoparticle diffusion in sheared cellular blood flow*

We apply a three-dimensional lattice-Boltzmann based multiscale and multicomponent blood flow solver to interrogate the mechanisms of enhanced nanoparticle (NP) diffusion in blood flow over a wide range of shear rate and hematocrit. Anomalous dispersive behavior is observed in the transient NP-red blood cell (RBC) interaction. In the long-time asymptotic regime, the cross-stream diffusivity exhibits sublinear scales, while the longitudinal diffusivity shows superlinear scale. The deviation from classical linear shear-rate scaling is attributed to the morphological change of RBC under shear. This work provides insight in the design of optimal nano-drug systems and creates a more precise constitutive link between the hemorheological properties and the NP diffusion due to interaction with RBC (RBC-enhance diffusion) and Brownian effects in blood flow.