Encapsulation and retention of ²²⁵ Ac, ²²³ Ra, ²²⁷ Th, and decay daughters in zircon-type gadolinium vanadate nanoparticles

Journal Article · Wed Sep 16 00:00:00 UTC 2020 · Radiochimica Acta

DOI: https://doi.org/10.1515/ract-2019-3206 · OSTI ID:1734379

Toro-González, Miguel  ^[1]; Dame, Ashley N.  ^[2]; Mirzadeh, Saed  ^[2]; Rojas, Jessika V.  ^[3]

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1. Department of Mechanical and Nuclear Engineering , Virginia Commonwealth University , Richmond , VA , USA, Isotope and Fuel Cycle Technology Division , Oak Ridge National Laboratory , Oak Ridge , TN , USA
2. Isotope and Fuel Cycle Technology Division , Oak Ridge National Laboratory , Oak Ridge , TN , USA
3. Department of Mechanical and Nuclear Engineering , Virginia Commonwealth University , Richmond , VA , USA

Abstract Unwanted targeting of healthy organs caused by the relocation of radionuclides from the target site has been one of the limiting factors in the widespread application of targeted alpha therapy in patient regimens. GdVO ₄ nanoparticles (NPs) were developed as platforms to encapsulate α -emitting radionuclides ²²³ Ra, ²²⁵ Ac, and ²²⁷ Th, and retain their decay daughters at the target site. Polycrystalline GdVO ₄ NPs with different morphologies and a zircon-type tetragonal crystal structure were obtained by precipitation of GdCl ₃ and Na ₃ VO ₄ in aqueous media at room temperature. The ability of GdVO ₄ crystals to host multivalent ions was initially assessed using La, Cs, Bi, Ba, and Pb as surrogates of the radionuclides under investigation. A decrease in Ba encapsulation was obtained after increasing the concentration of surrogate ions, whereas the encapsulation of La cations in GdVO ₄ NPs was quantitative (∼100%). Retention of radionuclides was assessed in vitro by dialyzing the radioactive GdVO ₄ NPs against deionized water. While ²²⁷ Th was quantitatively encapsulated (100%), a partial encapsulation of ²²³ Ra (∼75%) and ²²⁵ Ac (>60%) was observed in GdVO ₄ NPs. The maximum leakage of ²²¹ Fr (1st decay daughter of ²²⁵ Ac) was 55.4 ± 3.6%, whereas for ²²³ Ra (1st decay daughter of ²²⁷ Th) the maximum leakage was 73.0 ± 4.0%. These results show the potential of GdVO ₄ NPs as platforms of α -emitting radionuclides for their application in targeted alpha therapy.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1734379
• Journal Information: Radiochimica Acta, Journal Name: Radiochimica Acta Journal Issue: 12 Vol. 108; ISSN 0033-8230
• Publisher: Walter de Gruyter GmbHCopyright Statement
• Country of Publication: Germany
• Language: English