Department of Chemical and Biomolecular Engineering, National University of Singapore, Kent Ridge, Singapore 119260, Singapore.
Biomaterials. 2011 Mar;32(8):2166-73. doi: 10.1016/j.biomaterials.2010.11.042. Epub 2010 Dec 13.
Ligand-mediated magnetic resonance (MR) contrast agents would be highly desirable for cancer diagnosis. In the present study, nanoparticles of Fe₃O₄ core with fluorescent SiO₂ shell were synthesized and grafted with hyperbranched polyglycerol (HPG-grafted Fe₃O₄@SiO₂ nanoparticles). These nanoparticles have a hydrodynamic diameter of 47.0 ± 4.0 nm, and are very stable in aqueous solution as well as in cell culture medium. Numerous surface hydroxyl groups of these nanoparticles were conjugated with folic acid by a thiol 'click' reaction. The successful covalent attachment of folic acid on the nanoparticles was confirmed by FTIR and XPS analyses. Both MR imaging and fluorescence microscopy show significant preferential uptake of the folic acid-conjugated polyglycerol-grafted Fe₃O₄@SiO₂ (FA-HPG-grafted Fe₃O₄@SiO₂) nanoparticles by human ovarian carcinoma cells (SKOV-3) as compared to macrophages and fibroblasts. Such nanoparticles can potentially be used to provide real-time imaging in ovarian cancer resection.
配体介导的磁共振（MR）对比剂将非常有利于癌症诊断。在本研究中，合成了具有荧光 SiO₂壳的 Fe₃O₄核纳米粒子，并接枝了超支化聚甘油（HPG-grafted Fe₃O₄@SiO₂纳米粒子）。这些纳米粒子的水动力学直径为 47.0±4.0nm，在水溶液和细胞培养液中非常稳定。这些纳米粒子的大量表面羟基通过硫醇“点击”反应与叶酸偶联。FTIR 和 XPS 分析证实了叶酸成功地共价连接到纳米粒子上。与巨噬细胞和成纤维细胞相比，MR 成像和荧光显微镜均显示出叶酸偶联的聚甘油接枝的 Fe₃O₄@SiO₂（FA-HPG-grafted Fe₃O₄@SiO₂）纳米粒子对人卵巢癌细胞（SKOV-3）的摄取具有明显的偏好。这些纳米粒子有望用于卵巢癌切除术中的实时成像。
