Figure 4

(a) and (b) are in vivo X-ray micrographs of the microvasculature of the leg region of a mouse taken with bare-AuNPs. The smallest detected microvessel has ~8.6 μm diameter, marked by the yellow arrowhead in the inset of (b). Note that the AuNP distribution in the vessels is not continuous. The yellow arrows emphasize that the nanoparticles aggregated in the vessel into large clusters, eventually blocking the flux. (c), (d) and (e) are high resolution X-ray images of vessels in subcutaneous tissue partially coated by bare-AuNPs. Yellow arrowheads indicate agglomerated AuNPs, the white arrow marks an endothelial cell nucleus and the white arrowheads mark erythrocytes in the vessels. Most of the bare-AuNPs adhere to vessel walls and do not interact with erythrocytes. The scale bars are (a) 500 μm, (b) 250 μm (inset 50 μm) (c) and (d) 10 μm and (e) 2.5 μm