Wang Fei, Xu Lijun, Zhang Yang, Petrenko Valery A, Liu Aihua
Institute for Biosensing, and College of Chemistry and Chemical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071, China.
J Mater Chem B. 2017 Nov 7;5(41):8209-8218. doi: 10.1039/c7tb02004j. Epub 2017 Oct 11.
Magnetic nanoparticles with superparamagnetic properties have provided a versatile platform for constructing multifunctional nanostructures, which show great promise in tumor-targeted multimodal imaging and non-invasive therapy. Herein, we first systematically investigated the effect of crystalline water in the reactants on the assembly of primary FeO nanocrystals prepared by a solvothermal method. The presence of water would hinder the formation of monodisperse FeO nanocrystals. The regular spheric FeO nanoclusters with high saturated magnetization values and superparamagnetism can be synthesized with anhydrous reactants and sodium citrate as a stabilizer. Furthermore, the monodisperse FeO nanoclusters were used as cores and coated with fluorescent dye molecule covalently-doped silica layers, on which carbohydrate-stabilized gold nanoparticles could be assembled. FeO core@dye/SiO@Au shell nanocomposites were gradually formed by several cycles of a reduction process in the growth solution. The resultant ferroferric oxide@dye/silica@Au nanoshells exhibited good biocompatibility, an excellent T-weighted relaxation rate, a strong fluorescence signal and tunable near IR surface plasmon resonance (SPR) spectra. Finally, colorectal cancer cell SW620-specific phage fusion proteins (fusion-pVIII) were conjugated onto the surface of gold nanoshells, which exhibited a maximal SPR peak of 774 nm and effectively achieved the photothermal ablation of tumor cells selectively with 808 nm laser irradiation for 10 min in a light intensity of 3 W cm. Additionally, the prepared bio-nanocomposite showed good T-weighted magnetic resonance imaging (MRI). Therefore, the FeO@dye/SiO@Au@fusion-pVIII nanocomposites were successfully prepared and applied for targeted optical imaging and the targeted photothermal therapy of cancer cells. The prepared bio-nanocomposites can be potentially applied as ideal contrast agents for tumors in MRI.
具有超顺磁性的磁性纳米颗粒为构建多功能纳米结构提供了一个通用平台，在肿瘤靶向多模态成像和非侵入性治疗方面显示出巨大潜力。在此，我们首先系统研究了反应物中的结晶水对溶剂热法制备的初级FeO纳米晶体组装的影响。水的存在会阻碍单分散FeO纳米晶体的形成。以无水反应物和柠檬酸钠为稳定剂，可以合成具有高饱和磁化值和超顺磁性的规则球形FeO纳米团簇。此外，将单分散的FeO纳米团簇用作核心，并共价包覆荧光染料分子掺杂的二氧化硅层，在其上可以组装碳水化合物稳定的金纳米颗粒。通过在生长溶液中进行几个还原过程循环，逐渐形成FeO核@染料/SiO@Au壳纳米复合材料。所得的四氧化三铁@染料/二氧化硅@金纳米壳表现出良好的生物相容性、优异的T加权弛豫率、强荧光信号和可调谐的近红外表面等离子体共振（SPR）光谱。最后，将结肠癌细胞SW620特异性噬菌体融合蛋白（融合-pVIII）缀合到金纳米壳表面，其SPR最大峰为774 nm，在3 W cm的光强下用808 nm激光照射10分钟，有效地实现了对肿瘤细胞的选择性光热消融。此外，所制备的生物纳米复合材料表现出良好的T加权磁共振成像（MRI）。因此，成功制备了FeO@染料/SiO@Au@融合-pVIII纳米复合材料，并将其应用于癌细胞的靶向光学成像和靶向光热治疗。所制备的生物纳米复合材料有可能作为MRI中理想的肿瘤造影剂。
