Experimental studies on imaging of infected site with 99mTc-labeled ciprofloxacin in mice

Background  Bacterial infection can pose a substantial diagnostic dilemma. ^99mTc-labeled ciprofloxacin (CPF) was developed as a biologically active radiopharmaceutical to diagnose infection. In the present research, we studied the biodistribution and imaging properties of infection tracer ^99mTc-CPF in a mouse model of infection.
Methods  CPF was labeled with ^99mTc and the radiochemical purity and labeling rate were measured. A mouse model of infection was established. We then determined the biodistribution of ^99mTc-CPF and conducted the whole body scintigraphy of the animal model.
Results  ^99mTc-Ciprotech was stable for at least 6 hours at room temperature. The labeling rate of CPF by ^99mTc was over 90%. Clearance of radioactivity mainly occurred in the liver and kidney, and the clearance from blood was rapid. Both biodistribution and imaging results showed higher uptake of ^99mTc-CPF at sites of infection. The infectious tissue/normal tissue ratio peak was 4.30 at 4 hours after injection.
Conclusions  ^99mTc-CPF is a sensitive radiopharmaceutical for scintigraphy of infectious lesions and it is easy to prepare.