Interaction Of Magnetic Nanoparticles Research Articles

Formation of a ‘protein corona’ on the Fe3O4@SiO2 nanoparticles surface

The patterns of interaction of the nanoparticles surface with protein components of biosystems have been studied on the example of the interaction of magnetic nanoparticles of the core–shell structure with albumin. Data on particle sizes and their spectra in the visible region in the presence of different quantity of protein have been obtained and analyzed by sorption, spectral and dynamic light scattering methods and albumin sorption isotherms in various media. The formation of the ordered protein monolayer (so-called ‘hard corona’) with subsequent forming of the multilayer of a different structure (‘soft corona’) has been experimentally shown; it demonstrates that it is possible to computationally distinguish between mono- and multi-layer using data from sorption experiments.

Inversion of magnetic diameter distribution of magnetic fluids under high and low temperatures

The magnetic diameter is a crucial factor affecting the magnetic properties of magnetic fluids. The magnetic diameter distribution can be estimated based on the magnetic properties. However, the magnetic dipole interaction of magnetic nanoparticles (MNPs) and the variation of the magnetic diameter with temperature have received relatively little attention in previous research. Hence, this research proposes the AP-MMF1-L method to inverse the magnetic diameter which considers the magnetic dipole interaction and derives the magnetic diameter at different temperatures. Firstly, the AP-MMF1-L uses the least square method between the first-order modified mean-field Langevin function (MMF1-L) and the measured magnetization curve as the objective function. Meanwhile, the hybrid Artificial bee colony-particle swarm (AP) optimization algorithm is introduced to inverse the optimal magnetic diameter distribution. Secondly, the hydrodynamic diameter distribution experimental values are compared with the theoretical values, demonstrating the AP-MMF1-L method obtains accurate inversion results of the magnetic diameter distribution when compared to other models. Finally, the arithmetic mean of the magnetic diameter at different temperatures is investigated, revealing a decreasing trend as the temperature rises, approximately following a linear distribution. The AP-MMF1-L provides a novel and effective tool for accurately determining the magnetic diameter of the MNPs across various temperatures.

Impact of Anisotropy and Electromagnetic Modified Effect on Fluid Mobility in Reservoir Sandstone

The oil and gas sector faces challenges in optimizing oil recovery from reservoirs due to trapped oil due to interfacial tension and surface forces. Characterizing anisotropic dielectric properties is crucial. The petroleum business is quickly changing, and a massive advancement in the application of nanotechnology in this field is envisaged. Because magnetic nanoparticles (MNP) are solid, tiny, and adsorb at the oil-water interface, they might be helpful. The interaction of MNP with electromagnetic waves appears to be capable of altering interfacial tension, which will boost oil recovery. The interaction of an oscillating B-field of electromagnetic waves with magnetic domains causes energy dissipation due to a shift in magnetic anisotropy from the easy axis of magnetization. The use of anisotropy energy in mobilizing oil in a porous media has recently been investigated. BaTiO3 nanoparticles (NPs) were synthesized for this purpose, and their influence on oil mobility under electromagnetic waves (EM) was studied. The anisotropy energy was computed and determined to be 7.34kJ/mol. Under EM, the easy axis magnetization of BaTiO3 nanoparticles oscillates and changes direction continually, facilitating oil mobilization in the porous media. The EM findings for reducing interfacial tension (IFT) between oil and water ranged from 4.5mN/m to 0.89mN/m. Under EM, it was discovered that BaTiO3 nanoparticles might lower IFT by roughly 60%. The IFT must be small enough to allow oil flow during mobilization. The simulation findings demonstrate that the adsorption energy of n-hexane on the surface of hematite has a 47.9% lower energy value than water. With a 115.4% percentage difference, the stress autocorrelation function of n-hexane with hematite is greater than that of water.

Synergistic immunomodulatory effect in macrophages mediated by magnetic nanoparticles modified with miRNAs.

