Radiosynthesis and Animal Studies of 111In-DTPA-bis-alendronate Complex
Keywords: Alendronate, In-111, Biodistribution, DTPA-conjugate, Imaging.
AbstractPurpose- In order to develop new bone imaging agent based on bisphosphonatemoiety, an alendronate based complex was designed and prepared in this study.Methods- A DTPA-conjugated bis-alendronate analog (DTPA-bis-ALN) 3, wasprepared for possible bone imaging after radiolabeling with 111In. RadiolabeledDTPA-bis-ALN complex was prepared starting radionuclide in chloride form andDTPA-bis-ALN in 30-90 min at 50-60°C in acetate buffer followed by solid phasepurification on C18 Sep-Pak cartridge. RTLC was used for radiochemical puritydetermination followed by log P determination, stability studies, hydroxyl apatite tests and biodistribution studies in normal rats and imaging.Results- Specific activity 1.1-1.3 TBq/mmmol was obtained for 111In-complex. The log Ps was calculated 0.48 for the complex consistent with water soluble complexes followed by stability test. The biodistribution of the labeled compound in normalrats demonstrated activity uptake in kidneys.Conclusions- The anionic property of poly-dentate complex led to renal excretion instead of bone accumulation. These data showed that the developed complexes are not suitable agents for bone imaging as expected.
How to Cite
Fakhari A, R. Jalilian A, Shafiee Ardestani M, Johari Deha F, Mirzaie M, Moradkhan S, Khalaj A. Radiosynthesis and Animal Studies of 111In-DTPA-bis-alendronate Complex. FBT. 2(3):163-71.