Synthesis, radiolabeling, and pre-clinical evaluation of [44Sc]Sc-AAZTA conjugate PSMA inhibitor, a new tracer for high-efficiency imaging of prostate cancer.
Eur J Nucl Med Mol Imaging
; 48(8): 2351-2362, 2021 07.
Article
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| MEDLINE
| ID: mdl-33420915
ABSTRACT
PURPOSE:
The aim of this work was to demonstrate the suitability of AAZTA conjugated to PSMA inhibitor (B28110) labeled with scandium-44 as a new PET tracer for diagnostic imaging of prostate cancer.BACKGROUND:
Nowadays, scandium-44 has received significant attention as a potential radionuclide with favorable characteristics for PET applications. A polyaminopolycarboxylate heptadentate ligand based on a 1,4-diazepine scaffold (AAZTA) has been thoroughly studied as chelator for Gd3+ ions for MRI applications. The excellent results of the equilibrium, kinetic, and labeling studies led to a preliminary assessment of the in vitro and in vivo behavior of [44Sc][Sc-(AAZTA)]- and two derivatives, i.e., [44Sc][Sc (CNAAZTA-BSA)] and [44Sc][Sc (CNAAZTA-cRGDfK)].RESULTS:
B28110 was synthesized by hybrid approach, combining solid-phase peptide synthesis (SPPS) and solution chemistry to obtain high purity (97%) product with an overall yield of 9%. Subsequently, the radioactive labeling was performed with scandium-44 produced from natural calcium target in cyclotron, in good radiochemical yields (RCY) under mild condition (pH 4, 298 K). Stability study in human plasma showed good RCP% of [44Sc]Sc-B28110 up to 24 h (94.32%). In vivo PET/MRI imaging on LNCaP tumor-bearing mice showed high tracer accumulation in the tumor regions as early as 20 min post-injection. Ex vivo biodistribution studies confirmed that the accumulation of 44Sc-PSMA-617 was two-fold lower than that of the radiolabeled B28110 probes.CONCLUSIONS:
This work demonstrated the suitability of B28110 for the complexation with scandium-44 at room temperature and the high performance of the resulting new tracer based on AAZTA chelator for the diagnosis of prostate cancer using PET.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Neoplasias de la Próstata
/
Tomografía de Emisión de Positrones
Límite:
Animals
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Humans
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Male
Idioma:
En
Revista:
Eur J Nucl Med Mol Imaging
Asunto de la revista:
MEDICINA NUCLEAR
Año:
2021
Tipo del documento:
Article
País de afiliación:
Italia