Annamalaisamy Geeva Prasanth, Lyczko Monika, Bilewicz Aleksander
Center of Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology Dorodna 16 Warsaw 03-195 Poland.
RSC Adv. 2025 Jun 3;15(23):18501-18511. doi: 10.1039/d5ra02172c. eCollection 2025 May 29.
Two radioisotopes of palladium, Pd and Pd, are considered promising candidates for therapeutic applications because they emit Auger electrons, which are known for their effectiveness in targeting and destroying cancerous cells. We synthesized complexes of Pd and Pd with two bipyridyl and one alendronate molecule. The complexes demonstrated stability and a strong affinity for the surface of hydroxyapatite grains, the main mineral component of bones. Radioactive complexes show significantly higher cytotoxicity against human prostate (DU 145) and ovarian Her2 positive (SKOV-3) cancer cell lines compared to trastuzumab labeled with the Auger electron emitter I and cisplatin. The biological studies showed that both Pd, a pure Auger electron emitter, and Pd, which emits both beta and Auger electrons, demonstrate high cytotoxicity. Furthermore, it was observed that in the tested complexes, Ag, a decay product of Pd, was released from the complex following the decay of Pd. In contrast, Rh, a decay product of Pd, remained within the structure of the complex. The release of Rh from the Pd complex is inhibited by the presence of delocalized electrons in the aromatic bipyridyl ligand. The concept of using a Pd/Ag and Pd/Rh generator encourages further exploration of this treatment strategy.
钯的两种放射性同位素，钯-103和钯-109，被认为是治疗应用的有前景的候选物，因为它们发射俄歇电子，而俄歇电子以其在靶向和破坏癌细胞方面的有效性而闻名。我们合成了钯-103和钯-109与两个联吡啶和一个阿仑膦酸盐分子的配合物。这些配合物表现出稳定性以及对羟基磷灰石颗粒表面（骨骼的主要矿物质成分）的强亲和力。与用俄歇电子发射体碘-125标记的曲妥珠单抗和顺铂相比，放射性配合物对人前列腺（DU 145）和卵巢Her2阳性（SKOV-3）癌细胞系显示出显著更高的细胞毒性。生物学研究表明，作为纯俄歇电子发射体的钯-103和既发射β电子又发射俄歇电子的钯-109都表现出高细胞毒性。此外，观察到在测试的配合物中，钯-103的衰变产物银在钯-103衰变后从配合物中释放出来。相反，钯-109的衰变产物铑保留在配合物结构内。芳族联吡啶配体中离域电子的存在抑制了铑从钯-109配合物中的释放。使用钯-银和钯-铑发生器的概念鼓励进一步探索这种治疗策略。
