Magnetic, fluorescent, and thermo-responsive Fe3O4/rare earth incorporated poly(St-NIPAM) core-shell colloidal nanoparticles in multimodal optical/magnetic resonance imaging probes
Magnetic, fluorescent, and thermo-responsive Fe3O4/rare earth incorporated poly(St-NIPAM) core-shell colloidal nanoparticles in multimodal optical/magnetic resonance imaging probes
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多模态光学/磁共振成像探针中的磁性、荧光和热响应 Fe3O4/稀土掺入聚 (St-NIPAM) 核壳胶体纳米颗粒
DOI：
10.1016/j.biomaterials.2012.11.056
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发表时间：
2013-03-01
期刊：
影响因子：
14
通讯作者：
Chu, Paul K.
中科院分区：
文献类型：
--
作者：
Zhu, Haie;Tao, Juan;Chu, Paul K.
以油酸（OA）和十一碳烯酸钠（NaUA）修饰的Fe 3 O 4纳米粒子为原料，采用两步无种子乳液聚合法制备了具有荧光、超顺磁性和热敏性的多功能纳米胶体粒子。在第一步中，St和NIPAM将NaUA包覆在Fe 3 O 4纳米颗粒的表面，形成Fe 3 O 4/poly（St-NIPAM）纳米颗粒，其作为种子用于在第二步中使Eu（AA）（3）Phen与剩余的St和NIPAM聚合，以形成外部荧光层。核壳复合纳米粒子显示可逆的尺寸变化响应于外部温度刺激。荧光光谱显示Eu 3+的特征发射峰位于594和619 nm，双光子共聚焦扫描激光显微镜（CLSM）观察到明亮的红色荧光。基于MTT法的体外细胞毒性测试表明，该复合材料具有良好的细胞相容性，并且具有顺磁性，最大饱和磁化强度为6.45 emu/g，横向弛豫率（r（2））为411.78 mM（-1）s（-1）。在体内磁共振成像（MRI）研究显示显着的肝脏和脾脏对比度与约86%的相对信号强度降低10分钟后静脉注射的复合物。这些有趣的性质表明，这些纳米载体具有很大的临床潜力，作为多模态光学/MRI探针。(C)2012爱思唯尔有限公司保留所有权利。
Multifunctional colloidal nanoparticles which exhibit fluorescence, superparamagnetism, and thermo-sensitivity are produced by two step seed emulsifier-free emulsion polymerization in the presence of oleic acid (OA) and sodium undecylenate (NaUA) modified Fe3O4 nanoparticles. In the first step, St and NIPAM polymerize the NaUA on the surface of Fe3O4 nanoparticles to form Fe3O4/poly(St-NIPAM) nanoparticles which act as seeds for the polymerization of Eu(AA)(3)Phen with the remaining St and NIPAM in the second step to form an outer fluorescent layer. The core shell composite nanoparticles show reversible dimensional changes in response to external temperature stimuli. Fluorescence spectra acquired from the composites exhibit characteristic emission peaks of Eu3(+) at 594 and 619 nm and vivid red luminescence can be observed by 2-photon confocal scanning laser microscopy (CLSM). In vitro cytotoxicity tests based on the MTT assay demonstrate good cytocompatibility and the composites also possess paramagnetic properties with a maximum saturation magnetization of 6.45 emu/g and high transverse relaxivity rates (r(2)) of 411.78 mM(-1) s(-1). In vivo magnetic resonance imaging (MRI) studies show significant liver and spleen contrast with relative signal intensity reduction of about 86% 10 min after intravenous injection of the composites. These intriguing properties suggest that these nanocarriers have large clinical potential as multimodal optical/MRI probes. (C) 2012 Elsevier Ltd. All rights reserved.