Shaping nano-/micro-particles for enhanced vascular interaction in laminar flows

Non-spherical nano-/micro-particles can drift laterally (hydrodynamic margination) in a linear laminar flow under the concurrent effect of hydrodynamic and inertial forces. Such a feature can be exploited in the rational design of particle-based intravascular and pulmonary delivery systems and for designing new flow fractioning systems for high-throughput particle separation. A general approach is presented to predict the marginating behavior of non-spherical particles. The lateral drift velocity is shown to depend on the particle Stokes number Sta and to grow with the size, density and rotational inertia of the particle. Elongated particles, in particular, low aspect ratio discoidal particles, exhibit the largest propensity to marginate in a linear laminar flow.