Preparation and Evaluation of New ⁹⁹Tc^m (CO)₃⁺-Labelled Phenanthroline Complexes

The chief requirement to determine if pharmaceuticals may be AD-tracer is that complexes can pass through BBB to enter the brain and have rapid clean from the brain. To develop early diagnose radiopharmaceuticals for Alzheimer’s disease, new phenanthroline complexes 2-(9-anthryl)-1H-imidazo4, 5-f1, 10phenanthroline (aip) and 2-(9-anthryl)-1ethyl-imidazo4, 5-f1, 10phenanthroline (aeip) based on the early research of Ru complexes banding to DNA used for fluescence method were synthesized and labelled by ⁹⁹Tc^mtricarbonyl core. Radiochemical purities of complexes ⁹⁹Tc^m (CO)⁺₃-aip and ⁹⁹Tc^m-(CO)⁺₃-aeip were found to be more than 95% as proved by radioHPLC. Paper electrophoresis show that these complexes are neutral. Biodistribution of these complexes in mice shows the higher early uptakes in brain (2 min,⁹⁹Tc^m (CO)⁺₃-aip: （1.028±0.096）％ID/g; ⁹⁹Tc^m (CO)⁺₃-aeip: （1.191±0.197）％ID/g).