Figure 6b:

Principle of a nanoparticulate CT contrast agent. (a) Schematic representation of the contrast-generating iodinated compound of the nanoparticle CT contrast agent N1177 containing three iodine (I) atoms (red). (b) Electron microscopy image of N1177. The nanoparticles are suspensions of crystalline iodinated compound, combined with biocompatible surfactants to prevent aggregation and stabilize nanoparticle size. Shown are electron-dense iodinated granules coated by polymers appearing as negative prints after staining with a solution of uranyl acetate. Nanoparticles have various sizes and shapes. Scale bar = 100 nm. (Adapted and reprinted, with permission, from reference 72.)