Synthesis of potential 99mTc nitrido tumor imaging disposition in mice

Several cationic or neutral technetium-nitrido complexes of Schiff bases [for which 5-methyl 3-(2-hydroxyphenyl methylene) dithiocarbazate (L1) was a prototype], bis-aminoethanethiol (BAT-TM) and macrocyclic amines were prepared. We report here, the synthesis and isolation of these TcNLn complexes from reaction mixtures by high pressure liquid chromatography or sephadex G25 column. In vivo tissue distribution studies were performed on tumor bearing mice (B16, EMT6, 3LL) after i.v. injection of 10-20 microCi of TcNLn. Although pharmacokinetic differences appeared between the three studied ranges, we did not obtain proof of any particular specificity to tumor tissues. Nevertheless, the complexes were very stable and some of the ligands could be used as chelators after linking side chains or groups inducing specific tumor localization.