%0 Journal Article
%T Radiolabeling of ciprofloxacin with Tc-99m and evaluation of its biological activity for infectious foci scintigraphy
%A Seyedeh Fatemeh Mirshojaei
%A Mostafa Gandomkar
%A Reza Najafi
%A Mohamad Mazidi
%J Iranian Journal of Nuclear Medicine
%D 2010
%I 
%X Introduction: Radiolabeled antibiotics are being used for the specific diagnosis of infection by exploiting their specific binding properties to the bacterial components, thereby making it possible to differentiate infection from sterile lesions. Ciprofloxacin is a fluoroquinolone antibiotic which is active against both gram-positive and gram-negative bacteria. It inhibits the DNA gyrase enzyme and thus interferes with the strand cutting and releasing function during DNA replication. 99mTc-ciprofloxacin is the most widely used infection imaging agent. The aim of this work was radiolabeling of 99mTc-ciprofloxacin and evaluation of its stability and biological activity, which make it able to identify a septic focus (E-coli) in the experimental infection model in mice. Methods: Antibiotic was reconstituted with 99mTc at room temperature and incubation time of 15 min. The kit stability and affinity to human serum was challenged for 24 hours and its in vitro binding to bacteria was assessed. Biodistribution and accumulation of labeled compound in staphylococcus aureus infected mice were studied using Scintigraphic methods and ex vivo counting. Results: Radiolabeling was performed at high specific activities, and radiochemical purity was >90¡À4 %. The stability of radiolabeled peptide in human serum was excellent. In-vitro studies showed 75 % of radioactivity was bound to bacteria. After injection into mice with a bacterial infection, removing from the circulation occurred mainly by biliary-renal clearance and site of infection was rapidly detected within 30 min. The ratio of infected muscle to non-infected muscle is 3.2 and 1.8, 1h and 4 hours post injection. Conclusion: 99mTc-ciprofloxacin is a stable, reproducible and safe preparation with high labeling efficiency having specific accumulation in bacteria. It showed favorable radiochemical and biological characteristics which permitted detection of the infection with optimal visualization.
%K Ciprofloxacin
%K Radiolabeling
%K Infection imaging
%U http://journals.tums.ac.ir/PdfMed.aspx?pdf_med=/upload_files/pdf/16805.pdf&manuscript_id=16805