Department of Chemistry, Physics, and Atmospheric Science, Jackson State University, Jackson, Mississippi 39217, United States.
School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, Mississippi 39406, United States.
Langmuir. 2021 Jan 26;37(3):1279-1287. doi: 10.1021/acs.langmuir.0c03314. Epub 2021 Jan 12.
The synthesis of highly water-dispersible iron oxide nanoparticles with surface functional groups and precisely controlled sizes is essential for biomedical application. In this paper, we report a one-pot strategy for versatile surface functionalization. The iron oxide nanoparticles are first synthesized by thermal decomposition of iron(III) acetylacetonate (Fe(acac)) in diethylene glycol (DEG), and their surfaces are modified by adding the surface ligands at the end of the reaction. The size of iron oxide nanoparticles can be precisely controlled in nanometer scale by continuous growth. This facile synthesis method enables the surface modification with different coating materials such as dopamine (DOPA), polyethylene glycol with thiol end group (thiol-PEG), and poly(acrylic acid) (PAA) onto the iron oxide nanoparticles, introducing new surface functionalities for future biomedical application. From transmission electron microscopy (TEM) and X-ray diffraction (XRD), the morphology and crystal structure are not changed during surface functionalization. The attachment of surface ligands is studied by Fourier transform infrared spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). The surface functional groups are confirmed by X-ray Photoelectron Spectroscopy (XPS). In correlation with the change of hydrodynamic size, PAA coated nanoparticles are found to exhibit outstanding stability in aqueous solution. Furthermore, we demonstrate that the functional groups are available for conjugating with other molecules such as fluorescent dye, showing potential biological applications. Lastly, the magnetic resonance phantom studies demonstrate that iron oxide nanoparticles with PAA coating can be used as and dual-modality contrast agents. Both and relaxivities significantly increase after surface functionalization with PAA, indicating improved sensitivity.
具有表面官能团和精确控制尺寸的高水分散氧化铁纳米粒子的合成对于生物医学应用至关重要。在本文中，我们报告了一种多功能表面功能化的一锅策略。首先通过二乙二醇（DEG）中乙酰丙酮铁（Fe（acac））的热分解合成氧化铁纳米粒子，并在反应结束时添加表面配体来修饰其表面。通过连续生长可以精确控制氧化铁纳米粒子的尺寸在纳米范围内。这种简便的合成方法能够用不同的涂层材料（如多巴胺（DOPA）、带有巯基末端的聚乙二醇（thiol-PEG）和聚丙烯酸（PAA））对氧化铁纳米粒子进行表面改性，为未来的生物医学应用引入新的表面功能。从透射电子显微镜（TEM）和 X 射线衍射（XRD）来看，在表面功能化过程中形态和晶体结构没有改变。通过傅里叶变换红外光谱（FTIR）和热重分析（TGA）研究表面配体的附着。通过 X 射线光电子能谱（XPS）确认表面官能团。与水动力尺寸的变化相关，发现 PAA 涂层纳米粒子在水溶液中表现出出色的稳定性。此外，我们证明了这些官能团可用于与其他分子（如荧光染料）结合，显示出潜在的生物应用。最后，磁共振造影剂研究表明，具有 PAA 涂层的氧化铁纳米粒子可用作 T1 和 T2 双模态造影剂。表面功能化后 T1 和 T2 弛豫率显著增加，表明灵敏度提高。
