Efficient Radiosynthesis of ^99mTc-Amygdalin for Tumor Imaging Using a ⁹⁹Mo/^99mTc Generator Based on Alumina Doped...

This study reports the radiosynthesis and biological evaluation of ^99mTc-Amygdalin, using a newly developed chromatographic ⁹⁹Mo/^99mTc generator based on alumina doped with terbium oxide. The prepared sorbent was successfully synthesized and characterized as a structurally stable oxide matrix exhibiting high Mo(VI) sorption capacity (117 mg/g), excellent adsorption selectivity at pH 4, and minimal ⁹⁹Mo breakthrough, enabling the production of high-purity ^99mTc suitable for radiopharmaceutical applications. Amygdalin was efficiently radiolabeled under optimized reductive conditions, achieving radiochemical purity exceeding 90%. In addition, a corresponding rhenium analogue complex was synthesized to support the proposed coordination behavior of the radiocomplex. Biodistribution studies in Ehrlich solid tumor-bearing mice demonstrated rapid blood clearance, favorable systemic distribution, and progressive tumor uptake, reaching 8.5 ± 0.65%ID/g at 120 min post-injection, with target-to-non-target ratios approaching 17 at later time points. The obtained pharmacokinetic profile highlights the potential applicability of ^99mTc-Amygdalin as a promising tumor-targeting radiotracer for diagnostic imaging.