ИСТИНА

Radioisotopes of Bismuth, Copper and Rare earth elements (REE) are characterized by suitable nuclear properties for diagnostic or therapeutic purposes. Chemical binding of their cations is very important for target delivery to lesions. In our work we systematically investigate new azacrown-ethers and bispidine ligands as potential chelators to be used in radiopharmaceuticals. We evaluate influence of introduction of various functional moieties such as carboxylic, pyridine, picolinic on complexation ability towards cations with different coordination properties. For complexation constants’ determination different titration and radiochemical techniques are used. Afterwards the leading complexes are tested for in vitro serum stability and in vivo behavior. By this time it is shown that hard REE cations can be bound only by ligands possessing carboxylic arms. Unfortunately the determined constants logK(ML)=5-8 are still not high enough for their application with REE in radiopharmacy. However complexation of cations with lower hardness as Bi3+ and Cu2+ is strong enough for further tests (logK(ML)=14-21). It was shown that selected best complexes BiL and CuL from investigated series are stable in presence of serum proteins.