In this work, we describe the synthesis of magnetic nanoparticles composed of a maghemite core (MNP) and three different coatings (dextran, D-MNP; carboxymethyldextran, CMD-MNP; and dimercaptosuccinic acid, DMSA-MNP). Their interactions with red blood cells, plasma proteins, and macrophages were also assessed. CMD-MNP was selected for its good biosafety profile and for promoting a pro-inflammatory response in macrophages, which was associated with the nature of the coating. Thus, we proposed a smart miRNA delivery system using CMD-MNP as a carrier for cancer immunotherapy applications. Particularly, we prove that CMD-MNP-miRNA155 and CMD-MNP-miRNA125b nanoparticles can display a pro-inflammatory response in human macrophages by increasing the expression of CD80 and the levels of TNF-α and IL-6. Hence, our proposed miRNA-delivery nanosystem can be exploited as a new immunotherapeutic tool based on magnetic nanoparticles.

Dynamic magnetic response of ferrofluids under a static electric field

Magnetic nanoparticles in a non-polar ferrofluid can reassemble in external electric fields. The resulting electric field-driven structural changes in ferrofluids are expected to influence the magnetic response of ferrofluids to an alternating magnetic field. Hence, it should be possible to control the magnetic susceptibility of ferrofluids by electric forces. To address the problem of a possible electro-magnetic coupling, a low-frequency alternating current magnetic susceptibility of a ferrofluid based on insulating oil and iron oxide nanoparticles is measured under a static electric field. The electric field is generated by applying a voltage on a pair of electrodes embracing the ferrofluid and acts parallel and perpendicular to the probing alternating magnetic field. The susceptibility is measured simultaneously with the ferrofluid's temperature and a leakage current. A noticeable susceptibility decrease with increasing voltage is found. The susceptibility decrease is partially caused by the temperature increase. Based on theoretical calculations, it is found that the detected temperature increase cannot be the only reason for the measured susceptibility decrease. Other mechanisms resulting from magnetic nanoparticle interactions with the electric field (nanoparticle trapping due to dielectrophoresis, electric field-induced nanoparticle aggregation) must contribute to the susceptibility drop in a static electric field.

Магнитные наночастицы, полученные электрофизическими методами: фокус на биомедицинские приложения

This work describes the possibility of fabrication of the large batches of magnetic nanoparticles using electrophysical methods of electric explosion of the wire, laser target evaporation and spark discharge. Bioapplications of nanoparticles require the production of magnetic materials in the form of stabilized aqueous suspensions or hydrogels with magnetic fillers; therefore, some details of the synthesis of these materials and their certification are discussed. The peculiarities of interaction of magnetic nanoparticles with biological systems, the problem of biocompatibility, the possibility of using ferrogel substrates for the needs of cell technologies and regenerative medicine, as well as implication of biomimetics in the development of magnetic biosensors are considered. The results of the analysis of a number of different biological experiments carried out with suspensions of various types, obtained based on the same batch of MNPs are presented. An analysis of examples of magnetic biodetection and existing theoretical approaches will make it possible to assess the prospects of this scientific direction for the creation of highly sensitive thin film sensors based on the giant magnetoimpedance effect for biomedical applications

Controllability of ferrofluids’ dielectric spectrum by means of external electric forces

