Synthesis, radiochemical and biological characteristics of 99mTc-8-hydroxy-7-substituted quinoline complex: a novel agent for infection imaging

Abstract

2,2-[(8-hydroxyquinolin-7-yl)methylazanediyl] diacetic acid (HQMADA) was synthesized via reaction of 8-hydroxyquinoline with iminodiacetic acid in presence of paraformaldehyde with a yield of 27%. The obtained compound was well characterized via different analytical techniques. Labeling of the synthesized compound with technetium-99m in pertechnetate form (99mTcO4-) in the presence of stannous chloride dihydrate was carried out via chelation reaction. The reaction parameters that affect the labeling yield such as HQMADA concentration, stannous chloride dihydrate concentration, pH of the reaction mixture, and reaction time were studied to optimize the labeling conditions. Maximum radiochemical yield of 99mTc-HQMADA complex (91.9%) was obtained by using 1.5 mg HQMADA, 50 lg SnCl2_2H2O, pH 8 and 30 min reaction time. Biodistribution studies in mice were carried out in experimentally induced infection in the left thigh using E. coli. 99mTc-HQMADA complex showed higher uptake (T/NT = 5.5 ± 0.3) in the infectious lesion than the commercially available 99mTc-ciprofloxacin (T/NT = 3.8 ±0.8). Biodistribution studies for 99mTc-HQMADA complex in Albino mice bearing septic and aseptic inflammation models showed that 99mTc-HQMADA complex able to differentiate between septic and aseptic inflammation.