Development of a 68Ge/68Ga Generator System Using Polysaccharide Polymers and Its Application in PET Imaging of Tropical Infectious Diseases

• Published in: ACS omega Vol. 2; no. 4; pp. 1400 - 1407
• Main Authors: Fuchigami, Takeshi, Ono, Hokuto, Oyadomari, Kohta, Iwatake, Mayumi, Hayasaka, Daisuke, Akbari, Masoud, Yui, Katsuyuki, Nishi, Kodai, Kudo, Takashi, Yoshida, Sakura, Haratake, Mamoru, Nakayama, Morio
• Format: Journal Article
• Language: English
• Published: American Chemical Society 30.04.2017
• ISSN: 2470-1343; 2470-1343
• DOI: 10.1021/acsomega.7b00147

Gallium-68 (68Ga) is a positron emitter for clinical positron emission tomography (PET) applications that can be produced by a 68Ge/68Ga generator without cyclotron. However, commercially available 68Ge/68Ga generator systems require multiple steps for the preparation of 68Ga radiopharmaceuticals and are sometimes plagued by metallic impurities in the 68Ga eluent. We developed a 68Ge/68Ga generator system using polysaccharide-based adsorbents and direct application of the generator-eluted 68Ga-citrate to PET imaging of tropical infectious diseases. N-Methylglucamine (MG) as a 68Ge-adsorbing unit (Sepha-MGs) was introduced to a series of Sephadex G-10, G-15, G-25, G-50, and G-75. In the batch method, over 97% of the 68Ge in the solution was adsorbed onto the Sepha-MG series within 15 min. In particular, 68Ge was effectively adsorbed on the Sepha(15)-MG packed columns and 70–80% of the 68Ga was eluted by 1 mL of 0.1 M trisodium citrate with low 68Ge contamination (<0.001%). The chemical form of the generator-eluted 68Ga solution was identified as 68Ga-citrate. In PET studies, affected regions in mice infected with Leishmania and severe fever with thrombocytopenia syndrome virus were clearly visualized using the 68Ga-citrate. Sepha-MGs are useful adsorbents for 68Ge/68Ga generator systems with high 68Ga elution efficiency and minimal 68Ge breakthrough. These results indicated that eluted 68Ga-citrate can be directly used for PET imaging of infectious sites in mice. This novel generator system may be useful for straightforward PET imaging of infection in clinical practice.