Preparation and Evaluation of [55Co](II)DTPA for Blood Cell Labeling

摘要

Co-55 (T1/2=17.53 h) was produced by 150 μA irradiation of a natural nickel target by 15 MeV protons and wasseparated from the irradiated target material by two ion exchange chromatography steps and was used for the preparationof [55Co]diethylenetriaminepentacetate ([55Co]DTPA). Optimization studies were performed using Co-57 due to its longerhalf-life. Cobalt-57 (T1/2=271.79 d) was produced by irradiation of a natural nickel target with 150 μA current of 22 MeVprotons. The 57Co was separated from the irradiated target material using a no carrier added method with a radiochemicalyield of > 97%. The 55Co was separated from the irradiated target material using a two step method with a radiochemicalyield of > 95%. Both products were controlled for radionuclide and chemical purity. The solutions of [55Co]complex wereprepared (radiochemical yield>80%) starting with 55CoOAc ligand at room temperature after 30 min. RTLC showed theradiochemical purity of more than 99%. Specific activity was obtained about 9.1 TBq/mmol. The tracer showed to be stablein the final product and in the presence of human serum at 37°C up to 15 h. [55Co]DTPA was successively used in theradiolabeling of red blood cells for PET1diagnostic studies.