Yang Xiaojun, Xiao Qianqian, Niu Caixia, Jin Nan, Ouyang Jin, Xiao Xueyuan, He Dacheng
College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China.
J Mater Chem B. 2013 Jun 7;1(21):2757-2763. doi: 10.1039/c3tb00575e. Epub 2013 Apr 26.
Here we synthesize silica-coated NaYF:Yb/Er nanocomposites with a photosensitizer hypericin covalently bound to silica shells (UCNPs@SiO@hypericin) successfully, exhibiting precise size-control, good water dispersity and excellent biocompatibility. Under near-infrared light (NIR) irradiation, UCNPs convert NIR light to strong green light which agrees well with the absorbance peak of the photosensitizer hypericin, and triggers hypericin to generate singlet oxygen effectively. The cell apoptosis studies by flow cytometry, fluorescence microscope imaging with Annexin V-FITC/PI and caspase-3 western blotting demonstrate that UCNPs@SiO@hypericin-FA displays outstanding performance in the induction of apoptosis of Hela cells and HepG2 cells under NIR light irradiation for a short time. At the same time, UCNPs@SiO@hypericin-FA nanocomposites are proved to exhibit little cytotoxicity by cell viability experiments. By the use of confocal microscopy, cell uptake results show that folate receptor FR(+) cell lines such as Hela cells could internalize more UCNPs@SiO@hypericin-FA than FR(-) cell lines, such as 293T cells, with highly selective cellular uptake. All the results indicate that UCNPs@SiO@hypericin-FA nanocomposites have a promising potential in the application of PDT and other diseases in deep tissues.
在此，我们成功合成了二氧化硅包覆的NaYF:Yb/Er纳米复合材料，其中光敏剂金丝桃素共价结合在二氧化硅壳层上（UCNPs@SiO@金丝桃素），具有精确的尺寸控制、良好的水分散性和优异的生物相容性。在近红外光（NIR）照射下，UCNPs将NIR光转换为与光敏剂金丝桃素的吸收峰高度吻合的强绿光，并有效触发金丝桃素产生活性单线态氧。通过流式细胞术、Annexin V-FITC/PI荧光显微镜成像和caspase-3蛋白质免疫印迹法进行的细胞凋亡研究表明，UCNPs@SiO@金丝桃素-叶酸在近红外光短时间照射下对Hela细胞和HepG2细胞凋亡的诱导方面表现出色。同时，细胞活力实验证明UCNPs@SiO@金丝桃素-叶酸纳米复合材料几乎没有细胞毒性。通过共聚焦显微镜观察，细胞摄取结果显示，叶酸受体FR(+)细胞系如Hela细胞比FR(-)细胞系如293T细胞能摄取更多的UCNPs@SiO@金丝桃素-叶酸，具有高度选择性的细胞摄取。所有结果表明，UCNPs@SiO@金丝桃素-叶酸纳米复合材料在光动力疗法及其他深部组织疾病的应用中具有广阔的前景。
