scholarly journals Magnetic Properties and SAR for Gadolinium-Doped Iron Oxide Nanoparticles Prepared by Hydrothermal Method

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1153
Author(s):  
Heba Kahil ◽  
Ahmed Faramawy ◽  
Hesham El-Sayed ◽  
Adel Abdel-Sattar
Keyword(s):  
Iron Oxide ◽  
Hydrothermal Method ◽  
Iron Oxide Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Pure Iron ◽  
Xrd Analysis ◽  
Solubility Limit ◽  
Great Promise ◽  
Oxide Nanoparticles ◽  
Pure Iron Oxide

This study is an attempt to produce gadolinium-doped iron oxide nanoparticles for the purpose of utilization in magnetic fluid hyperthermia (MFH). Six gadolinium-doped iron oxide samples with varying gadolinium contents ( were prepared using the hydrothermal method and high vapor pressure to incorporate gadolinium ions in the iron oxide structure. The samples were indexed as , with varying from 0.0 to 0.1. The results reveal that gadolinium ions have a low solubility limit in the iron oxide lattice (x = 0.04). The addition of gadolinium caused distortion in the produced maghemite phase and formation of other phases. Based on X-ray diffraction (XRD) analysis and photoelectron spectroscopy (XPS), it was observed that gadolinium mostly crystalized as gadolinium hydroxide, for gadolinium concentrations above the solubility limit. The measured magnetization values are consistent with the formed phases. The saturation magnetization values for all gadolinium-doped samples are lower than the undoped sample. The specific absorption rate (SAR) for the pure iron oxide samples was measured. Sample GdIO/0.04, pure iron oxide doped with gadolinium, showed the highest potential to produce heat at a frequency of 198 kHz. Therefore, the sample is considered to hold great promise as an MFH agent.

scholarly journals Biocompatible Magnetic Fluids of Co-Doped Iron Oxide Nanoparticles with Tunable Magnetic Properties

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1019 ◽  
Author(s):  
Silvio Dutz ◽  
Norbert Buske ◽  
Joachim Landers ◽  
Christine Gräfe ◽  
Heiko Wende ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Pure Iron ◽  
Cobalt Ferrite ◽  
Oxide Nanoparticles ◽  
Iron Oxide Particles ◽  
Heating Performance ◽  
Co Doped ◽  
Pure Iron Oxide

Magnetite (Fe3O4) particles with a diameter around 10 nm have a very low coercivity (Hc) and relative remnant magnetization (Mr/Ms), which is unfavorable for magnetic fluid hyperthermia. In contrast, cobalt ferrite (CoFe2O4) particles of the same size have a very high Hc and Mr/Ms, which is magnetically too hard to obtain suitable specific heating power (SHP) in hyperthermia. For the optimization of the magnetic properties, the Fe2+ ions of magnetite were substituted by Co2+ step by step, which results in a Co doped iron oxide inverse spinel with an adjustable Fe2+ substitution degree in the full range of pure iron oxide up to pure cobalt ferrite. The obtained magnetic nanoparticles were characterized regarding their structural and magnetic properties as well as their cell toxicity. The pure iron oxide particles showed an average size of 8 nm, which increased up to 12 nm for the cobalt ferrite. For ferrofluids containing the prepared particles, only a limited dependence of Hc and Mr/Ms on the Co content in the particles was found, which confirms a stable dispersion of the particles within the ferrofluid. For dry particles, a strong correlation between the Co content and the resulting Hc and Mr/Ms was detected. For small substitution degrees, only a slight increase in Hc was found for the increasing Co content, whereas for a substitution of more than 10% of the Fe atoms by Co, a strong linear increase in Hc and Mr/Ms was obtained. Mössbauer spectroscopy revealed predominantly Fe3+ in all samples, while also verifying an ordered magnetic structure with a low to moderate surface spin canting. Relative spectral areas of Mössbauer subspectra indicated a mainly random distribution of Co2+ ions rather than the more pronounced octahedral site-preference of bulk CoFe2O4. Cell vitality studies confirmed no increased toxicity of the Co-doped iron oxide nanoparticles compared to the pure iron oxide ones. Magnetic heating performance was confirmed to be a function of coercivity as well. The here presented non-toxic magnetic nanoparticle system enables the tuning of the magnetic properties of the particles without a remarkable change in particles size. The found heating performance is suitable for magnetic hyperthermia application.

scholarly journals Macrophage-Laden Gold Nanoflowers Embedded with Ultrasmall Iron Oxide Nanoparticles for Enhanced Dual-Mode CT/MR Imaging of Tumors

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 995
Author(s):  
Yucheng Peng ◽  
Xiaomeng Wang ◽  
Yue Wang ◽  
Yue Gao ◽  
Rui Guo ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Mr Imaging ◽  
Iron Oxide Nanoparticles ◽  
Colloidal Stability ◽  
Pamam Dendrimer ◽  
Great Promise ◽  
Oxide Nanoparticles ◽  
Dual Mode ◽  
Gold Nanoflowers ◽  
Average Size

