Paolo Decuzzi

A Theoretical Model for the Margination of Particles within Blood Vessels

The margination of a particle circulating in the blood stream has been analyzed. The contribution of buoyancy, hemodynamic forces, van der Waals, electrostatic and steric interactions between the circulating particle and the endothelium lining the vasculature has been considered. For practical applications, the contribution of buoyancy, hemodynamic forces and van der Waals interactions should be only taken into account, whilst the effect of electrostatic and steric repulsion becomes important only at very short distances from the endothelium (1–10 nm). The margination speed and the time for margination ts have been estimated as a function of the density of the particle relative to blood Δ ρ, the Hamaker constant A and radius R of the particle. A critical radius Rc exists for which the margination time ts has a maximum, which is influenced by both Δ ρ and A: the critical radius decreases as the relative density increases and the Hamaker constant decreases. Therefore, particles used for drug delivery should have a radius smaller than the critical value (in the range of 100 nm) to facilitate margination and interaction with the endothelium. While particles used as nanoharvesting agents in proteomics or genomics analysis should have a radius close to the critical value to minimize margination and increase their circulation time.

The effective dispersion of nanovectors within the tumor microvasculature

The effective longitudinal diffusion of nanovectors along non-permeable and permeable capillaries has been studied considering the contribution of molecular and convective diffusion based on the Taylors theory of shear dispersion. The problem is of importance in the transport of nanovectors used for the intravascular delivery of drugs and contrast agents.It has been shown that for a given capillary size and hemodynamic conditions a critical radius

Adhesion of Microfabricated Particles on Vascular Endothelium: A Parametric Analysis

a_{rm cr}

Frictionally Excited Thermoelastic Instability in Multi-Disk Clutches and Brakes

exists for which the effective longitudinal diffusion along the capillary has a minimum: Nanovectors with

Transient analysis of frictionally excited thermoelastic instability in multi-disk clutches and brakes

aa_{rm cr}

Elastic beam over an adhesive wavy foundation

diffuse mainly by convection and the effective diffusion coefficient grows with