Magnetic Composite Nanoparticles Research Articles

Preparation of organic-modified magadiite–magnetic nanocomposite particles as an effective nanohybrid drug carrier material for cancer treatment and its properties of sustained release mechanism by Korsmeyer–Peppas kinetic model

Preparation of organic-modified magadiite–magnetic nanocomposite particles as an effective nanohybrid drug carrier material for cancer treatment and its properties of sustained release mechanism by Korsmeyer–Peppas kinetic model

Synthesis of Multifunctional Nanoparticles for the Combination of Photodynamic Therapy and Immunotherapy.

Programmed death-ligand 1 protein (PD-L1) has been posited to have a major role in suppressing the immune system during pregnancy, tissue allografts, autoimmune disease and other diseases, such as hepatitis. Photodynamic therapy uses light and a photosensitizer to generate singlet oxygen, which causes cell death (phototoxicity). In this work, photosensitizers (such as merocyanine) were immobilized on the surface of magnetic nanoparticles. One peptide sequence from PD-L1 was used as the template and imprinted onto poly(ethylene-co-vinyl alcohol) to generate magnetic composite nanoparticles for the targeting of PD-L1 on tumor cells. These nanoparticles were characterized using dynamic light scattering, high-performance liquid chromatography, Brunauer-Emmett-Teller analysis and superconducting quantum interference magnetometry. Natural killer-92 cells were added to these composite nanoparticles, which were then incubated with human hepatoma (HepG2) cells and illuminated with visible light for various periods. The viability and apoptosis pathway of HepG2 were examined using a cell counting kit-8 and quantitative real-time polymerase chain reaction. Finally, treatment with composite nanoparticles and irradiation of light was performed using an animal xenograft model.

Strong and Stable Magnetorheological Fluids Based on Flaky Sendust-Co0.4Fe0.4Ni0.2 Nanocomposite Particles.

The magnetorheological (MR) performance of suspensions based on magnetic (flaky Sendust (FS))-magnetic (Co0.4Fe0.4Ni0.2) nanocomposite particles was investigated by using a vibrating sample magnetometer and a rotational rheometer. Flaky Sendust@Co0.4Fe0.4Ni0.2 nanocomposite particles were fabricated through wet chemical synthesis of Co0.4Fe0.4Ni0.2 on the surface of FS. The density of the resultant FS@Co0.4Fe0.4Ni0.2 was less than that of FS due to the pore/void formation in the composite particles. Because of the high saturation magnetization of Co0.4Fe0.4Ni0.2 (165 emu/g), FS@Co0.4Fe0.4Ni0.2 (145 emu/g) exhibited greater magnetization than bare FS (130 emu/g), which resulted in the good performance of FS@Co0.4Fe0.4Ni0.2-based MR fluids: the suspension exhibited a remarkably high yield stress, almost one order greater than that of MR fluids based on hierarchically structured (HS) Fe3O4 particles. In addition, the high drag coefficient of FS@Co0.4Fe0.4Ni0.2 in the liquid medium, in conjunction with its lower density, resulted in a substantially improved long-term stability, better than that of Co0.4Fe0.4Ni0.2- or FS-based suspensions. Although the density of the FS@Co0.4Fe0.4Ni0.2 nanoparticles is higher than that of HS-Fe3O4 particles, their stability is much better than the stability of HS-Fe3O4 particle's suspension. Manufactured magnetic-magnetic nanocomposite particles provide a feasible MR suspension of high MR performance and long-term stability.

Magnetic Nanoparticle Composites: Synergistic Effects and Applications.

Composite materials are made from two or more constituent materials with distinct physical or chemical properties that, when combined, produce a material with characteristics which are at least to some degree different from its individual components. Nanocomposite materials are composed of different materials of which at least one has nanoscale dimensions. Common types of nanocomposites consist of a combination of two different elements, with a nanoparticle that is linked to, or surrounded by, another organic or inorganic material, for example in a core‐shell or heterostructure configuration. A general family of nanoparticle composites concerns the coating of a nanoscale material by a polymer, SiO2 or carbon. Other materials, such as graphene or graphene oxide (GO), are used as supports forming composites when nanoscale materials are deposited onto them. In this Review we focus on magnetic nanocomposites, describing their synthetic methods, physical properties and applications. Several types of nanocomposites are presented, according to their composition, morphology or surface functionalization. Their applications are largely due to the synergistic effects that appear thanks to the co‐existence of two different materials and to their interface, resulting in properties often better than those of their single‐phase components. Applications discussed concern magnetically separable catalysts, water treatment, diagnostics‐sensing and biomedicine.

