Technetium-99m Tricarbonyl Labeled a Broad-spectrum Quinolone as a Specific Imaging Agent in Infection Diseases

Nuclear medicine imaging has been used to localize infection sites, and efforts have been continued to develop modified infection specific radiopharmaceuticals. In this study gemifloxacin as a broad-spectrum quinolone has been labeled with [^99mTc (CO)₃ (H₂O)₃]⁺ core in order to evaluate its feasibility as an infection imaging agent for in-vivo use. The stability of radioconjugate was checked in human serum at 37 °C and biodistribution was studied in mice. Labeling yield of > 95% was obtained corresponding to a specific activity of 0.14 GBq/μmol. The radioconjugate showed good stability in human serum. Our main achievement was the high accumulation in the infected muscle in mice (T/NT = 2.93 ± 0.3 at 1 h post injection), which may diagnostically be beneficial for differentiate sites of infection from sites of inflammation.