Development of targeted 161Tb-radiolabeled nanoparticles

Tom Lemaître, Maarten Ooms, Tomas Opsomer, Michiel Van de Voorde, Thomas Cardinaels, Tatjana N. Parac-Vogt

Research outputpeer-review


Objectives: Currently applied cancer therapeutic strategies focus on the non-specific destruction of cells showing uncontrolled growth. This implies that rapidly dividing noncancerous cells may also be damaged. However, there is now a greater emphasis on targeted radionuclide therapies that are designed to damage only the targeted cells. Out of the suitable therapeutic radionuclides, Terbium-161 is gathering more interest in recent years because of its favorable decay properties. It has a half-life of 6.9 days and decays via emission of –-particles (average energy of 154 keV) which have a maximum tissue range of 0.29 mm and linear energy transfer (LET) around 0.32 keV/mm. Additionally, Terbium-161 releases Auger/ conversion electrons during decay, leading to a much higher dose being delivered locally compared to Lutetium-177 which possesses similar decay characteristics but does not emit Auger/conversion electrons. The simultaneous emission of -rays makes Terbium-161 a high-potential theranostic radionuclide. Radionuclides are traditionally transported to the tumor by the means of a chelating molecule coupled to a targeting vector. However, trans-chelation may occur, leading to the potential release of free radionuclides in the organism and hence to the accumulation in non-targeted organs. Furthermore, the dose accumulated in the tumor may be relatively low because of the fast renal clearance of such therapeutic agents. Targeted nano- particles containing the theranostic radionuclide Terbium-161 are thus being developed to address these issues. Methods: Our work focuses on synthesizing core-shell nanoparticles via thermal decomposition of lanthanide salts, their silanization, functionalization with a targeting vector, and finally their characterization. Results: Results show that core-shell NaGdF4@NaGdF4:Tb3+ nano-particles could be produced with a size around 16 nm with a silica coating thickness in the order of a few nanometers. We also showed that modified folic acid could be easily coupled to the surface of silica-coated nanoparticles through the use of the so-called “thiolclick” chemistry. Conclusions: The synthesis involving [161Tb]Tb-doped nanoparticles is currently being carried out to investigate their radiochemical behavior (yield and stability).
Original languageEnglish
Title of host publicationNuclear Medicine and Biology
Subtitle of host publicationAbstracts of the Fourth International Symposium on Technetium and Other Radiometals in Chemistry and Medicine (TERACHEM 2022)
Number of pages1
StatePublished - 1 Dec 2022
Event2022 - TERACHEM: The Fourth International Symposium on Technetium and Other Radiometals in Chemistry and Medicine - Bressanone
Duration: 14 Sep 202217 Sep 2022

Publication series

NameNuclear Medicine and Biology
ISSN (Print)0969-8051
ISSN (Electronic)1872-9614


Conference2022 - TERACHEM

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