The radioactive 103Pd and 109Pd palladium bipyridyl–bisphosphonate complexes for radionuclide therapy of bone metastatic tumor cells

Experimental data collected for the preparation of the manuscript "The radioactive 103Pd and 109Pd palladium bipyridyl–bisphosphonate complexes for radionuclide therapy of bone metastatic tumor cells"The publication describes the synthesis and preliminary biological studies of complexes containing the palladium radioisotopes 103Pd and 109Pd, which are considered potential candidates for cancer therapy due to their emission of Auger electrons. In the study, complexes with bipyridyl ligands and alendronate molecule were synthesized. The obtained compounds showed good stability and a strong affinity for hydroxyapatite, the primary mineral component of bone tissue.Biological studies showed that the radioactive palladium complexes exhibited high cytotoxicity toward human prostate cancer (DU-145) and HER2-positive ovarian cancer (SKOV-3) cell lines. The study also examined the behavior of the decay products in the complexes. After the decay of 109Pd, the daughter isotope 109mAg was released from the complex, whereas the decay product of 103Pd, 103mRh, remained retained in the complex structure. This retention was related to the presence of delocalized electrons in the aromatic bipyridyl ligand, which inhibits the release of rhodium. Based on these observations, the authors suggest that generator systems based on the 109Pd/109mAg and 103Pd/103mRh pairs may represent a promising concept for further development of radionuclide-based therapeutic strategies