A broadband dielectric response of ferrofluids can be effectively controlled by application of an external magnetic field. The interaction of magnetic nanoparticles with magnetic forces and the resulting structural changes in the ferrofluids may tune their dielectric spectra. In this paper, we present an experimental study on the controllability of a dielectric spectrum of Mn-Zn ferrite transformer oil-based ferrofluid by means of a static electric field generated by a direct current (DC) bias voltage. Two experimental configurations of the DC bias voltage are applied. The spectrum of a complex permittivity measured in the frequency range from 1 mHz up to 200 kHz is firstly studied under an internal DC bias voltage applied on the electrodes of a measuring capacitor. Then, the sensitivity of the dielectric spectrum to the external DC bias voltage applied on an external pair of electrodes outside the measuring capacitor is investigated. It is found that the increasing internal DC bias voltage significantly shifts the whole dielectric spectrum to lower frequencies and gives rise to higher permittivity values. The external DC bias voltage is remarkably less capable of such tuning. The obtained dielectric spectra are described by a fitting function composed of Havriliak–Negami and conductivity terms. The fitting parameters are compared in the analysis of the two DC bias voltage effects. An interfacial polarization on the nanoparticles is considered to dominate the dielectric spectrum. The aggregation of nanoparticles due to the induced electric polarization and the acting electric forces is discussed as a primary reason of the changes in the dielectric spectra. The DC bias voltage-tunable dielectric spectrum thus complements the controllability of ferrofluids by external forces and may open a new avenue of research and applications in electrical engineering.

In vitro Biological Tests as the First Tools To Validate Magnetic Nanotheranostics for Colorectal Cancer Models.

Colorectal cancer (CRC) remains a leading cause of cancer death. Nanotechnology has focused on reaching more effective treatments. In this concern, magnetic nanoparticles (MNPs) have been studied for a wide range of biomedical applications related to CRC, such as diagnostic imaging, drug delivery and thermal therapy. However, limited research is currently found in the open literature that refers to nanosystems combining all these mentioned areas (theranostics). When developing nanosystems intended as theranostics applied to CRC, possible variations between patients must be considered. Therefore, multiple in vitro assays are required as guidance for future preclinical and clinical trials. The objective of this contribution is to evaluate the available and recent literature regarding the interactions of MNP and CRC models, aiming to critically analyze the information given by the commonly used assays and evaluate the data provided by each one with a view to implementing this novel technology in CRC diagnostics and therapy.

Interaction of Magnetic Nanoparticles in Cells of Human Breast Adenocarcinoma (MCF-7)

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Magnetic nanoparticles for the measurement of cell mechanics using force-induced remnant magnetization spectroscopy.

Cell mechanics is a crucial indicator of cell function and health, controlling important biological activities such as cell adhesion, migration, and differentiation, wound healing, and tissue integrity. Particularly, the adhesion of cancer cells to the extracellular matrix significantly contributes to cancer progression and metastasis. Here we develop magnetic nanoparticle-based force-induced remnant magnetization spectroscopy (FIRMS) as a novel method to measure cell adhesion force. Before FIRMS experiments, interactions of magnetic nanoparticles (MNPs) with cells were investigated from a cell mechanics perspective. Subsequently adhesion force for three commonly used cancer cell lines was quantified by FIRMS. Our results indicated that the application of MNPs produced indistinguishable effects on cell viability and cell mechanical properties under experimental conditions for the FIRMS method. Then cell adhesion force was obtained, which provides force information on different cancer cell types. Our work demonstrates that MNP-based FIRMS can be applied to probe cell adhesion force and offer an alternate means for understanding cell mechanics.

The effect of magnetization of natural rubber latex-coated magnetite nanoparticles on shear wave dispersion magneto-motive ultrasound

The shear wave dispersion magneto-motive ultrasound (SDMMUS) method was recently developed to analyze the mechanical properties of a viscoelastic medium. This technique is based on the interaction of magnetic nanoparticles (MNPs) with an external magnetic field to generate a shear wave within the medium labeled with MNPs. The propagation of this wave provides information about the viscoelastic properties of the medium. In a previous work by Arsalani et al (2018), magnetite NPs were synthesized by a co-precipitation method and coated with natural rubber latex (NRL). In order to investigate the effect of NRL on the size and magnetization of MNPs, varying amounts of NRL (zero, 100 µl, and 800 µl of a stock solution of NRL) were used during the synthesis process. The results showed that MNPs prepared with 800 µl of NRL, named as MNPs-800NRL, had the smallest size and highest magnetization. In the present paper, the main objective is to investigate whether MNPs-800NRL, having the highest magnetization, is also the best option for SDMMUS experiments among others. All experiments were performed using gelatin tissue-mimicking phantoms labeled with the aforementioned MNPs. The two factors of core size and magnetization were considered, and based on the observed results, the effect of magnetization was more prominent than that of the core size on the induced displacements. MNPs coated with a thicker NRL shell, having the highest magnetization value, enhanced the sensitivity and the signal to noise ratio in SDMMUS. Various concentrations of these optimized MNPs were also examined, to investigate the lowest possible concentration for observing shear waves in the SDMMUS technique.

