PMC

HUVECs were incubated with 3.2 μm oxidized silicon microparticles at a ratio of 1:10 (cell/particle) for 15-60 min in a serum-free medium. Uptake of particles by HUVEC cells was imaged by SEM. (Reproduced with permission from (). Courtesy of Elsevier)

Left: Smooth, tight endothelial cell monolayer covering the luminal surface of a normal blood vessel. Right: Disorganized endothelium of a tumor blood vessel. A gap is apparent at an open endothelial cell juncture. (Reproduced with permission from (). Courtesy of Elsevier)

(a) The 1^st stage porous silicon loaded with siRNA nanoparticles travels in the circulation, and attaches to the tumor vascular endothelium. (b) The 1^st stage particle releases 2^nd stage carrier nanoparticles through the vascular endothelium into tumor interstitium where they are taken up by tumor cells. (c) Possible routes of siRNA entry into tumor cells.

Mice bearing human SKOV3ip1 orthotopic ovarian tumors were dosed once with MSV/ePhA2 siRNA. (A) Knockdown of EphA2 gene expression was confirmed by Western blot analysis. (B) Densitometric analysis to normalize EphA2 expression by β-actin. (C) Immunohistochemical analysis of EphA2 expression in tumor tissues. (Reproduced with permission from (). Courtesy of American Association for Cancer Research)