Mild Magnetic Hyperthermia-Activated Innate Immunity for Liver Cancer Therapy.

Magnetic hyperthermia therapy (MHT) is noninvasive and features excellent tissue penetration for deep-seated tumors, but unfortunately, it suffers the low therapeutic efficacy due to the limited magneto-thermal efficiency and insufficient intratumor accumulation of conventional intravenous-injected magnetic nanoparticles, which are actually mostly sequestered by the mononuclear phagocyte system, especially the liver. Such a disadvantageous characteristic of preferential liver uptake is here exploited, for the first time as far as we know, to treat orthotopic liver cancer by mild MHT using specially designed composite magnetic nanoparticles. A kind of core-shell-structured and Zn2+-doped Zn-CoFe2O4@Zn-MnFe2O4 superparamagnetic nanoparticles (ZCMF) has been synthesized which exhibits excellent and highly controllable magnetic hyperthermia performance owing to an exchange-coupled magnetism between the core and shell, and Zn2+ doping. The controllable mild MHT at 43-44 °C based on ZCMF demonstrates almost complete inhibition of liver cancer cell proliferation and tumor growth, which is associated with the suppression of heat shock protein 70 (HSP70) expression. More importantly, the mild MHT-treated liver cancer cells are capable of activating natural killer (NK) cells by dramatically upregulating the expression of UL16-binding proteins (ULBPs), ligands of natural killer group 2 member D (NKG2D). As a result, the growth of both xenograft tumors and orthotopic liver tumors were almost completely suppressed under mild MHT via induced NK-cell-related antitumor immunity in vivo. This work not only evidences the great potential of mild MHT but also reveals the underlying immunity activation mechanism in liver cancer treatment by mild MHT.

Synthesis of magnetic nanoparticles-containing nanocomposite hydrogel and its potential application for simulated radioactive wastewater treatment

Nanocomposite hydrogels, bearing different functional groups, are potential materials for removing contaminants from water with high capacity and selectivity. A novel polyfunctional nanocomposite hydrogel (NCHG) was developed for the treatment of radioactive waste. It is based on magnetic composite nanoparticles (MCNPs) formed by encapsulating magnetite in polystyrene-co-polymethacrylic acid (PS-co-PMAA) miniemulsion. The MCNPs were then used as a physical crosslinker for the graft polymerization of sodium styrene sulfonate SSS and acrylic acid AA in the presence of polyacrylamide PAM to form an interconnected NCHG bearing different functional groups. The NCHG was characterized by FTIR, DLS, and TEM. The results indicated that a successful encapsulation of magnetite NPs took place and the MCNPs were ~100 nm in size. The presence of the MCNPs in the graft polymerization system greatly enhanced the conversion %. The optimum ultrasound homogenization of the polymerization reaction was found to be 11 min and the optimum gamma radiation dose for the initiation of polymerization reaction was 25 kGy. The NCHG was used for the removal of Cs+, Co2+, and Sr2+ ions from simulated radioactive waste. The initial concentration was studied from 50 to 600 mg/L, and the equilibrium adsorption capacities of Cs+, Co2+, and Sr2+ were found to increase from 8.49 to 53.37, 11.17–80.69, and 10.75–65.35 mg/g, respectively. The calculated thermodynamic parameters namely, Gibbs free energy (ΔG°), Enthalpy (ΔH°) and entropy (ΔS°) indicated an endothermic chemisorption process.

