Trapp Svenja, Santoso Albert, Hounat Yassine, Paulssen Elisabeth, van Ommen J Ruud, van Steijn Volkert, de Kruijff Robin M
Department of Radiation Science and Technology, Delft University of Technology, 2629 JB, Delft, the Netherlands.
Department of Chemical Engineering, Delft University of Technology, 2629 HZ, Delft, the Netherlands.
Sci Rep. 2024 Dec 2;14(1):29988. doi: 10.1038/s41598-024-81177-5.
Separating medical radionuclides from their targets is one of the most critical steps in radiopharmaceutical production. Among many separation methods, solvent extraction has a lot of potential due to its simplicity, high selectivity, and high efficiency. Especially with the rise of polydimethylsiloxane (PDMS) microfluidic chips, this extraction process can take place in a simple and reproducible chip platform continuously and automatically. Furthermore, the microfluidic chips can be coated with metal-oxide nano-layers, increasing their resistance against the employed organic solvents. We fabricated such chips and demonstrated a parallel flow at a considerably large range of flow rates using the aqueous and organic solutions commonly used in medical radionuclide extraction. In our following case study for the separation of Ac-225 from radium with the chelator di(2-ethylhexyl)phosphoric acid (D2EHPA), a remarkable extraction efficiency of 97.1 % ± 1.5 % was reached within 1.8 seconds of contact time, while maintaining a near perfect phase separation of the aqueous and organic solutions. This method has the potential to enable automation of solvent extraction and faster target recycling, and serves, therefore, as a proof-of-concept for the applicability of microfluidic chip solvent extraction of (medical) radionuclides.
从靶标中分离医用放射性核素是放射性药物生产中最关键的步骤之一。在众多分离方法中，溶剂萃取因其操作简单、选择性高和效率高而具有很大潜力。特别是随着聚二甲基硅氧烷（PDMS）微流控芯片的兴起，这种萃取过程可以在一个简单且可重复的芯片平台上连续自动地进行。此外，微流控芯片可以涂覆金属氧化物纳米层，提高其对所用有机溶剂的耐受性。我们制造了这样的芯片，并使用医用放射性核素萃取中常用的水溶液和有机溶液，在相当大的流速范围内展示了平行流。在我们接下来用螯合剂二（2-乙基己基）磷酸（D2EHPA）从镭中分离Ac-225的案例研究中，在1.8秒的接触时间内达到了97.1%±1.5%的显著萃取效率，同时保持了水相和有机相溶液近乎完美的相分离。这种方法有可能实现溶剂萃取的自动化和更快的靶标循环利用，因此可作为微流控芯片溶剂萃取（医用）放射性核素适用性的概念验证。
