Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5788528 | Science Bulletin | 2017 | 10 Pages |
Multimodal imaging nanoprobes are urgently sought because they can integrate different imaging function into individual nanoplatform and provide more comprehensive and accurate information for the diagnosis of early-stage tumor. Lanthanide-based upconversion nanoparticles (UCNPs) are regarded as promising nanoplatforms to fabricate these probes. Herein, we firstly developed the active core-active shell structured NaYbF4:Tm@NaGdF4:Yb-PVP UCNPs with the average diameter of 13.23 ± 0.96 nm as multimodal imaging probes. These water-dispersible nanoprobes presented excellent near-infrared to near-infrared (NIR-to-NIR) upconversion luminescence (UCL) performance, which is favorable for optical bioimaging due to deeper tissue penetration and autofluorescence reduction. After coated with the NaGdF4:Yb active shell, the UCL emission intensity at 800 nm increased by 7.2 times. These nanoprobes exhibited a desirable longitudinal relaxivity (r1 = 3.58 L/(mmol s)) and strong X-ray attenuation property (58.84 HU L/g). The cytotoxicity assessment, histology analysis and biodistribution study revealed that NaYbF4:Tm@NaGdF4:Yb-PVP UCNPs had relatively low cytotoxicity and negligible organ toxicity. These UCNPs were applied for NIR-to-NIR UCL imaging in vivo. More importantly, the detection of small tumor was successfully achieved under T1-weighted MRI and CT imaging modalities after intravenous injection of these UCNPs. These results revealed that NaYbF4:Tm@NaGdF4:Yb-PVP UCNPs could serve as promising NIR-to-NIR UCL/MRI/CT trimodal imaging probes.
Graphical abstractDownload high-res image (173KB)Download full-size image