[⁶⁸Ga]Ga-Schizokinen, a Potential Radiotracer for Selective Bacterial Infection Imaging.

Area of Science:

• Nuclear Medicine
• Radiochemistry
• Infectious Disease Imaging

Background:

• Siderophores labeled with Gallium-68 (68Ga) are explored for infection-specific imaging.
• Development of novel radiotracers is crucial for early and accurate infection diagnosis.

Purpose of the Study:

• To evaluate gallium-68-labeled schizokinen ([68Ga]Ga-SKN) as a potential radiotracer for bacterial infection imaging.
• To assess the radiolabeling, in vitro characteristics, and in vivo pharmacokinetics of [68Ga]Ga-SKN.

Main Methods:

• Radiolabeling of schizokinen (SKN) with 68Ga.
• In vitro characterization including purity, stability, and bacterial uptake studies.
• In vivo pharmacokinetic and biodistribution studies using positron emission tomography (PET)/computed tomography (CT) in mice.

Main Results:

• [68Ga]Ga-SKN was successfully radiolabeled with high purity (>95%).
• In vitro studies confirmed hydrophilic nature, stability, and specific uptake by bacterial species (E. coli, P. aeruginosa, S. aureus, S. epidermidis), but not fungi.
• In vivo studies in mice showed rapid renal excretion and minimal organ uptake, indicating favorable pharmacokinetics.

Conclusions:

• [68Ga]Ga-SKN exhibits high specificity for bacteria and favorable pharmacokinetic properties.
• Further investigation of [68Ga]Ga-SKN is warranted for its application as a bacteria-specific radiotracer in infection imaging.