Intrinsically 89Zr-labeled Gd2O2S:Eu nanophosphors with high in vivo stability for dual-modality imaging.

Radioluminescence imaging (RLI) employs high energy particles from radioisotope decay for in situ excitation of selected nanophosphors. Co-injection of radiopharmaceuticals and nanophosphors suffers from suboptimal RL efficiency owing to the large separation between the source and the emitter. In addition, vastly different pharmacokinetic profiles of the two further impede the practical applications of this approach. To overcome the above challenges, chelator-free radiolabeled nanophosphors with excellent RL efficiency and dual-modality imaging capabilities have been proposed. Abundant O2- donors on Gd2O2S:Eu could intrinsically chelate oxophilic radionuclide 89Zr with ~80 % labeling yield. Positron emission tomography demonstrated superb long-term radiostability of [89Zr]Gd2O2S:Eu@PEG nanoparticles in vivo, and a conventional optical imaging system was used to study radiouminescence properties of [89Zr]Gd2O2S:Eu@PEG nanoparticles in vitro and in vivo.