ABSTRACT
Copolymer of N-vinylpyrrolidone (VP) with vinylformamide (VFA) and N-vinyliminodiacetic acid (VIDA) was synthesized; its metal-polymer complexes (MPCs) with gallium were obtained. The complexes were characterized by size exclusion chromatography, hydrodynamic and optical methods, scanning electron microscopy, and spectral methods (UV, IR, 1Ð NMR spectroscopy). It was demonstrated that in going from polymer to complex, hydrodynamic parameters of macromolecules change only slightly, although the polymer contains intramolecular Ga(VIDA)2 fragments in its structure. A new method for preparation of MPCs with gallium and gallium-68 radionuclide was suggested. The obtained metal-polymer complex is stable over a wide range of pH values as well as in the histidine challenge reaction. In vivo distribution experiments in intact animals showed high primary accumulation of thegallium-68 MPC in blood with subsequent excretion via urinary tract.
ABSTRACT
The procedure of the directed synthesis of N-vinylpyrrolidone-N-vinylformamide (VP-VFA) copolymers with grafted iminodiacetate (IDA) chelating units is presented. The methods for labelling resulting conjugates with indium-113m were developed. The metal-copolymer conjugates were characterized by different physicochemical methods, including IR and NMR, viscometry, light scattering, and exclusion high-performance liquid chromatography. Parameters of radiochemical synthesis of the conjugates labelled with indium-113m were optimized. It was shown that the VP-VFA-IDA copolymer firmly binds indium-113m both in the acid and alkaline solutions, with pH of the reaction mixture having almost no effect on the complexation. VP-VFA-IDA-In conjugates were found to be unstable in histidine challenge reaction.