Bubble Magnetometry of Nanoparticle Heterogeneity and Interaction.

Bubbles have a rich history as transducers in particle-physics experiments. In a solid-state analogue, we use bubble domains in nanomagnetic films to measure magnetic nanoparticles. This technique can determine the magnetic orientation of a single nanoparticle in a fraction of a second and generate a full hysteresis loop in a few seconds. We achieve this high throughput by tuning the nanomagnetic properties of the films, including the Dzyaloshinskii-Moriya interaction, in an application of topological protection from the skyrmion state to a nanoparticle sensor. We develop the technique on nickel-iron nanorods and iron-oxide nanoparticles, which delineate a wide range of properties and applications. Bubble magnetometry enables precise statistical analysis of the magnetic hysteresis of dispersed nanoparticles, and direct measurement of a transition from superparamagnetic behavior as single nanoparticles to collective behavior in nanoscale agglomerates. These results demonstrate a practical capability for measuring the heterogeneity and interaction of magnetic nanoparticles.

Gallate-induced nanoparticle uptake by tumor cells: Structure-activity relationships.

How nanoparticles interact with biological systems determines whether they can be used in theranostic applications. It has been demonstrated that tea catechins, may enhance interactions of magnetic nanoparticles (MNPs) with tumor cells and the subsequent cellular internalization of MNPs. As part of the chemical structure of the major tea catechins, gallates are found in a variety of plants and thus food components. We asked whether the structure of gallate might act as a pharmacophore in the enhancement of the effects of MNP-cell interactions. Uptake of dextran-coated MNPs by glioma cells and cell-associated MNPs (MNPcell) were respectively analyzed by confocal microscopy and a colorimetric iron assay. Co-incubation of MNPs and gallates, such as gallic acid and methyl gallate, induced a concentration-dependent increase in MNPcell, which was associated with co-localization of internalized MNPs and lysosomes. An analysis of the structure-activity relationship (SAR) revealed that the galloyl moiety exerted the most prominent enhancement effects on MNPcell which was further potentiated by the application of magnetic force; catechol coupled with a conjugated carboxylic acid side chain displayed comparable effects to gallate. Blockade or reduction in the number of hydroxyl groups rendered these compounds less effective, but without inducing cytotoxicity. The SAR results suggest that neighboring hydroxyl groups on the aromatic ring form an essential scaffold for the uptake effects; a similar SAR on antioxidant activities was also observed using a free radical-scavenging method. The results provide pivotal information for theranostic applications of gallates by facilitating nanoparticle-cell interactions and nanoparticle internalization by tumor cells.

Modeling of magnetoliposome uptake in human pancreatic tumor cells in vitro

The internalization kinetics resulting from magnetic nanoparticle interactions with tumor cells play an important role in nanoparticle-based cancer treatment efficiency. Here, the uptake kinetics of magnetoliposomes (ML) into human pancreatic tumor cells (MiaPaCa-2 and BxPC-3) are quantified using magnetic particle spectrometry. A comparison to the uptake kinetics for healthy L929 cells is given. The experimental results are used for the development of an uptake kinetics model describing the three relevant internalization processes: ML adsorption to the cell membrane, endo- and exocytosis. By fitting of experimental data, the rate constant of each internalization process is determined enabling the prediction of internalized ML at any incubation time. After seven hours incubation time, MiaPaCa-2 internalized three times more ML than BxPC-3 and L929 cells even though their ML adsorption rate constants were nearly the same. As the interaction of the ML with the cell membrane is non-specific, the uptake kinetics mirror the individual cell response to ML internalization. With a new mathematical term to cover the exocytosis contribution to the overall internalization process, the extended uptake kinetics model offers new possibilities to analyze the specific internalization mechanism for other nanoparticle and cell types.

Magneto-mechanical Stimulation of Bone Marrow Mesenchymal Stromal Cells for Chondrogenic Differentiation Studies

Mechanical interaction of cells and their surroundings are prominent in mechanically active tissues such as cartilage. Chondrocytes regulate their growth, matrix synthesis, metabolism, and differentiation in response to mechanical loadings. Cells sense and respond to applied physical forces through mechanosensors such as integrin receptors. Herein, we examine the role of mechanical stimulation of integrins in regards to their mechanotransduction ability to promote chondrogenesis. For this purpose, magnetic nanoparticles were chemically bonded to cell membrane mechanoreceptors and stimulated. Histological results showed the endocytosis of nanoparticles over the experimental period, pointing out the inefficient mechanical stimulation of the mechanoreceptors. Moreover, gene expression analysis only showed significant upregulation for SOX9, whereas type II collagen and aggrecan gene expression were not significantly different from the control group. Our results suggest that magneto-mechanical stimulation studies using magnetic nanoparticles should not only focus on the mechanical aspects, but also the interaction of magnetic nanoparticles with intracellular machinery should be investigated as well.

The use of pulsed magnetic fields to increase the uptake of iron oxide nanoparticles by living cells

Remote control of the interaction of magnetic nanoparticles with cells is fundamental to any potential downstream applications of magnetic nanoparticles such as gene and drug delivery vehicles and magnetic cell labeling. Thus, approaches based on the application of external magnetic fields to increase the efficiency of magnetic cell labeling are desirable. Here, we report a simple approach that enhances magnetic cell labeling using pulsed magnetic fields. The rate of uptake of superparamagnetic iron oxide nanoparticles (SPIONs) and transport across the cell membrane were enhanced upon application of a high intensity (7 T) short pulse width (∼15 μs) magnetic field. We present a quantitative analysis and mechanistic explanation of how a pulsed magnetic field influences the uptake of SPIONs by cells. Our findings offer insights into the mechanics of how pulsed magnetic fields can be effectively used to optimize magnetic cell labeling, which can provide a basis for better controlled biomedical applications of SPIONs.

Silicone Oil Swelling Slippery Surfaces Based on Mussel-Inspired Magnetic Nanoparticles with Multiple Self-Healing Mechanisms

In this work, a novel substrate building block, magnetic Fe3O4 nanoparticles armed with dopamine molecules were developed via mussel-inspired metal-coordination bonds. Combined with glycidyl methacrylate, polydimethylsiloxane propyl ether methacrylate, and diethylenetriamine, the original silicone oil swelling slippery liquid-infused porous surfaces (SLIPS) were first prepared by reversible coordinate bonds and strong covalent bonds cross-linking process. The matrix mechanical characteristics and surface physicochemical properties were systematically investigated. Results showed that the mechanical property of copolymer matrix and surface wettability of SLIPS can be remarkably recovered, which were due to the synergistic interactions of magnetic nanoparticles' intrinsic photothermal effect, reversible Fe-catechol coordination, and diffused lubricating liquid. After irradiating with sunlamp for 2 h and sequentially healing for 10 h under ambient conditions, the crack almost disappeared under optical microscopy with 78.25% healing efficiency (HEf) of toughness, and surface slippery was completely retrieved to water droplets. The efficient self-heal of copolymer matrix (66.5% HEf after eighth cutting-healing cycle) and recovering of slipperiness (SA < 5° and 5° < SA < 17° after fourth and eighth cutting-centrifuging-healing cycles, respectively) would extend longevity of SLIPS when subjected to multiple damages. Moreover, the prepared SLIPS displayed superb self-cleaning and liquid-repellent properties to a wide range of particulate contaminants and fluids.

