Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hong Kong.
Biomaterials. 2012 Dec;33(36):9232-8. doi: 10.1016/j.biomaterials.2012.09.019. Epub 2012 Oct 1.
Herein, a multi-functional nanoprobe of polyethylene glycol (PEG) modified BaGdF₅:Yb/Er upconversion nanoparticles (UCNPs) for tri-modal bioimaging of fluorescence, computed X-ray tomography (CT), and magnetic application is demonstrated for the first time. The PEG-modified BaGdF₅:Yb/Er UCNPs with optimal small size were synthesized by a facile one-pot hydrothermal method. The as-designed single-phase nanoprobe presents near-infrared to visible upconversion emissions in UC fluorescent bioimaging of HeLa cell. Importantly, we have demonstrated in vivo CT images with enhanced signals of spleen of a mouse for 2 h, indicating the UCNPs can be successfully used as CT contrast agent for improving the detection of splenic diseases. In addition, these UCNPs also exhibit excellent intrinsic paramagnetic property which can be also for magnetic imaging. Therefore, our results indicate that a tri-modal nanoprobe served as fluorescent/CT/magnetic bioimaging can be realized using the PEG-modified BaGdF₅:Yb/Er UCNPs with very low cytotoxicity and long circulation time, which would be very useful in a variety of biomedical application fields.
本文首次展示了一种聚乙二醇（PEG）修饰的 BaGdF₅:Yb/Er 上转换纳米粒子（UCNPs）多功能纳米探针，可用于荧光、计算机 X 射线断层扫描（CT）和磁共振三模态生物成像。通过简便的一步水热法合成了具有最佳小尺寸的 PEG 修饰的 BaGdF₅:Yb/Er UCNPs。所设计的单相纳米探针在 HeLa 细胞的 UC 荧光生物成像中呈现近红外到可见的上转换发射。重要的是，我们已经在体内 CT 图像中证明了小鼠脾脏信号增强 2 小时，表明 UCNPs 可以成功用作 CT 造影剂，以提高脾脏疾病的检测效果。此外，这些 UCNPs 还表现出优异的固有顺磁性，也可用于磁共振成像。因此，我们的结果表明，使用具有低细胞毒性和长循环时间的 PEG 修饰的 BaGdF₅:Yb/Er UCNPs 可以实现三模态纳米探针的荧光/CT/磁共振生物成像，这将在各种生物医学应用领域非常有用。
