Multifunctional GdVO₄:Eu core-shell nanoparticles containing ²²⁵Ac for targeted alpha therapy and molecular imaging

Gadolinium vanadate nanoparticles (NPs) doped with europium, in concentrations between 5-40%, were synthesized via an aqueous route to prove their multimodal imaging functionalities and their performance as radionuclide carriers for targeted alpha therapy. Core-shell Gd_0.8Eu_0.2VO₄ NPs were doped with the α-emitting actinium-225 to assess the in vitro retention of ²²⁵Ac and its decay daughters; francium-221 and bismuth-213. Gd_0.8Eu_0.2VO₄ core-shell NPs were obtained using a precipitation synthesis route having a tetragonal system, a spherical morphology, and a uniform particle size distribution. Gd_0.8Eu_0.2VO₄ core-shell NPs displayed the characteristic intense emission at 618 nm (red) and paramagnetic behavior of Eu and Gd cations, respectively. Partial retention of radionuclides was obtained with Gd_0.8Eu_0.2VO₄ core NPs, while deposition of two nonradioactive Gd_0.8Eu_0.2VO₄ shells significantly decreased the leakage of both ²²⁵Ac and ²²¹Fr. The luminescence and magnetic functionalities as well as radionuclide retention capabilities of Gd_0.8Eu_0.2VO₄ core-shell NPs demonstrate their potential for biomedical applications.