Chelating ion-exchange methods for the preparation of no-carrier-added 64Cu

We have developed a method for producing no-carrier-added (64)Cu by using chelating resin bearing iminodiacetic acid groups.

We optimized the conditions for the selective separation of radioactive Cu from Ni and Co using the chelating resin and produced no-carrier-added (64)Cu under the optimized conditions. We analyzed the amounts of the metal ions present in (64)Cu by inductively coupled-plasma mass spectroscopy (ICP-MS) and optical emission spectroscopy (ICP-OES), and performed radiolabeling of monoclonal antibodies in order to investigate the quality of the (64)Cu produced in this study.

Radioactive Cu was separated from Ni and Co with 0.1 and 2 M HCl solutions. The yield of (64)Cu isolated from the (64)NiO target was almost 87%. The radiochemical purity of (64)Cu obtained from different amounts of (64)NiO targets was >99% in all cases. We found that the (64)Cu solution presented extremely low amounts of the metal ions and showed high specific activity (average: 595 GBq/mumol). Moreover, the antibodies were labeled with (64)Cu with a high average efficiency (average: 88%).

We could efficiently separate (64)Cu by using short ion-exchange columns. The chelating ion-exchange method provides a high quality of (64)Cu that is sufficient for the synthesis of (64)Cu-labeled antibodies and medical applications.