%0 Journal Article
%T The margination propensity of spherical particles for vascular targeting in the microcirculation
%A Francesco Gentile
%A Antonio Curcio
%A Ciro Indolfi
%A Mauro Ferrari
%A Paolo Decuzzi
%J Journal of Nanobiotechnology
%D 2008
%I BioMed Central
%R 10.1186/1477-3155-6-9
%X In the early diagnosis, treatment and imaging of diseases, as cancer and cardiovascular, the use of microparticles and nanoparticles is emerging as a powerful tool [1,2]. These are sufficiently small 'vectors' of therapeutic or/and imaging agents to be systemically administered, transported by the blood flow along the circulatory system and eventually recognize the diseased microenvironment (diseased cells). A nanoparticle comprises an internal core with the active agents and an external coating whit tailored physico-chemical properties. The interaction of the vectors with the biological target (diseased cell) is generally governed by specific forces, mediated by the formation and destruction of molecular bonds [3], and by non-specific interactions regulated by short ranged forces as van der Waals, electrostatic and steric [4].Two different delivery strategies are currently under investigation and development: a passive targeting of the diseased microenvironment relying on the permeability of the blood vessels (enhanced retention and permeability effect), and an active targeting of the diseased microvasculature relying on the recognition of specific molecules overexpressed at the site of interest [5]. It is known that tumor microvessels exhibit a significant increase in permeability to large molecules with intercellular openings and intercellular gaps as large as a micron [6], which could be crossed by sufficiently small particles. However the level of permeability is strongly dependent on the type of tumor, the site where the tumor is developing, the state of the tumor and the therapeutic treatment, and significant differences can be observed between human and xenografts tumors [7]. In addition to this, diseases other than cancer do no show any significant vessel permeability, thus making a passive targeting strategy non appropriate. On the other hand, a growing body of evidences support the idea that specific molecules are overexpressed at the surface of a disease
%U http://www.jnanobiotechnology.com/content/6/1/9