Novel Preparation Methods of (52)Mn for ImmunoPET Imaging

Area of Science:

• Nuclear Medicine
• Radiochemistry
• Bioconjugation

Background:

• Manganese-52 (52)Mn shows potential for positron emission tomography (PET) and manganese-enhanced magnetic resonance imaging (MEMRI).
• Extending (52)Mn applications to bioconjugates requires high-specific-activity (52)Mn suitable for macromolecule labeling.

Purpose of the Study:

• To develop and present a system for the production, purification, and labeling of (52)Mn.
• To demonstrate the applicability of this system for preclinical macromolecule PET imaging using a (52)Mn-DOTA-TRC105 conjugate.

Main Methods:

• Production of (52)Mn via proton irradiation of chromium metal.
• Radiochemical separation using anion exchange chromatography with a semiorganic mobile phase.
• Conjugation and labeling of (52)Mn-DOTA-TRC105 for in vivo PET/CT imaging in a tumor model.

Main Results:

• The production and purification system achieved 62 ± 14% efficiency for (52)Mn recovery with a high separation factor from chromium.
• An effective specific activity of 0.8 GBq/μmol was obtained for (52)Mn.
• In vivo PET/CT imaging showed peak tumor uptake of 18.7 ± 2.7%ID/g at 24 hours post-injection for (52)Mn-DOTA-TRC105.

Conclusions:

• A robust system for producing and purifying high-specific-activity (52)Mn for bioconjugate applications has been established.
• (52)Mn-DOTA-TRC105 demonstrates potential for targeted cancer imaging via PET.
• This work supports the use of (52)Mn in advanced preclinical imaging modalities.