Plasma-assisted synthesis of carbon encapsulated magnetic nanoparticles with controlled sizes correlated to smooth variation of magnetic properties

Implementation of magnetic nanoparticles in biomedicine requires their passivation, which often comes at a cost of diminished magnetic properties. For the design of nano-agents with targeted magnetic behaviour, it is...

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Wet-spinning of magneto-responsive helical chitosan microfibers

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.11.83 ◽

2020 ◽

Vol 11 ◽

pp. 991-999

Author(s):

Dorothea Brüggemann ◽

Johanna Michel ◽

Naiana Suter ◽

Matheus Grande de Aguiar ◽

Michael Maas

Keyword(s):

Tissue Engineering ◽

Magnetic Properties ◽

Magnetic Nanoparticles ◽

Mechanical Energy ◽

Accessible Surface Area ◽

Wet Spinning ◽

Helical Structures ◽

Structural Reinforcement ◽

Electron Microscopy Analysis ◽

Accessible Surface

Helical structures can be found in nature at various length scales ranging from the molecular level to the macroscale. Due to their ability to store mechanical energy and to optimize the accessible surface area, helical shapes contribute particularly to motion-driven processes and structural reinforcement. Due to these special features, helical fibers have become highly attractive for biotechnological and tissue engineering applications. However, there are only a few methods available for the production of biocompatible helical microfibers. Given that, we present here a simple technique for the fabrication of helical chitosan microfibers with embedded magnetic nanoparticles. Composite fibers were prepared by wet-spinning and coagulation in an ethanol bath. Thereby, no toxic components were introduced into the wet-spun chitosan fibers. After drying, the helical fibers had a diameter of approximately 130 µm. Scanning electron microscopy analysis of wet-spun helices revealed that the magnetic nanoparticles agglomerated into clusters inside the fiber matrix. The helical constructs exhibited a diameter of approximately 500 µm with one to two windings per millimeter. Due to their ferromagnetic properties they are easily attracted to a permanent magnet. The results from the tensile testing show that the helical chitosan microfibers exhibited an average Young’s modulus of 14 MPa. By taking advantage of the magnetic properties of the feedstock solution, the production of the helical fibers could be automated. The fabrication of the helical fibers was achieved by utilizing the magnetic properties of the feedstock solution and winding the emerging fiber around a rotating magnetic collector needle upon coagulation. In summary, our helical chitosan microfibers are very attractive for future use in magnetic tissue engineering or for the development of biocompatible actuator systems.

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Effect of aluminum doped iron oxide nanoparticles on magnetic properties of the polyacrylonitrile nanofibers

Journal of Polymer Engineering ◽

10.1515/polyeng-2015-0303 ◽

2017 ◽

Vol 37 (2) ◽

pp. 135-141

Author(s):

Armin Ourang ◽

Soheil Pilehvar ◽

Mehrzad Mortezaei ◽

Roya Damircheli

Keyword(s):

Magnetic Properties ◽

Iron Oxide ◽

Magnetic Nanoparticles ◽

Iron Oxide Nanoparticles ◽

Oxide Nanoparticles ◽

Negative Interaction ◽

Magnetic Nanofibers

Abstract In this work, polyacrylonitrile (PAN) was electrospun with and without magnetic nanoparticles (aluminum doped iron oxide) and was turned into magnetic nanofibers. The results showed that nanofibers diameter decreased from 700 nm to 300 nm by adding nanoparticles. Furthermore, pure PAN nanofibers were indicated to have low magnetic ability due to polar bonds that exist in their acrylonitrile groups. Obviously by adding only 4 wt% of the nanoparticles to PAN nanofibers, magnetic ability soared by more than 10 times, but at a higher percentage, it was shown to change just a little due to negative interaction among nanoparticles. This event relates to antiferromagnetically coupling of nanoparticles due to incomplete dispersion at higher percentage.

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Chemical synthesis of Nd2Fe14B hard phase magnetic nanoparticles with an enhanced coercivity value: effect of CaH2 amount on the magnetic properties

New Journal of Chemistry ◽

10.1039/c6nj02436j ◽

2016 ◽

Vol 40 (12) ◽

pp. 10181-10186 ◽

Cited By ~ 10

Author(s):

Ji Hun Jeong ◽

Hao Xuan Ma ◽

Doyun Kim ◽

Chang Woo Kim ◽

In Ho Kim ◽

...

