Kalaiselvan Chandunika R, Thorat Nanasaheb D, Sahu Niroj Kumar
Centre for Nanotechnology Research, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
Medical Science Division, Nuffield Department of Women's & Reproductive Health, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, U.K.
ACS Omega. 2021 Feb 18;6(8):5266-5275. doi: 10.1021/acsomega.0c05382. eCollection 2021 Mar 2.
Ferrites are one of the most studied materials around the globe due to their distinctive biological and magnetic properties. In the same line, anisotropic MnFeO nanoparticles have been explored as a potential candidate possessing excellent magnetic properties, biocompatibility, and strong magnetic resonance imaging (MRI) properties such as 2 relaxivity for magnetic field-guided biomedical applications. The current work reports the synthesis and morphological evolution of MnFeO nanocubes (MNCs) in a hydrothermal process using different volume ratios of water and ethanol. The synthesis protocol was designed to influence the properties of the ferrite nanocubes, for example, the variation in surface tension, dielectric properties, and the ionic character of the solvent, and this has been achieved by adding ethanol into water during the synthesis. Pristine MnFeO is formed with well-defined cubic to irregular cubic shapes with the addition of ethanol, as evidenced from XRD, field emission scanning electron microscopy, and porosity measurements. MNCs have been investigated for magnetic hyperthermia and MRI applications. Well-defined cubic-shaped MNCs with uniform size distribution possessed a high saturation magnetization of 63 emu g and a transverse relaxivity (2) of 216 mM s (Mn + Fe). Furthermore, the colloidal nanocubes showed concentration-dependent hyperthermic response under an alternating magnetic field. The MNCs are biocompatible but advantageously show anticancer activities on breast cancer MCF 7 and MDA-MB-231 cells.
由于其独特的生物学和磁性特性，铁氧体是全球研究最多的材料之一。同样，各向异性的MnFeO纳米颗粒已被探索作为一种潜在的候选材料，具有优异的磁性、生物相容性以及诸如用于磁场引导生物医学应用的纵向弛豫率等强磁共振成像（MRI）特性。当前工作报道了在水热过程中使用不同体积比的水和乙醇合成MnFeO纳米立方体（MNCs）及其形态演变。合成方案旨在影响铁氧体纳米立方体的性质，例如表面张力、介电性质以及溶剂的离子特性的变化，这是通过在合成过程中向水中添加乙醇来实现的。从X射线衍射、场发射扫描电子显微镜和孔隙率测量结果可以看出，添加乙醇后形成了具有明确立方到不规则立方形状的原始MnFeO。已对MNCs进行了磁热疗和MRI应用研究。具有均匀尺寸分布的明确立方形状的MNCs具有63 emu g的高饱和磁化强度和216 mM s（Mn + Fe）的横向弛豫率（纵向弛豫率）。此外，胶体纳米立方体在交变磁场下表现出浓度依赖性的热疗响应。MNCs具有生物相容性，但有利的是对乳腺癌MCF 7和MDA - MB - 231细胞显示出抗癌活性。