Multifunctional metal-chelated phosphonate/Fe3O4 magnetic nanocomposite particles for defeating antibiotic-resistant bacteria

The expression and dissemination of β-lactamase enzymes is the most frequently used antibiotic resistance mechanism in bacteria. The synthesis and characterization of a new nanocomposite particle was performed to inhibit serine β-lactamase activities. The nanostructure based on an ultra-small iron oxide (Fe3O4) nanocore, is in-situ coated with a hydrophilic and biodegradable compound of N-phosphonomethyl iminodiacetic acid (PMIDA). Through amidation reaction, a tetra-dentate molecule such as (S)-N-(5-Amino-1-carboxypentyl) iminodiacetic acid (NTA) was covalently conjugated to the acid-terminated Fe-PMIDA nanoparticles. The resulted Fe-PMIDA-NTA nanostructure was further coordinated with Co2+ ions. Once the nanoparticles loaded with the cobalt ions, the positively charged nanocomposite particles were found effective toward class C β-lactamase having 66% inhibition of enzyme activity with an IC50 of 45.68 μg/mL. A significant level of synergism was also observed by co-administration of Fe-PMIDA-NTA-Co2+ NPs and cephalexin as our model of β-lactam antibiotic against Escherichia coli bacteria.

Epitope recognition of magnetic peptide-imprinted chitosan composite nanoparticles for the extraction of CRISPR/dCas9a proteins from transfected cells

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas9) technology is a powerful method for genetic modification (and regulation) that is of great current interest. The development of new, economical methods of detecting and extracting Cas9 (and/or dCas9) from transfected cells is thus an important advance. In this work, we employed molecular imprinting, using two peptides from the Cas9 protein, to make magnetic peptide-imprinted chitosan nanoparticles. dCas9 was encoded in a plasmid which was then transfected into human embryonic kidney (HEK293T) cells. The expression of dCas9 protein was measured by using total protein kits. Finally, the imprinted nanoparticles were used to extract dCas9 from transfected cell homogenates.

Study on Multifunctional Composite Nanomaterials for Controlled Drug Release in Biomedicine.

Nanoscience is a highly comprehensive, interdisciplinary discipline based on many advanced science and technology, and has developed very rapidly in the past few decades. Nanoscience and technology has been widely used in many fields such as biomedicine, materials science, chemistry, physics, and electronic information engineering. Nanomaterials are widely used due to their many excellent properties such as quantum size effects, small size effects, surface effects, and tunneling effects, and have become hot research areas. It is very suitable as a carrier for antitumor drug molecules, which is conducive to improving drug efficacy and reducing drugs side effects. After selective functionalization, it is highly possible to achieve the loading and release of multiple drug molecules. Based on the magnetic mesoporous Fe₃O₄-MSNs composite nanoparticles, we have modified a series of organosilane coupling agents on its surface. The most commonly used antitumor drug (adriamycin) in clinical was selected as a model to evaluate the loading and release behavior of modified composite nanoparticles Fe₃O₄-MSNs on this drug. The results indicate that Fe₃O₄ is selectively modified after appropriate modification of the silane coupling agent. MSNs carrier can effectively regulate the adsorption and release rate of hydrophilic DOX and hydrophobic PTX, and shows a good drug control ability.

Chemical synthesis and characterization of SmCo5/Co magnetic nanocomposite particles

Chemical synthesis and characterization of SmCo5/Co magnetic nanocomposite particles

An electroporation strategy to synthesize the membrane-coated nanoparticles for enhanced anti-inflammation therapy in bone infection.

The cell membrane-coated nanoparticles (MNPs) showed great potential in treating infectious disease due to their superior biofunctions in improving biocompatibility of nanoparticles and neutralization of pathogen or toxins. However, bone infection is accompanied with severe inflammation and bone loss, which also requires anti-inflammatory and osteoconductive treatment. The conventional membrane coating method has to undergo ultrasonication and extrusion procedures, which reduces the functionality of cell membrane and limits the choice of nanoparticles. In this study, we proposed an electroporation-based membrane coating strategy to facilitate the synthesis of MNPs to tackle those problems.Methods: Magnetic composite nanoparticles with osteoconductive Ca3(PO4)2 and bactericidal TiO2 were assembled into macrophages through phagocytosis and then collected to expose in electric field for obtaining macrophage membrane-coating nanoparticles. By using molecular dynamics simulation and materials characterizations, the cell membrane coating efficiency was confirmed. The in vitro anti-bacterial and anti-inflammatory abilities were tested by bacteria culturing and immune cells activation. Then drug-resistant bacteria induced bone infection model was established to verify its in vivo therapeutic effects.Results: The coated membrane prepared through electroporation reserved the integrality of membrane structure and right-sidedness, with more functional proteins. Those led to the superior properties of recognition and adsorption with bacteria, toxins and inflammatory cytokines. Owing to the benefits of electroporation, the MNPs exhibited significant better antibacterial and anti-inflammatory abilities for enhancing the tissue repair process.Conclusion: This study provides a novel self-assembly cell membrane coating strategy by electroporation to construct multifunctional membrane-coating nanoparticles for bone infection treatment. This strategy not only improves the functions of coated membrane, but is also proved to be universal for varies nanoparticles or cells, indicating a great potential for future applications in the bioengineering field.

