Ciprofloxacin: from infection therapy to molecular imaging

Abstract

Diagnosis of deep-seated bacterial infection remains a serious medical challenge. The situation is becoming more severe with the increasing prevalence of bacteria that are resistant to multiple antibiotic classes. Early efforts to develop imaging agents for infection, such as technetium-99m (Tc) labeled leukocytes, were encouraging, but they failed to differentiate between bacterial infection and sterile inflammation. Other diagnostic techniques, such as ultrasonography, magnetic resonance imaging, and computed tomography, also fail to distinguish between bacterial infection and sterile inflammation. In an attempt to bypass these problems, the potent, broad-spectrum antibiotic ciprofloxacin was labeled with Tc to image bacterial infection. Initial results were encouraging, but excitement declined when controversial results were reported. Subsequent radiolabeling of ciprofloxacin withTc using tricarbonyl and nitrido core, fluorine and rhenium couldn't produce robust infection imaging agent and remained in discussion. The issue of developing a robust probe can be approached by reviewing the broad-spectrum activity of ciprofloxacin, labeling strategies, potential for imaging infection, and structure-activity (specificity) relationships. In this review we discuss ways to accelerate efforts to improve the specificity of ciprofloxacin-based imaging.

Dose-Dependent Internalization and Externalization Integrity Study of Newly Synthesized 99mTc-Thymoquinone Radiopharmaceutical as Cancer Theranostic Agent

“…>90%) is a prerequisite for safe diagnosis and therapy of diseases in oncology set-up. 14 The colloidal particles that exceed in size from 0.22 µm may block the blood capillaries and consequently lead to nonspecific accumulation and radiotoxicity, 15 while the free 99m TcO 4 −1 lead to nonspecific distribution throughout the body making high background activity and made confusion during locating the area of interest. 16 The least radioactive impurities greatly contribute in scintigraphy imaging and therapeutic outcome of newly developed radiopharmaceuticals.…”

Technetium‐99m radiolabeling and biological study of epirubicin for in vivo imaging of multi‐drug‐resistant Staphylococcus aureus infections via single photon emission computed tomography

“…The reduction of 99m Tc depends upon the nature of ligand present in a reaction mixture to make complex with 99m Tc. For example, 99m Tc reduces to +1 in the presence of sestamibi, +3 in the presence of dimercaptosuccinic acid, +4 in the presence of methylene diphosphonate, and +5 in the presence of fluoroquinolones, cephalosporin, or mercaptoacetylglycylglycylglycine (MAG 3 ) or any other bi‐dentate or tetra‐dentate ligands . Direct characterization and structure elucidation of 99m Tc‐labeled radiopharmaceuticals have not yet been reported due to multiple reasons, (a) nano‐molar quantity of radiopharmaceuticals; (b) unable to completely purify and crystalize the radiopharmaceutical; and (c) the presence of free and hydrolyzed 99m Tc which increases with time.…”

The Role of Proteomics in Bacterial Response to Antibiotics

“…Among the group of fluoroquinolones, ciprofloxacin has been the most effective agent against P. aeruginosa [ 110 ]. This antibiotic acts by binding to DNA gyrase and IV topoisomerase in Gram-negative and Gram-positive bacteria, respectively, and inhibiting DNA replication [ 111 ]. This is achieved by stabilization of the DNA-gyrase complex during replication via interaction with the 3-oxo-4-carboxylic acid core ( Figure 2 ) of the antibiotic [ 112 ].…”