Figure 3.

In vivo Quenching of Cerenkov Luminescence with Iron Oxide Nanoparticles. The ferumoxytol analog, fluorescently labeled crosslinked iron oxide (Cy5.5-SPIO), or phosphate buffered saline (control) were administered to HT1080 tumor bearing mice. (A) Conventional fluorescent imaging of the Cy5.5 label (external excitation, color-coded in red) was used to follow probe accumulation. Food, green. (B) Following 24 h of nanoparticle uptake, [¹⁸F]-FDG (14.8 MBq) was administered. Representative PET scans show equivalent tumor uptake. (C) The CL scans reveal differences in the light emitted from each tumor. There is greater light output from the PBS control injected mice. B; Bladder. (D) PET quantitation reveals no difference in [18F]-FDG uptake. (E) However, the Cerenkov luminescence detected in the tumors of mice given the Cy5.5-SPIO was significantly attenuated.