Robust magnetic and electromagnetic wave absorption performance of reduced graphene oxide loaded magnetic metal nanoparticle composites

With the increasing demand for microwave absorbing materials, to develop a microwave absorber with a simple synthesis process is of great significance to the field of protection. Herein we have successfully loaded iron-cobalt-nickel oxide (FeCoNiOx) onto the as-prepared polydopamine-reduced graphene oxide (PDA-rGO) through a two-step process. The preparation method has mild reaction conditions without high temperature and pressure compared with the traditional method, which is conducive to large-scale production. Based on effectively combining dielectric loss and magnetic loss mechanism, the obtained material possesses excellent electromagnetic waves absorbing performance with the minimum RL value of −36.28 dB. The results proved that the composites can be endowed with various microwave absorption effects by the adjustion of different component ratios. In addition, the microwave absorption mechanism was dicussed in detail, and we believe that the results of our research have certain guiding significance for preparation of efficient microwave absorbers.

Multifunctional Fe3O4@SiO2-CDs magnetic fluorescent nanoparticles as effective carrier of gambogic acid for inhibiting VX2 tumor cells

This paper reports a dual-functional platform that can be used for synergistic therapy, including drug release and magnetic targeting. The platform is realized through an amide reaction between high-fluorescence carbon quantum dots (CD) prepared by microwave method and amino-functional Fe3O4@SiO2 with high saturation magnetic strength and a core-shell structure to obtain multifunctional magnetic fluorescent nanocomposite particles Fe3O4@SiO2-CDs. The structure, drug release behavior, cytotoxicity, fluorescence and distribution in vivo of Fe3O4@SiO2-CDs nanoparticles were studied. The results show that the Fe3O4@SiO2-CDs with a dynamic diameter of about 155.0 nm and a magnetic saturation intensity of 31.2 emu/g has a higher loading of gambogic acid (GA), and is more conducive to drug release in an environment of pH = 5.7. In addition, Fe3O4@SiO2-CDs has low cytotoxicity and can enter VX2 cells. However, GA-loaded Fe3O4@SiO2-CDs has an inhibitory effect on VX2 cells, and the cell survival rate is less than 20% at a concentration of 100 μg/mL. Magnetic targeting experiments show that bifunctional magnetic nanoparticles have an outstanding magnetic targeting effect on tumors.

Enhanced hyperthermia performance in hard-soft magnetic mixed Zn0.5CoxFe2.5 – x O4/SiO2 composite magnetic nanoparticles* *Project supported by the National Natural Science Foundation of China (Grant Nos. 51771124, 51571146, and 51701130).

High quality Zn0.5Co x Fe2.5 – x O4 (x = 0, 0.05, 0.1, 0.15) serial magnetic nanoparticles with single cubic structures were prepared by the modified thermal decomposition method, and Zn0.5Co x Fe2.5 – x O4/SiO2 composite magnetic nanoparticles were prepared by surface modification of SiO2. The magnetic anisotropy of the sample increases with the increase of the doping amount of Co2+. When the doping amount is 0.1, the sample shows the transition from superparamagnetism to ferrimagnetism at room temperature. In the Zn0.5Co x Fe2.5 – x O4/SiO2 serial samples, the maximum value of specific loss power (SLP) with 1974 W/gmetal can also be found at doping amount of x = 0.1. The composite nanoparticles are expected to be an excellent candidate for clinical magnetic hyperthermia.