The design of multimodal imaging nanoplatforms with improved tumor accumulation represents a major trend in the current development of precision nanomedicine. To this end, we report herein the preparation of macrophage (MA)-laden gold nanoflowers (NFs) embedded with ultrasmall iron oxide nanoparticles (USIO NPs) for enhanced dual-mode computed tomography (CT) and magnetic resonance (MR) imaging of tumors. In this work, generation 5 poly(amidoamine) (G5 PAMAM) dendrimer-stabilized gold (Au) NPs were conjugated with sodium citrate-stabilized USIO NPs to form hybrid seed particles for the subsequent growth of Au nanoflowers (NFs). Afterwards, the remaining terminal amines of dendrimers were acetylated to form the dendrimer-stabilized Fe3O4/Au NFs (for short, Fe3O4/Au DSNFs). The acquired Fe3O4/Au DSNFs possess an average size around 90 nm, display a high r1 relaxivity (1.22 mM−1 s−1), and exhibit good colloidal stability and cytocompatibility. The created hybrid DSNFs can be loaded within MAs without producing any toxicity to the cells. Through the mediation of MAs with a tumor homing and immune evasion property, the Fe3O4/Au DSNFs can be delivered to tumors more efficiently than those without MAs after intravenous injection, thus significantly improving the MR/CT imaging performance of tumors. The developed MA-mediated delivery system may hold great promise for enhanced tumor delivery of other contrast agents or nanomedicines for precision cancer nanomedicine applications.

Size distribution of magnetic iron oxide nanoparticles using Warren–Averbach XRD analysis

2012 ◽  
Vol 73 (7) ◽  
pp. 867-872 ◽  
Author(s):  
S. Mahadevan ◽  
S.P. Behera ◽  
G. Gnanaprakash ◽  
T. Jayakumar ◽  
J. Philip ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Size Distribution ◽  
Iron Oxide Nanoparticles ◽  
Xrd Analysis ◽  
Oxide Nanoparticles ◽  
Magnetic Iron Oxide Nanoparticles ◽  
Magnetic Iron Oxide

Synthesis of iron oxide nanoparticles in a continuous flow spiral microreactor and Corning® advanced flow™ reactor

2018 ◽  
Vol 7 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Prashant L. Suryawanshi ◽  
Shirish H. Sonawane ◽  
Bharat A. Bhanvase ◽  
Muthupandian Ashokkumar ◽  
Makarand S. Pimplapure ◽  
...  
Keyword(s):  
Particle Size ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Continuous Flow ◽  
Xrd Analysis ◽  
Resonance Spectroscopy ◽  
Oxide Nanoparticles ◽  
Flow Rates ◽  
Nanometer Size Range ◽  
Co Precipitation

AbstractIn the present work, synthesis of iron oxide nanoparticles (NPs) using continuous flow microreactor (MR) and advanced flow™ reactor (AFR™) has been investigated with evaluation of the efficacy of the two types of MRs. Effect of the different operating parameters on the characteristics of the obtained NPs has also been investigated. The synthesis of iron oxide NPs was based on the co-precipitation and reduction reactions using iron (III) nitrate precursor and sodium hydroxide as reducing agents. The iron oxide NPs were characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, and X-ray diffraction (XRD) analysis. The mean particle size of the obtained NPs was less than 10 nm at all flow rates (over the range of 20−60 ml/h) in the case of spiral MR, while, in the case of AFR™, the particle size of NPs was below 20 nm with no specific trend observed with the operating flow rates. The XRD and TEM analyses of iron oxide NPs confirmed the crystalline nature and nanometer size range, respectively. Further, magnetic properties of the synthesized iron oxide NPs were studied using electron spin resonance spectroscopy; the resonance absorption peak shows theg-factor values as 2.055 and 2.034 corresponding to the magnetic fields of 319.28 and 322.59 mT for MR and AFR™, respectively.

Synthesis and Characterization of Iron Oxide Nanoparticles

2014 ◽  
pp. 89-107 ◽  
Author(s):  
John M. Melnyczuk ◽  
Soubantika Palchoudhury
Keyword(s):  
Magnetic Properties ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Surface Coating ◽  
Good Control ◽  
Decomposition Methods ◽  
Great Promise ◽  
Oxide Nanoparticles ◽  
Co Precipitation

Iron oxide nanoparticles show great promise in bio-applications like drug delivery, magnetic resonance imaging, and hyperthermia. This is because the size of these magnetic nanoparticles is comparable to biomolecules and the particles can be removed via normal iron metabolic pathways. These nanoparticles are also attractive for industrial separations and catalysis because they can be magnetically recovered. However, the size, morphology, and surface coating of the iron oxide nanoparticles greatly affect their magnetic properties and biocompatibility. Therefore, nanoparticles with tunable characteristics are desirable. This chapter elaborates the synthesis techniques for the formation of iron oxide nanoparticles with good control over reproducibility, surface and magnetic properties, and morphology. The well-known co-precipitation and thermal decomposition methods are detailed in this chapter. The surface modification routes and characterization of these nanoparticles are also discussed. The chapter will be particularly useful for engineering/science graduate students and/or faculty interested in synthesizing iron oxide nanoparticles for specific research applications.

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