Bn₂DT3A, a Chelator for ⁶⁸Ga Positron Emission Tomography: Hydroxide Coordination Increases Biological Stability of [⁶⁸Ga][Ga(Bn₂DT3A)(OH)].

ABSTRACT: The chelator Bn₂DT3A was used to produce a novel ⁶⁸Ga complex for positron emission tomography (PET). Unusually, this system is stabilized by a coordinated hydroxide in aqueous solutions above pH 5, which confers sufficient stability for it to be used for PET. Bn₂DT3A complexes Ga³⁺ in a hexadentate manner, forming a mer-mer complex with log K([Ga(Bn₂DT3A)]) = 18.25. Above pH 5, the hydroxide ion coordinates the Ga³⁺ ion following dissociation of a coordinated amine. Bn₂DT3A radiolabeling displayed a pH-dependent speciation, with [⁶⁸Ga][Ga(Bn₂DT3A)(OH)]^- being formed above pH 5 and efficiently radiolabeled at pH 7.4. Surprisingly, [<

SUBMITTER: Price TW 

PROVIDER: S-EPMC9627565 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature