Il sistema [MV(N)(PNP)]2+ (M=Tc-99m, Re-188) nella scintigrafia miocardica e in medicina nucleare molecolare

Recently we have described the synthesis of a new class of asymmetrical nitrido complexes, based on the chemical properties of the substitution labile [Tc(N)X2(PNP)]2+ complex (PNP=aminodiphosphine, X=Cl, OH, H2O), which represent an interesting opportunity in design both perfusion and target-specific radiopharmaceuticals. According to this strategy, the strong electrophylic [Tc(N)(PNP)]2+ moiety efficiently reacts with bifunctional ligands (XY) carrying coordinating atoms π-donors such as S, O or N, to afford asymmetrical nitrido heterocomplexes of the type [Tc(N)(XY)(PNP)]0/+. In this work, studies to demonstrate the effective applicability of this technology to the preparation of perfusion and target-specific agents are reported, through synthesis and biological evaluation of: 1) 99mTc-nitrido complexes as potential myocardial imaging tracers, 2) 99mTc-nitrido complexes as potential target-specific agents, for imaging CCK-B receptor, 3) 188Re-nitrido complexes for therapeutic targeting.