Cantarelli Irene Xochilt, Pedroni Marco, Piccinelli Fabio, Marzola Pasquina, Boschi Federico, Conti Giamaica, Sbarbati Andrea, Bernardi Paolo, Mosconi Elisa, Perbellini Luigi, Marongiu Laura, Donini Marta, Dusi Stefano, Sorace Lorenzo, Innocenti Claudia, Fantechi Elvira, Sangregorio Claudio, Speghini Adolfo
Dipartimento di Biotecnologie, Università di Verona and INSTM, UdR Verona, Strada le Grazie 15, 37134, Verona, Italy.
Biomater Sci. 2014 Sep 29;2(9):1158-1171. doi: 10.1039/c4bm00119b. Epub 2014 Jun 24.
Water dispersible Gd,Yb,Er and Gd,Yb,Tm doped CaF nanoparticles (NPs) were prepared by one-pot hydrothermal synthesis using citrate ions as capping agents without the need for any post-synthesis reaction. UC emissions are easily observed in the visible and infrared regions upon NIR diode laser excitation at 980 nm. EPR spectroscopy confirms the substitutional nature of the rare-earth doping, while magnetometric studies reveal that the NPs have a useful magnetization. MRI experiments conducted in vivo show that after 40 min from the injection, the NPs localize in the liver and spleen. Electron microscopy images of liver tissue reveal that the NPs are located in the Kupffer cells, although a small amount is also found in the hepatocytes. An excitation with a 980 nm emission on the excised liver and epithelial tissue induces clearly visible UC emission. The local temperature upon 980 nm irradiation was monitored in situ and it was found to increase slowly with the exposure time, maintaining under 1-2 °C for less than 60 second exposure. The NPs show a low toxicity towards cultured HeLa cells and human primary dendritic cells (DCs), and did not induce pro-inflammatory cytokine secretion by cultured human DCs, indicating that the NPs do not cause relevant adverse reactions in immune cells. Therefore, the present NPs are suitable candidates to be efficiently used in surgery applications, where spatial resolution and lack of harmful effects on human health are important issues.
采用柠檬酸盐离子作为封端剂，通过一锅水热合成法制备了水分散性的钆（Gd）、镱（Yb）、铒（Er）和钆（Gd）、镱（Yb）、铥（Tm）掺杂的氟化钙（CaF）纳米颗粒（NPs），无需任何合成后反应。在980nm近红外二极管激光激发下，很容易在可见光和红外区域观察到上转换发光。电子顺磁共振光谱证实了稀土掺杂的取代性质，而磁力测量研究表明这些纳米颗粒具有有用的磁化强度。体内进行的磁共振成像实验表明，注射后40分钟，纳米颗粒定位于肝脏和脾脏。肝脏组织的电子显微镜图像显示，纳米颗粒位于库普弗细胞中，尽管在肝细胞中也发现了少量纳米颗粒。对切除的肝脏和上皮组织进行980nm发射激发，可诱导出清晰可见的上转换发光。原位监测980nm照射时的局部温度，发现其随暴露时间缓慢升高，暴露时间小于60秒时温度保持在1-2°C以下。这些纳米颗粒对培养的人宫颈癌HeLa细胞和人原代树突状细胞（DCs）显示出低毒性，并且不会诱导培养的人DCs分泌促炎细胞因子，这表明纳米颗粒不会在免疫细胞中引起相关不良反应。因此，目前的纳米颗粒是外科手术应用中有效使用的合适候选物，在外科手术应用中，空间分辨率和对人体健康无有害影响是重要问题。