Magnetic phase separation and unusual scenario of its temperature evolution in porous carbon-based nanomaterials doped with Au and Co

Two porous glassy carbon-based samples doped with Au and Co were investigated. The magnetization study as well as measurements of the nonlinear longitudinal response to a weak ac field (NLR) and electron magnetic resonance give evidences for a presence of magnetic nanoparticles (MNPs) embedded in paramagnetic/ferromagnetic matrix respectively, both samples being in magnetically phase-separated state at temperatures above 300K. Matrix, forming by paramagnetic centers located in matrix outside the MNPs, reveals exchange interactions providing its ferromagnetic (FM) ordering below TC≈ 210K in Au-doped sample and well above 350K in Co-doped one. For the former, NLR data suggest a percolation character of the matrix long-range FM order, which is mainly caused by a porous amorphous sample structure. Temperature dependence of the magnetization in the Au-doped sample evidences presence of antiferromagnetic (AF) interactions of MNPs with surrounding matrix centers. At magnetic ordering below TC these interactions promote origination of “domains” involving matrix fragment and surrounding MNPs with near opposite orientation of their moments that decreases the magnetostatic energy. On further cooling, the domains exhibit AF ordering below Tcr∼140K<TC, resulting in formation of a peculiar “ferrimagnet”. The porous amorphous structure leads to absence of translational and other symmetry features through the samples that allows canted ordering of magnetic moments in domains and in whole sample providing “canted ferrimagnetism”. At low temperatures Ttr∼3K, “order-oder” transition, evidencing the non-Heisenberg character of this magnetic material, occurs from ordering like “canted ferrimagnet” to FM alignment, which is stimulated by external magnetic field. The data for Co-doped sample imply the similar evolution of magnetic state but at higher temperatures above 350K. This state exhibits more homogeneous arrangement of the FM nanoparticles and the FM matrix. Order-order transition occurs in it at higher Ttr∼10–15K as well and followed by formation of long-range FM ordering found earlier by neutron diffraction. Doping of carbon-based nanomaterials by magnetic metals provides advantages for their possible practical applications as Co-doped sample with higher TC (>350K) and larger remanent magnetization evidences.

Interaction of Magnetic Nanoparticles with Lyotropic Liquid Crystal Studied by AFM

Interaction of Magnetic Nanoparticles with Lyotropic Liquid Crystal Studied by AFM

Role of inter-particle force between micro and nano magnetic particles on the stability of magnetorheological fluid

The concept of phase condensation of larger size particles in a poly-dispersed magnetic fluid (also known as ferrofluid) is employed as a tool to investigate the interaction of nanoparticles with micro particles in magnetorheological (MR) fluid. Two different shapes iron micron sized particles are used in MR fluid formulation: spherical and flake shaped. The magnetic fluid is used as a base carrier having three different magnetic nanoparticles volume fraction (0.2%, 0.6% and 0.8%). The study suggests that the interaction of magnetic nanoparticles with micron sized particle depends on the geometrical shape of the particle as well as surface roughness. The sedimentation ratio of flake shaped MR fluid increases with nanoparticles volume fractions while for spherical particles it remains virtually constant. The supernatant fluid analysis suggests that, larger sized particle fraction from magnetic fluid are attached to the surface of micron sized flake shape particles, which results in reduction of sliding friction between the particles and small sized fraction clouds around the flake. The atomic force microscopy results suggest that the surface roughness of flake shape particles are nearly 5 times higher than spherical shape particles. The role of these two different interactions is reflected in the sedimentation ratio of MR fluid.