Synthesis and biological evaluation of bisphosphonate compound labeled with (99m)Tc(CO)3(+)

Abstract

In this study, radiolabeling of a bisphosphonate, alendronate (Alendronate sodium), was performed with the help of a bifunctional chelating agent. For that purpose, DTPA-NHS (Diethylenetriaminepentaacetic acid dianhydride-N-hydroxysuccinimide) was synthesized with an esterification between DTPA and NHS. Combining the DTPA-NHS ester with alendronate yields the DTPA-Alendronate compound. The structure of synthesized compound was analyzed by (1) H/(13) C/(31) P-NMR and HPLC. After then, the labeling with [(99m) Tc(CO)3 ](+) core of synthesized compound was provided. Performing quality controls of newly synthesized [(99m) Tc(CO)3 -DTPA-Alendronate] complex with thin layer radiochromatography (TLRC) and high-performance liquid radiochromatography (HPLRC), the labeling yield was found as 99%. It was observed that the compound conserves its stability for 24 h in serum media. Biodistribution of the radiolabeled complex was performed on Wistar Albino rats to determine radiopharmaceutical potential of the [(99m) Tc(CO)3 -DTPA-Alendronate] complex. It is thought that the data gained from this study will contribute to the development of complexes with bisphosphonate.

Keywords: DTPA; [99mTc(CO)3]+ core; biodistribution; bisphosphonate.