Cyclotron Production of High-Specific Activity 55Co and In Vivo Evaluation of the Stability of 55Co Metal-Chelate-Peptide Complexes.
This work describes the production of high-specific activity 55Co and the evaluation of the stability of 55Co-metal-chelate-peptide complexes in vivo. 55Co was produced via the 58Ni(p,α)55Co reaction and purified using anion exchange chromatography with an average recovery of 92% and an average specific activity of 1.96 GBq/μmol. 55Co-DO3A and 55Co-NO2A peptide complexes were radiolabeled at 3.7 MBq/μg and injected into HCT-116 tumor xenografted mice. Positron emission tomography (PET) and biodistribution studies were performed at 24 and 48 hours postinjection and compared to those of 55CoCl2. Both 55Co-metal-chelate complexes demonstrated good in vivo stability by reducing the radiotracers' uptake in the liver by sixfold at 24 hours with ~ 1% ID/g and at 48 hours with ~ 0.5% ID/g and reducing uptake in the heart by fourfold at 24 hours with ~ 0.7% ID/g and sevenfold at 48 hours with ~ 0.35% ID/g. These results support the use of 55Co as a promising new radiotracer for PET imaging of cancer and other diseases.
Tara
T
Mastren
Bernadette V
BV
Marquez
Deborah E
DE
Sultan
Elizabeth
E
Bollinger
Paul
P
Eisenbeis
Tom
T
Voller
Suzanne E
SE
Lapi
D000818:Animals; D002614:Chelating Agents / Q000737:chemistry; D015179:Colorectal Neoplasms / Q000175:diagnosis; D003287:Contrast Media / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D017357:Cyclotrons; D005260:Female; D045325:HCT116 Cells; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D010455:Peptides / Q000737:chemistry*; D049268:Positron-Emission Tomography
D002614:Chelating Agents; D003287:Contrast Media; D056831:Coordination Complexes; D010455:Peptides