title: Search of ligands suitable for212Pb/212Bi in vivo generators.
abstract: The short half-life of212Bi and213Bi limits the application of these radionuclides in α radionuclide therapy. The labeling of biomolecules with212Pb (mother nuclide of212Bi) instead of212Bi or213Bi has the advantage of obtaining a conjugate with a half-life of 10.6 h, compared with of 60 min for212Bi or 46 min for213Bi. Previous attempts to prepare a potential in vivo generator with212Pb complexed by the DOTA chelator failed, because about 36 % of Bi was reported to escape as a result of the radioactive decay [Formula: see text]. Herein, we report studies on the stability of the212Pb complexes with eight selected polydentate ligands, which demonstrate high affinity for 3+ metal cations. From the ligand studied DOTP and BAPTA show a sufficient212Pb labeling yields but only212Pb-DOTP complex is stable in isotonic solution of sodium chloride making this way radioactivity level of released212Bi is below the limit of detection. It should be emphasized that the DOTP complex is stable only in the case when the concentration of free DOTP exceeds 10-4M.
authors.affiliation: Centre for Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, Dorodna 16 03-195, Warszawa, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Bartoś
authors.affiliation: Centre for Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, Dorodna 16 03-195, Warszawa, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Lyczko
authors.affiliation: Centre for Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, Dorodna 16 03-195, Warszawa, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Kasperek
authors.affiliation: Centre for Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, Dorodna 16 03-195, Warszawa, Poland.
authors.forename: Seweryn
authors.initials: S
authors.lastname: Krajewski
authors.affiliation: Centre for Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, Dorodna 16 03-195, Warszawa, Poland.
authors.forename: Aleksander
authors.initials: A
authors.lastname: Bilewicz
keywords: 212Bi; 212Pb; In vivo generator; Polyaminipolycarboxylate ligands