NIR-to-NIR UCL/T1-weighted MR/CT multimodal imaging by NaYbF4∶Tm@NaGdF4∶Yb-PVP upconversion nanoparticles

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2017,（13）
• 页码范围: 903-912
• 页数: 10页
• 语种: 英文

摘要

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.