Gd3+ complex-modified NaLuF4-based upconversion nanophosphors for trimodality imaging of NIR-to-NIR upconversion luminescence, X-Ray computed tomography and magnetic resonance

Multimodality molecular imaging has recently attracted much attention, because it can take advantage of individual imaging modalities by fusing together information from several molecular imaging techniques. Herein, we report a multifunctional lanthanide-based nanoparticle for near-infrared to near-infrared (NIR-to-NIR) upconversion luminescence (UCL), X-ray computed tomography (CT) and T1-enhanced magnetic resonance (MR) trimodality in-vivo imaging. By careful selection of the lanthanide elements, core-shell structured lanthanide-based nanoparticles, NaLuF4:Yb3+,Tm3+@SiO2-GdDTPA nanoparticles (UCNP@SiO2-GdDTPA) have been designed and synthesized. We also prove that the application of UCNP@SiO2-GdDTPA for NIR-to-NIR UCL, CT and MRI multi-modality in-vivo imaging can be established successfully. In addition, the biological toxicity of UCNP@SiO2-GdDTPA is evaluated by the methyl thiazolyl tetrazolium (MTT) assay and histological analysis of viscera sections.