FIGURE 6.

Histological examination of α5β1-integrin expression and nanoparticle localization. (a) Fluorescent microscopy images (×200) of conventional immunohistochemistry of 8 μm sections of tumor border stained for α5β1-integrin (green) and endothelium (red), with nuclei counterstained blue. There is prevalent expression of α5β1-integrin throughout the tissue section, both within and outside of the vasculature. (b) The merged images confirm that the nanoparticles colocalized with the angiogenic vasculature, and did not reach the α5β1-integrin expressed by tumor and other cells in the extravascular matrix. Reproduced with permission from the publisher.⁵¹