GO-Functionalized Large Magnetic Iron Oxide Nanoparticles with Enhanced Colloidal Stability and Hyperthermia Performance

Abstract

Because of their high magnetization and suitable biocompatibility, iron-oxide nanoparticles (IONPs) have been widely employed in various biomedical applications, including magnetic hyperthermia for cancer treatment. In many cases, the colloidal stability requirement will limit the usage of ferromagnetic particles that are usually associated with good magnetic response. To address this challenge, a stable carrier for better colloidal stability regardless of the size or shape of the IONPs while at the same time providing enhanced magnetic hyperthermia heating performance is required. In this work, IONPs of different sizes (4, 8, 20, 45, and 250 nm) were engineered to reside in the graphene oxide (GO) sheet carrier, which were stable in aqueous solution even in the presence of a strong magnetic field. Out of various IONPs sizes, highest specific absorption rate (SAR) value of 5020 W g−1 was obtained with 45 nm GO-IONPs nanocomposites at a frequency and alternating magnetic field of 400 kHz and 32.5 kA m–1, respectively. The calculated intrinsic loss power (ILP) was 12.21 nH m2 kg–1, which is one of the highest ILP values reported for synthesized IONPs to the best of our knowledge. To enhance the excellent colloidal stability in biological environment, the GO-IONPs nanocomposites can be further grafted with polyethylene glycol (PEG) because agglomeration of pristine GO sheets occurs because of adsorption of cations. High ILP values could be well maintained even after PEG coating. The PEGylated 45 nm GO-IONP showed excellent antitumor efficacy in 4T1-tumor model mice by inhibiting tumor progression within a safe dosage range. Overall, the novel nanocomposite in this workPEG-GO-IONPpossesses high hyperthermia performance, excellent colloidal stability in biological environment, and availability of functional groups in GO and can be utilized for tagging in various biomedical applications.

Magnetic Graphene-Based Sheets for Bacteria Capture and Destruction Using a High-Frequency Magnetic Field

“…These unique characteristics provide special sites for immobilization and functionalization by various moieties including polymeric materials such as polyethylenimine [10], chitosan [11], poly(lactic acid) [12,13], and inorganic nanostructures including gold [14], TiO 2 [15], silver nanoparticles [16] and iron oxide nanoparticles [8,14]. Specifically, iron oxide nanoparticles exhibited magnetic characteristics that could be applied to various applications, especially for magnetic fluid hyperthermia [17], magnetic-based bio-separation [18], diagnosis and treatment of infections of bacteria [19], and inductive heating-based magnetic field exposure [20]. Currently, the combination of graphene-based materials and iron oxide nanoparticles have attracted attention due to their potential characteristics as graphene-based materials combined with magnetic nanoparticles [21].…”

Tunable Magnetic Hyperthermia Properties of Pristine and Mildly Reduced Graphene Oxide/Magnetite Nanocomposite Dispersions

“…Relatively few papers [55][56][57] were published on the possible application of graphene oxide/magnetite nanocomposites for magnetic hyperthermia, and only one was found related to the study of the heat production of reduced GO/MNP in an AC magnetic field [58]. Rodrigues et al reported on interesting multifunctional graphene-based magnetic nanocarriers for combined hyperthermia and drug delivery [55].…”

“…Albeit reduced GO/MNP was discussed throughout the paper, none of the broad classes of reducing agents were directly applied, only the possible decomposition (resulting in a loss of oxygen content, which is often misinterpreted as a true chemical reduction) of GO during the co-precipitation of magnetic nanoparticles was assumed. A solvent evaporation method was applied by Sugumaran et al to reside iron oxide nanoparticles of various core sizes in the GO sheet based host [57]. The PEGylated GO/MNP composites with the largest MNP core size showed not only outstanding hyperthermic efficiency with SAR value higher than 5000 W/g, but they exhibited excellent colloid stability as well.…”

Fine tuning and optimization of magnetic hyperthermia treatments using versatile trapezoidal driving-field waveforms

“…26 Optimization of hyperthermia treatments clearly requires, as a necessary condition, optimization of the mechanism of heat release from magnetic NPs, in order to maximize their specic loss power (SLP), 6,[27][28][29] dened as the total power released by the magnetic nanoparticles divided by their total mass. This can be done by either looking for higher-performance magnetic nanomaterials 30,31 and better particle sizes and shapes, 32,33 or trying to devise methods to more efficiently extract the heating power from a given system of nanoparticles. 28 In most in vitro and in vivo applications, the particles are activated by using a radio-frequency (RF) harmonic magnetic eld.…”