Institute for Nuclear Sciences Applied to Health (ICNAS Pharma), Polo das Ciências da Saúde, University of Coimbra, 3000-548 Coimbra, Portugal.
Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), Radiopharmaceutical Research Centre, 077125 Măgurele, Romania.
Molecules. 2023 Jun 9;28(12):4670. doi: 10.3390/molecules28124670.
Antibody and nanobody-based copper-64 radiopharmaceuticals are increasingly being proposed as theranostic tools in multiple human diseases. While the production of copper-64 using solid targets has been established for many years, its use is limited due to the complexity of solid target systems, which are available in only a few cyclotrons worldwide. In contrast, liquid targets, available in virtually in all cyclotrons, constitute a practical and reliable alternative. In this study, we discuss the production, purification, and radiolabeling of antibodies and nanobodies using copper-64 obtained from both solid and liquid targets. Copper-64 production from solid targets was performed on a TR-19 cyclotron with an energy of 11.7 MeV, while liquid target production was obtained by bombarding a nickel-64 solution using an IBA Cyclone Kiube cyclotron with 16.9 MeV on target. Copper-64 was purified from both solid and liquid targets and used to radiolabel NODAGA-Nb, NOTA-Nb, and DOTA-Trastuzumab conjugates. Stability studies were conducted on all radioimmunoconjugates in mouse serum, PBS, and DTPA. Irradiation of the solid target yielded 13.5 ± 0.5 GBq with a beam current of 25 ± 1.2 μA and an irradiation time of 6 h. On the other hand, irradiation of the liquid target resulted in 2.8 ± 1.3 GBq at the end of bombardment (EOB) with a beam current of 54.5 ± 7.8 μA and an irradiation time of 4.1 ± 1.3 h. Successful radiolabeling of NODAGA-Nb, NOTA-Nb, and DOTA-Trastuzumab with copper-64 from both solid and liquid targets was achieved. Specific activities (SA) obtained with the solid target were 0.11, 0.19, and 0.33 MBq/μg for NODAGA-Nb, NOTA-Nb, and DOTA-trastuzumab, respectively. For the liquid target, the corresponding SA values were 0.15, 0.12, and 0.30 MBq/μg. Furthermore, all three radiopharmaceuticals demonstrated stability under the testing conditions. While solid targets have the potential to produce significantly higher activity in a single run, the liquid process offers advantages such as speed, ease of automation, and the feasibility of back-to-back production using a medical cyclotron. In this study, successful radiolabeling of antibodies and nanobodies was achieved using both solid and liquid targets approaches. The radiolabeled compounds exhibited high radiochemical purity and specific activity, rendering them suitable for subsequent in vivo pre-clinical imaging studies.
基于抗体和纳米抗体的铜 64 放射性药物越来越多地被提议作为多种人类疾病的治疗诊断工具。虽然使用固体靶标生产铜 64 已经有多年的历史，但由于固体靶标系统的复杂性，其应用受到限制，因为这些系统仅在全球少数回旋加速器中可用。相比之下，几乎所有回旋加速器都可提供液体靶标，是一种实用且可靠的替代方案。在这项研究中，我们讨论了使用从固体和液体靶标获得的铜 64 生产、纯化和标记抗体和纳米抗体。铜 64 从固体靶标在能量为 11.7 MeV 的 TR-19 回旋加速器上进行生产，而液体靶标生产则是通过用 16.9 MeV 的 IBA Cyclone Kiube 回旋加速器在镍 64 溶液上轰击来获得。铜 64 从固体和液体靶标中纯化，并用于标记 NODAGA-Nb、NOTA-Nb 和 DOTA-曲妥珠单抗缀合物。在小鼠血清、PBS 和 DTPA 中对所有放射性免疫偶联物进行了稳定性研究。固体靶标照射产生了 13.5 ± 0.5 GBq 的放射性活度，束流电流为 25 ± 1.2 μA，照射时间为 6 小时。另一方面，液体靶标照射在束流电流为 54.5 ± 7.8 μA 和照射时间为 4.1 ± 1.3 h 时结束时产生了 2.8 ± 1.3 GBq 的放射性活度。成功地使用从固体和液体靶标获得的铜 64 标记了 NODAGA-Nb、NOTA-Nb 和 DOTA-曲妥珠单抗。使用固体靶标获得的比活度（SA）分别为 NODAGA-Nb、NOTA-Nb 和 DOTA-曲妥珠单抗的 0.11、0.19 和 0.33 MBq/μg。对于液体靶标，相应的 SA 值分别为 0.15、0.12 和 0.30 MBq/μg。此外，所有三种放射性药物在测试条件下均表现出稳定性。虽然固体靶标有可能在单次运行中产生更高的放射性活度，但液体过程具有速度快、易于自动化以及使用医用回旋加速器进行背对背生产的可行性等优势。在这项研究中，成功地使用固体和液体靶标方法标记了抗体和纳米抗体。标记的化合物表现出高放射化学纯度和比活度，使其适合随后的体内临床前成像研究。
