Preparation of Medical Th-Ra Radionuclide Generator Based on SiO@TiO Microspheres.

Ra ( = 3.63 d), an α-emitting radionuclide, holds significant promise in cancer endoradiotherapy. Current Ra-related therapy is still scarce because of the lack of reliable radionuclide supply. The Th-Ra radionuclide generator can undoubtedly introduce continuous and sustainable availability of Ra for advanced nuclear medicine. However, conventional metal oxides for such radionuclide generators manifest suboptimal adsorption capacities for the parent nuclide, primarily attributable to their limited surface area. In this work, core-shell SiO@TiO microspheres were proposed to develop as column materials for the construction of a Th-Ra generator. SiO@TiO microspheres were well prepared and systematically characterized, which has also been demonstrated to have good adsorption capacity to Th and very weak binding affinity toward Ra via simulated chemical separation. Upon introducing Th-containing solution onto the SiO@TiO functional column, a Th-Ra generator with excellent retention of the parent radionuclide and ideal elution efficiency of daughter radionuclide was obtained. The prepared Th-Ra generator can produce Ra with high purity and medical usability in good elution efficiency (98.72%) even over five cycles. To the best of our knowledge, this is the first time that the core-shell mesoporous materials have been applied in a radionuclide generator, which can offer valuable insights for materials chemistry, radiochemical separation, and biological medicine.