Department of Biological Science and Engineering, School of Chemical and Biological Engineering, University of Science and Technology Beijing, 30th Xueyuan Road, Haidian District, Beijing 100083, People’s Republic of China
Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875 People’s Republic of China
A conjugate of 6-hydrazinopyridine-3-carboxylic acid (HYNIC) with aminomethylenediphosphonic acid (AMDP) was synthesized through
a multiple-step reaction. HYNIC–AMDP could be labeled easily and efficiently with 99mTc using N-(2-hydroxy-1,1-bis(hydroxymethyl)ethyl)glycine (tricine) as coligand to form the 99mTc–HYNIC–AMDP complex in high yield (> 95%). Its partition coefficient indicated that it was a good hydrophilic complex. The
biodistribution studies of 99mTc–HYNIC–AMDP in normal ICR mice showed that this complex had high bone uptake and low or negligible accumulation in non-target
organs. As compared with 99mTc–MDP, 99mTc–HYNIC–AMDP had a higher bone uptake and the ratios of bone/blood and bone/muscle at early time after injection, suggesting
that it could be potentially useful for bone imaging at an earlier time after injection according to further investigations
of the biological behavior of this complex.