Keyword(s):

Magnetic Properties ◽

Magnetic Nanoparticles ◽

Chemical Synthesis ◽

Diffusion Process ◽

Hard Phase ◽

Synthesis Route ◽

Value Effect ◽

Chemical Synthesis Route ◽

And Diffusion

Nd2Fe14B hard phase magnetic nanoparticles were successfully synthesized using a chemical synthesis route followed by a reduction and diffusion process without consuming a large amount of energy.

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Inductive Thermal Effect of Ferrite Magnetic Nanoparticles

Materials ◽

10.3390/ma12193208 ◽

2019 ◽

Vol 12 (19) ◽

pp. 3208 ◽

Cited By ~ 14

Author(s):

Jeotikanta Mohapatra ◽

Meiying Xing ◽

J. Ping Liu

Keyword(s):

Magnetic Properties ◽

Magnetic Nanoparticles ◽

Spinel Ferrite ◽

Particle Interactions ◽

Heat Induction ◽

Heating Efficiency ◽

Magnetic Parameters ◽

Thermally Activated ◽

Cell Functions ◽

Magnetic Heating

Localized heat induction using magnetic nanoparticles under an alternating magnetic field is an emerging technology applied in areas including, cancer treatment, thermally activated drug release and remote activation of cell functions. To enhance the induction heating efficiency of magnetic nanoparticles, the intrinsic and extrinsic magnetic parameters influencing the heating efficiency of magnetic nanoparticles should be effectively engineered. This review covers the recent progress in the optimization of magnetic properties of spinel ferrite nanoparticles for efficient heat induction. The key materials factors for efficient magnetic heating including size, shape, composition, inter/intra particle interactions are systematically discussed, from the growth mechanism, process control to chemical and magnetic properties manipulation.

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Functionalization of Magnetic Nanoparticles by Folate as Potential MRI Contrast Agent for Breast Cancer Diagnostics

Molecules ◽

10.3390/molecules25184053 ◽

2020 ◽

Vol 25 (18) ◽

pp. 4053

Author(s):

Hamid Heydari Sheikh Hossein ◽

Iraj Jabbari ◽

Atefeh Zarepour ◽

Ali Zarrabi ◽

Milad Ashrafizadeh ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Properties ◽

Magnetic Nanoparticles ◽

Magnetic Resonance ◽

Cancer Diagnostics ◽

Mri Contrast Agent ◽

Resonance Imaging ◽

Ir Transmission ◽

Average Size ◽

Coating Agents

In recent years, the intrinsic magnetic properties of magnetic nanoparticles (MNPs) have made them one of the most promising candidates for magnetic resonance imaging (MRI). This study aims to evaluate the effect of different coating agents (with and without targeting agents) on the magnetic property of MNPs. In detail, iron oxide nanoparticles (IONPs) were prepared by the polyol method. The nanoparticles were then divided into two groups, one of which was coated with silica (SiO2) and hyperbranched polyglycerol (HPG) (SPION@SiO2@HPG); the other was covered by HPG alone (SPION@HPG). In the following section, folic acid (FA), as a targeting agent, was attached on the surface of nanoparticles. Physicochemical properties of nanostructures were characterized using Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and a vibrating sample magnetometer (VSM). TEM results showed that SPION@HPG was monodispersed with the average size of about 20 nm, while SPION@SiO2@HPG had a size of about 25 nm. Moreover, HPG coated nanoparticles had much lower magnetic saturation than the silica coated ones. The MR signal intensity of the nanostructures showed a relation between increasing the nanoparticle concentrations inside the MCF-7 cells and decreasing the signal related to the T2 relaxation time. The comparison of coating showed that SPION@SiO2@HPG (with/without a targeting agent) had significantly higher r2 value in comparison to Fe3O4@HPG. Based on the results of this study, the Fe3O4@SiO2@HPG-FA nanoparticles have shown the best magnetic properties, and can be considered promising contrast agents for magnetic resonance imaging applications.

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Novel Benchtop Magnetic Particle Spectrometer for Process Monitoring of Magnetic Nanoparticle Synthesis

Nanomaterials ◽

10.3390/nano10112277 ◽

2020 ◽

Vol 10 (11) ◽

pp. 2277

Author(s):

Norbert Löwa ◽

Dirk Gutkelch ◽

Ernst-Albrecht Welge ◽

Roland Welz ◽

Florian Meier ◽

...

