Shape Matters: IntravitalMicroscopy Reveals SurprisingGeometrical Dependence for Nanoparticles in Tumor Models of Extravasation.

Delivery is one of the most critical obstacles confrontingnanoparticleuse in cancer diagnosis and therapy. For most oncological applications,nanoparticles must extravasate in order to reach tumor cells and performtheir designated task. However, little understanding exists regardingthe effect of nanoparticle shape on extravasation. Herein we use real-timeintravital microscopic imaging to meticulously examine how two differentnanoparticles behave across three different murine tumor models. Thestudy quantitatively demonstrates that high-aspect ratio single-walledcarbon nanotubes (SWNTs) display extravasational behavior surprisinglydifferent from, and counterintuitive to, spherical nanoparticles althoughthe nanoparticles have similar surface coatings, area, and charge.This work quantitatively indicates that nanoscale extravasationalcompetence is highly dependent on nanoparticle geometry and is heterogeneous. [ABSTRACT FROM AUTHOR]