Kamimura Masao, Matsumoto Taiki, Suyari Satoru, Umezawa Masakazu, Soga Kohei
Department of Materials Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
J Mater Chem B. 2017 Mar 14;5(10):1917-1925. doi: 10.1039/c7tb00070g. Epub 2017 Feb 9.
A novel nanothermometer based on over-1000 nm (OTN) near-infrared (NIR) emission of rare-earth doped ceramic nanophosphors (RED-CNPs) was developed for temperature measurement in deep tissue. Hexagonal-phase β-NaYF nanoparticles co-doped with Yb, Ho, and Er (NaYF:Yb,Ho,Er NPs) were synthesized and used as a nanothermometer. The NaYF:Yb,Ho,Er NPs displayed two OTN-NIR emission peaks in the second (NIR-II) (at 1150 nm of Ho) and third (NIR-III) (at 1550 nm of Er) biological window regions under NIR (980 nm) excitation in the first (NIR-I) biological window region. Oleic acid (OA) capped NaYF:Yb,Ho,Er NPs were dispersed in non-polar media, i.e., cyclohexane, and showed a temperature-dependent intensity ratio of the emission peaks of Ho and Er (I/I). The temperature-dependent I/I of the OA-NaYF:Yb,Ho,Er NPs was also evident through imitation tissue. The surfaces of the NaYF:Yb,Ho,Er NPs were modified with a poly(ethylene glycol) (PEG)-based block copolymer. The PEGylated NaYF:Yb,Ho,Er NPs were dispersed in water and emitted strong NIR-II and III emissions under NIR-I excitation. The PEGylated NaYF:Yb,Ho,Er NPs were injected into mice via the tail vein, and the OTN-NIR emissions of the PEGylated NaYF:Yb,Ho,Er NPs from the mouse blood vessels were clearly observed using an OTN-NIR fluorescence in vivo imaging system. In a polar media, water, the I/I of PEGylated NaYF:Yb,Ho,Er NPs was inversely related to the temperature. In both non-polar and polar media, the I/I values of the NaYF:Yb,Ho,Er NPs were almost linearly dependent on the temperature. The obtained NaYF:Yb,Ho,Er NPs are promising as a novel fluorescent nanothermometer for deep tissue.
一种基于稀土掺杂陶瓷纳米磷光体（RED-CNPs）超过1000纳米（OTN）近红外（NIR）发射的新型纳米温度计被开发用于深部组织温度测量。合成了共掺杂Yb、Ho和Er的六方相β-NaYF纳米颗粒（NaYF:Yb,Ho,Er NPs）并将其用作纳米温度计。在近红外（980纳米）激发下，NaYF:Yb,Ho,Er NPs在第一（NIR-I）生物窗口区域的第二（NIR-II）（Ho的1150纳米处）和第三（NIR-III）（Er的1550纳米处）生物窗口区域显示出两个OTN-NIR发射峰。油酸（OA）包覆的NaYF:Yb,Ho,Er NPs分散在非极性介质环己烷中，并显示出Ho和Er发射峰的强度比（I/I）与温度相关。通过模拟组织，OA-NaYF:Yb,Ho,Er NPs的I/I与温度的相关性也很明显。NaYF:Yb,Ho,Er NPs的表面用聚乙二醇（PEG）基嵌段共聚物进行了修饰。聚乙二醇化的NaYF:Yb,Ho,Er NPs分散在水中，并在NIR-I激发下发射出强烈的NIR-II和III发射。聚乙二醇化的NaYF:Yb,Ho,Er NPs通过尾静脉注射到小鼠体内，使用OTN-NIR荧光体内成像系统可以清楚地观察到小鼠血管中聚乙二醇化的NaYF:Yb,Ho,Er NPs的OTN-NIR发射。在极性介质水中，聚乙二醇化的NaYF:Yb,Ho,Er NPs的I/I与温度呈负相关。在非极性和极性介质中，NaYF:Yb,Ho,Er NPs的I/I值几乎与温度呈线性相关。所获得的NaYF:Yb,Ho,Er NPs有望成为一种用于深部组织的新型荧光纳米温度计。
