Synthesis and Physicochemical Properties of Cefepime Derivatives Suitable for Labeling with Gallium-68

Abstract

Bone and soft tissue infections are potentially life-threatening and require immediate and intensive treatment. However, there is still no single diagnostic method that can reliably confirm or rule out such conditions. Imaging with radiopharmaceuticals (i.e., scintigraphy) is a powerful diagnostic tool in the management of patients with infectious or inflammatory diseases. In this work, a new and efficient way to modify the thiazole ring of the cefepime molecule has been proposed and experimentally verified. The developed organic synthesis routes allow for the coupling of the appropriate complexing ligand of the gallium-68 radionuclide with cefepime. The new NODAGA-Glu-CFM conjugate was radiolabeled with gallium-68 with a high yield and showed full stability in human serum. In addition, the [68Ga]Ga-NODAGA-Glu-CFM radioconjugate was hydrophilic and positively charged. Therefore, on the basis of these results, the [68Ga]Ga-NODAGA-Glu-CFM radioconjugate might be considered as a new promising radioconjugate for the diagnosis of bacterial infections.