Adhesion of microfabricated particles on vascular endothelium: a parametric analysis.

"Smart" drug delivery systems should be selective and effective to ensure drug administration at the right time, at the right dosage, and anywhere in the body. Among the several administration routes and delivery systems that have been proposed, one of the most effective and promising is based on microfabricated particles injected directly into the blood stream. The shape, size, and material properties of the particles can be designed and optimized depending on the specific applications and targets (cell, tissue, or circulating virus). Since the binding affinity of particles to cells is affected by both the binding force and its growth rate with time, it is of great importance to consider the viscous response of the system. In this work, a parametric analysis is presented where the probability of adhesion of a microfabricated particle on the endothelium is expressed as a function of (i) the hemodynamic conditions, (ii) the viscoelastic properties of the particle and targeted cell, and (iii) density of ligands grafted over the particle. Criteria for the optimal design of particles are proposed.