美国加州大学伯克利分校Rebecca J. Abergel等研究人员合作开发出可用于PET成像的放射性同位素。2020年12月14日，《自然—化学》杂志在线发表这一研究论文。

研究人员表示，开发靶向性的α射线疗法具有改变疾病治疗方式的潜力。在这些干预措施中，靶向载体用发射α的放射性同位素标记，该放射性同位素将破坏性辐射离散地传递给患病细胞，同时又保留了周围的健康组织。这一方法的广泛使用需要无创成像技术的进步。为此，正电子发射断层扫描（PET）成像已成为最有用的诊断技术之一。不幸的是，许多有前途的α-放射性同位素与PET成像不兼容，例如²²⁵Ac和²²⁷Th。

研究人员通过开发¹³⁴Ce的大规模（Ci规模）生产和纯化方法克服了这一障碍。随后在一个小动物模型中进行的放射性标记和体内PET成像实验表明，¹³⁴Ce（及其¹³⁴La子体）可以用作²²⁵Ac^III（还原的¹³⁴Ce^III）或²²⁷Th^IV（氧化的¹³⁴Ce^IV）的PET成像候选物。

与X射线吸收光谱法结果一起评估这些数据，研究人员证明了如何依赖于严格控制Ce^III/Ce^IV氧化还原对来成功实现这一目的。

附：英文原文

Title: Developing the 134 Ce and 134 La pair as companion positron emission tomography diagnostic isotopes for 225 Ac and 227 Th radiotherapeutics

Author: Tyler A. Bailey, Veronika Mocko, Katherine M. Shield, Dahlia D. An, Andrew C. Akin, Eva R. Birnbaum, Mark Brugh, Jason C. Cooley, Jonathan W. Engle, Michael E. Fassbender, Stacey S. Gauny, Andrew L. Lakes, Francois M. Nortier, Ellen M. OBrien, Sara L. Thiemann, Frankie D. White, Christiaan Vermeulen, Stosh A. Kozimor, Rebecca J. Abergel

Issue&Volume: 2020-12-14

Abstract: Developing targeted α-therapies has the potential to transform how diseases are treated. In these interventions, targeting vectors are labelled with α-emitting radioisotopes that deliver destructive radiation discretely to diseased cells while simultaneously sparing the surrounding healthy tissue. Widespread implementation requires advances in non-invasive imaging technologies that rapidly assay therapeutics. Towards this end, positron emission tomography (PET) imaging has emerged as one of the most informative diagnostic techniques. Unfortunately, many promising α-emitting isotopes such as 225Ac and 227Th are incompatible with PET imaging. Here we overcame this obstacle by developing large-scale (Ci-scale) production and purification methods for 134Ce. Subsequent radiolabelling and in vivo PET imaging experiments in a small animal model demonstrated that 134Ce (and its 134La daughter) could be used as a PET imaging candidate for 225AcIII (with reduced 134CeIII) or 227ThIV (with oxidized 134CeIV). Evaluating these data alongside X-ray absorption spectroscopy results demonstrated how success relied on rigorously controlling the CeIII/CeIV redox couple.

DOI: 10.1038/s41557-020-00598-7

Source: https://www.nature.com/articles/s41557-020-00598-7