Keyword(s):

Magnetic Properties ◽

Magnetic Nanoparticles ◽

Process Monitoring ◽

Magnetic Nanoparticle ◽

Magnetic Particle ◽

Nanoparticle Synthesis ◽

Separation Processes ◽

Magnetic Detector ◽

Application Fields

Magnetic nanoparticles combine unique magnetic properties that can be used in a variety of biomedical applications for therapy and diagnostics. These applications place high demands on the magnetic properties of nanoparticles. Thus, research, development, and quality assurance of magnetic nanoparticles requires powerful analytical methods that are capable of detecting relevant structural and, above all, magnetic parameters. By directly coupling nanoparticle synthesis with magnetic detectors, relevant nanoparticle properties can be obtained and evaluated, and adjustments can be made to the manufacturing process in real time. This work presents a sensitive and fast magnetic detector for online characterization of magnetic nanoparticles during their continuous micromixer synthesis. The detector is based on the measurement of the nonlinear dynamic magnetic response of magnetic nanoparticles exposed to an oscillating excitation at a frequency of 25 kHz, a technique also known as magnetic particle spectroscopy. Our results underline the excellent suitability of the developed magnetic online detection for coupling with magnetic nanoparticle synthesis based on the micromixer approach. The proven practicability and reliability of the detector for process monitoring forms the basis for further application fields, e.g., as a monitoring tool for chromatographic separation processes.

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Impact of Gadolinium on the Structure and Magnetic Properties of Nanocrystalline Powders of Iron Oxides Produced by the Extraction-Pyrolytic Method

Materials ◽

10.3390/ma13184147 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4147

Author(s):

Vera Serga ◽

Regina Burve ◽

Mikhail Maiorov ◽

Aija Krumina ◽

Ramūnas Skaudžius ◽

...

Keyword(s):

Magnetic Properties ◽

Iron Oxide ◽

Magnetic Nanoparticles ◽

Thermal Treatment ◽

Iron Oxides ◽

Caproic Acid ◽

Transformation Process ◽

Nanocrystalline Powders ◽

Preparation Conditions ◽

Oxide Phases

Interest in magnetic nanoparticles is primarily due to their practical use. In this work, for the production of nanocrystalline powders of pure and gadolinium doped iron oxides, the extraction-pyrolytic method (EPM) was used. As a precursor, either iron-containing extract (iron (III) caproate in caproic acid) or its mixture with gadolinium-containing extract (gadolinium (III) valerate in valeric acid) was used. The mixed precursor contained 0.5 mol %, 2.5 mol %, 12.5 mol %, 50 mol %, and 75 mol % gadolinium in relation to the iron content. The formation of iron oxide phases, depending on the preparation conditions, was investigated. According to the results obtained, it was demonstrated that the presence of more than 2.5 mol % gadolinium additive in the mixed precursor inhibits the magnetite-to-hematite transformation process during thermal treatment. Produced samples were characterized by XRD and SEM methods, and the magnetic properties were studied.

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Bio-Catalysis and Biomedical Perspectives of Magnetic Nanoparticles as Versatile Carriers

Magnetochemistry ◽

10.3390/magnetochemistry5030042 ◽

2019 ◽

Vol 5 (3) ◽

pp. 42 ◽

Cited By ~ 9

Author(s):

Muhammad Bilal ◽

Shahid Mehmood ◽

Tahir Rasheed ◽

Hafiz M. N. Iqbal

Keyword(s):

Magnetic Field ◽

Magnetic Properties ◽

Magnetic Nanoparticles ◽

Molecular Level ◽

State Of The Art ◽

Volume Ratio ◽

Controlled Drug Delivery ◽

High Mass ◽

Biological Interactions ◽

Magnetic Carriers

In recent years, magnetic nanoparticles (MNPs) have gained increasing attention as versatile carriers because of their unique magnetic properties, biocatalytic functionalities, and capabilities to work at the cellular and molecular level of biological interactions. Moreover, owing to their exceptional functional properties, such as large surface area, large surface-to-volume ratio, and mobility and high mass transference, MNPs have been employed in several applications in different sectors such as supporting matrices for enzymes immobilization and controlled release of drugs in biomedicine. Unlike non-magnetic carriers, MNPs can be easily separated and recovered using an external magnetic field. In addition to their biocompatible microenvironment, the application of MNPs represents a remarkable green chemistry approach. Herein, we focused on state-of-the-art two majorly studied perspectives of MNPs as versatile carriers for (1) matrices for enzymes immobilization, and (2) matrices for controlled drug delivery. Specifically, from the applied perspectives of magnetic nanoparticles, a series of different applications with suitable examples are discussed in detail. The second half is focused on different metal-based magnetic nanoparticles and their exploitation for biomedical purposes.

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