SYNTHESIS AND BIODISTRIBUTION OF ~(99) Tc~m-MPAQ

In order to find new Tc-99m complexes for brain per fusion agent, modification of 99 Tc m-MPBDA structure is performed. Tridentate ligand MPAQ is synthesized based on preparation of MPBDA. The products have been characterized by IR, 1H NMR, MS and element analysis. Preparation of “3+1” mixed-ligand complex 99 Tc m-MPAQ is carried out with direct reduction by using Cl -as monodentate ligand. The labeling conditions are optimized. The lipophilicity and stability of 99 Tc m-MPAQ are tested. The results demonstrate that radiochemical purity of 99 Tc m-MPAQ is over 96% with a high stability in aqueous solution and a higher lipophilicity than that of 99 Tc m-MPBDA. Biodistribuion study in ICR mice indicates that although 99 Tc m-MPAQ is no better than 99 Tc m-MPBDA in biological properties, it can cross intact blood brain barrier(1.55 %/g at 5 min post injection) and retain for a certain time(62% remains in brain at 30 min post injection).