Department of Physics and Astronomy, University of Delaware, Newark, DE 19711, USA.
Institute of Nanoscience and Nanotechnology, NCSR Demokritos, 15310, Athens, Greece.
J Mater Chem B. 2022 Jul 6;10(26):4935-4943. doi: 10.1039/d2tb00139j.
Magnetic FeO nanoparticles "decorated" by LAPONITE® nanodisks have been materialized utilizing the Schikorr reaction following a facile approach and tested as mediators of heat for localized magnetic hyperthermia (MH) and as magnetic resonance imaging (MRI) agents. The synthetic protocol involves the interaction between two layered inorganic compounds, ferrous hydroxide, Fe(OH), and the synthetic smectite LAPONITE® clay Na[(SiMgLi)O(OH)], towards the formation of superparamagnetic FeO nanoparticles, which are well decorated by the diamagnetic clay nanodisks. The latter imparts high negative -potential values (up to -34.1 mV) to the particles, which provide stability against flocculation and precipitation, resulting in stable water dispersions. The obtained LAPONITE®-"decorated" FeO nanohybrids were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Mössbauer spectroscopy, dynamic light scattering (DLS) and vibrating sample magnetometry (VSM) at room temperature, revealing superior magnetic hyperthermia performance with specific absorption rate (SAR) values reaching 540 W g (28 kA m, 150 kHz) for the hybrid material with a magnetic loading of 50 wt% FeO/LAPONITE®. Toxicity studies were also performed with human glioblastoma (GBM) cells and human foreskin fibroblasts (HFF), which show negligible to no toxicity. Furthermore, -weighted MR imaging of rodent brain shows that the LAPONITE®-"decorated" FeO nanohybrids predominantly affected the transverse relaxation time of tissue water, which resulted in a signal drop on the MRI -weighted imaging, allowing for imaging of the magnetic nanoparticles.
利用 Schikorr 反应，通过简便的方法实现了被 LAPONITE®纳米盘“修饰”的磁性 FeO 纳米粒子，并将其作为局部磁热疗 (MH) 的热介质和磁共振成像 (MRI) 造影剂进行了测试。该合成方案涉及两种层状无机化合物之间的相互作用，即二价氢氧化铁 Fe(OH)和合成蒙脱石 LAPONITE®粘土 Na[(SiMgLi)O(OH)]，以形成超顺磁性 FeO 纳米粒子，这些纳米粒子被抗磁性粘土纳米盘很好地修饰。后者赋予粒子高达-34.1 mV 的高负电势值，使粒子具有稳定性，防止絮凝和沉淀，从而得到稳定的水分散体。通过粉末 X 射线衍射 (XRD)、透射电子显微镜 (TEM)、穆斯堡尔光谱、动态光散射 (DLS) 和室温下的振动样品磁强计 (VSM)对获得的 LAPONITE®-“修饰”FeO 纳米杂化物进行了表征，结果表明，在磁性负载为 50wt% FeO/LAPONITE®的情况下，该杂化物的比吸收率 (SAR) 值达到 540 W g（28 kA m，150 kHz），具有优异的磁热疗性能。还对人神经胶质瘤 (GBM)细胞和人包皮成纤维细胞 (HFF)进行了毒性研究，结果表明，其毒性可忽略不计或没有毒性。此外，对啮齿动物大脑的-加权磁共振成像表明，LAPONITE®-“修饰”FeO 纳米杂化物主要影响组织水的横向弛豫时间，导致 MRI-加权成像上的信号下降，从而可以对磁性纳米粒子进行成像。