Shirasu porous glass membrane processed uniform-sized Fe3O4-embedded polymethylmethacrylate nanoparticles and their tunable rheological response under magnetic field

We fabricated Fe3O4-polymethylmethacrylate (PMMA) magnetic composite nanoparticles using the Shirasu porous glass membrane process and investigated the magneto-responsive magnetorheological (MR) response of them under various applied magnetic fields when dispersed in silicone oil. The morphology and structure of the particles were observed through transmission electron microscopy, Fourier Transform-infrared spectroscopy, and X-ray diffraction. In addition, a typical MR behavior was confirmed when the MR fluid of the Fe3O4-PMMA nanoparticles was evaluated by a rotation rheometer under applied magnetic fields. The synthesized Fe3O4-PMMA magnetic composite nanoparticles exhibited a promising potential for application in a wide range of MR application prospects owing to its appropriate size, lower density, and better sedimentation stability.

Tailoring the Design of a Lanthanide Complex/Magnetic Ferrite Nanocomposite for Efficient Photoluminescence and Magnetic Hyperthermia Performance.

In this work, we have designed a magnetoluminescent nanocomposite as a single platform for optical imaging and safe magnetic hyperthermia therapy by optimizing the composition of magnetic nanoparticles and controlling the conjugation strategy of the luminescent lanthanide complex. We have synthesized CoxMn1-xFe2O4 nanoferrites, with x = 0 to 1 in 0.25 steps, from soft (MnFe2O4) to hard (CoFe2O4) ferrites of size (∼20 nm) following a one-pot oxidative hydrolysis method. We have performed the induction heating study with an aqueous dispersion of nanoferrites using an alternating magnetic field (AMF) of 12 kAm-1, 335 kHz. This shows an enhancement of heating efficiency with the increment of manganese content and attains the highest intrinsic loss power (ILP) of 6.47 nHm2 kg-1 for MnFe2O4 nanoparticles. We have then fabricated a magnetoluminescent nanocomposite employing MnFe2O4 nanoparticles as it shows outstanding heating performance within the threshold limit of AMF (≤5 × 109 Am-1 s-1). A layer-by-layer coating strategy is followed, where a pure silica coating of thickness ∼10 nm on MnFe2O4 nanoparticles is achieved before encapsulation of the luminescent complex of europium(III), 2-thenoyltrifluoroacetone, and 1,10-phenanthroline in the second layer of silica. This is to ensure the optimal distance between the magnetic core and Eu(III)-complex to pertain significant luminescence in the composite (Eu-MnFe2O4). The photoluminescence spectra of an aqueous dispersion of Eu-MnFe2O4 by excitation in the UV region show a narrow and strong emission at 612 nm, which is stable even after 72 h. The induction heating study of an aqueous dispersion of Eu-MnFe2O4 in 12 kAm-1, 335 kHz AMF shows an ILP as 4.02 nHm2 kg-1, which is remarkably higher than the hyperthermia efficiency of reported magnetoluminescent nanoparticles.

Non-toxic nano approach for wastewater treatment using Chlorella vulgaris exopolysaccharides immobilized in iron-magnetic nanoparticles

The current study, novel magnetic nano-composite particles (Fe3O4@EPS) were successfully synthesized via the co-precipitation of iron (III) chloride and iron (II) sulfate (Fe3O4 nanoparticles) with exopolysaccharides (EPS) derived from the microalga Chlorella vulgaris. The physico-chemical nature of the Fe3O4@EPS was investigated in depth. Transmission electron microscopy (TEM) results estimated the core-shell nature of Fe3O4@EPS aggregated inside the indistinctly layered EPS matrix to be 10–20 nm in size. Scanning electron microscopy-based energy dispersive spectral analysis indicated that elemental Fe was successfully loaded on to the EPS polymeric ion-exchanger at a rate of 63.3% by weight. FT-IR results demonstrated that Fe3O4 nanoparticles were successfully modified by the functional groups present in EPS. Fe3O4@EPS showed a highly magnetic nature at 5.0 emu/g. The XPS survey spectrum, which showed two major peaks at 724.1 and 710.2 eV revealed the elemental composition and electronic structure of Fe3O4 nanoparticles and Fe3O4@EPS. Furthermore, nutrient removal from wastewater was studied. Under optimum conditions (3.5 g/L of Fe3O4@EPS, pH 7.0 and 13 h of incubation) 91% of PO43− and 85% of NH4+were effectively eliminated. These findings demonstrate the potential of Fe3O4@EPS for removing PO43− and NH4+ in wastewater treatment plants.

