Precision Atomistic Structures of Actinium-/Radium-/Barium-Doped Lanthanide Nanoconstructs for Radiotherapeutic Applications.

Lanthanide vanadate (LnVO) nanoconstructs have generated considerable interest in radiotherapeutic applications as a medium for nanoscale-targeted drug delivery. For cancer treatment, LnVO nanoconstructs have shown promise in encapsulating and retaining radionuclides that emit alpha-particles. In this work, we examined the structure formation of LnVO nanoconstructs doped with actinium (Ac) and radium (Ra), both experimentally and using large-scale atomistic molecular dynamics simulations. LnVO nanoconstructs were synthesized via a precipitation method in aqueous media. The reaction conditions and elemental compositions were varied to control the structure, fluorescence properties, and size distribution of the LnVO nanoconstructs. LnVO nanoconstructs were characterized by X-ray diffraction, Raman spectroscopy, and fluorescence spectroscopy. Molecular dynamics simulations were performed to obtain a fundamental understanding of the structure-property relationship between radionuclides and LnVO nanoconstructs at the atomic length scale. Molecular dynamics simulations with well-established force field (FF) parameters show that Ra atoms tend to distribute across the nanoconstructs' surface in a broader coordination shell, while the Ac atoms are arranged inside a smaller coordination shell within the nanocluster. The Ba atoms prefer to self-assemble around the surface. These theoretical/simulation predictions of the atomistic structures and an understanding of the relationship between radionuclides and LnVO nanoconstructs at the atomic scale are important because they provide design principles for the future development of nanoconstructs for targeted radionuclide delivery.