Separating and Characterizing Functional Nitrogen Degraders via Magnetic Nanoparticle-Mediated Isolation

Magnetic nanoparticle-mediated isolation (MMI) is a new method for isolating active functional microbes from complex microorganisms without substrate labeling. In this study, the composition and properties of magnetic nanoparticles (MNPs) were characterized by a number of techniques, indicating that MNPs have characteristics such as microinterfaces and can be efficiently fixed on the surface of microbial cells. It also introduced the MMI technology in activated sludge after stable long-term treatment. With further addition of promotor carbon sources, the enrichment of the functional nitrogen degraders in MMI was significantly higher than in samples without MNPs, showing the advantages of MMI in identifying the active degraders. Redundancy analysis (RDA) also showed that the functional nitrogen degraders such as Comamonadaceae_unclassified and Thiobacillus absolutely dominated in situ ammonia degradation, and the change in dominant genera had the same trend as the degradation rate of ammonia nitrogen. In the magnetically functionalized system, the separated functional nitrogen degraders significantly improved ammonia nitrogen degradation efficiency, making it basically stable at more than 80%, up to 91.6%. These results prove that the complex flora created after the addition of MNPs is more adaptable to newly introduced pollutants, and MMI is a powerful tool for studying pollutant-degrading microorganisms under in situ conditions.

Synthesis and characterization of polymeric nanocomposites based on poly-melamine-paraformaldehyde and superparamagnetic silicon dioxide loaded Iron(III) oxidecore-shell composite magnetic nanoparticles

In this study, a novel magnetic nanomaterial was synthesized based on Schiff base condensation of low-cost materials under special conditions. A novel Fe3O4@SiO2 @PMF polymeric nanocomposites were prepared from a mixture containing poly-melamine-paraformaldehyde and silicon dioxide loaded Iron (III) oxide core-shell composite magnetic nanoparticles. The silicon dioxide (SiO2) was coated on iron (III) oxide )Fe3O4( magnetic nanoparticles (MNPs) by tetraethyl orthosilicate (TEOS) added via Stӧber method to prevent the core from oxidation or dissolving by acid solution and poly-melamine-paraformaldehyde (PMF) nanoparticles were modified the SiO2 loaded Fe3O4 in biocompatible solvents. Evaluation and characterization of synthesized product using Fourier-transform infrared spectroscopy (FTIR) analysis, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), vibrating sample magnetometry (VSM) and thermogravimetry analysis (TGA). According to the results, Fe3O4@SiO2@PMF MNPs have high thermal stability up to 450 oC with a %8 weight loss and furthermore VSM measurements indicated that the Fe3O4 and Fe3O4@SiO2 @PMF nanoparticles were superparamagnetic and the magnetization were 55.05emug-1 and 20.1emug-1 at room temparature, respectively.

Green Fabrication of Tannic Acid-Inspired Magnetic Composite Nanoparticles toward Cationic Dye Capture and Selective Degradation.

An environmental strategy for developing sustainable materials presents an attractive prospect for wastewater remediation. Herein, a facile, green, and economical strategy is proposed to fabricate magnetic composite nanoparticles (NPs) toward cationic dye adsorption and selective degradation. To prepare the composite TiO2-PEI-TA@Fe3O4 NPs, tannic acid (TA) and polyethyleneimine (PEI) were first used to decorate Fe3O4 NPs at aqueous solution, and then TiO2 NPs were anchored onto the surfaces of Fe3O4 NPs based on the catecholamine chemistry. The chemical composition and microstructure of the obtained NPs were systematically characterized. The NPs not only exhibited adsorption ability for the cationic dye of methylene blue (MB) but also responded to ultraviolet light to selectively degrade the adsorbed MB, and the removal (adsorption and/or degradation) ratio for MB could reach 95%. In addition, cyclic experiments showed that the removal ratio of the composite NPs for MB could still be maintained more than 85% even after five cycles. Given by the above-mentioned advantages, such a green and facile strategy for combining the adsorption and degradation methods to construct magnetic nanocomposites exhibits potential applications in cationic dye selective removal and sustainable wastewater remediation.