Iron Oxide Fe3O4 Nanoparticles Research Articles

Effects of foliar iron oxide nanoparticles (Fe3O4) application on photosynthetic parameters, distribution of mineral elements, magnetic behaviour, and photosynthetic genes in tomato (Solanum lycopersicum var. cerasiforme) plants

This study aims to examine the effect of foliar magnetic iron oxide (Fe3O4) nanoparticles (IONP) application on the physiology, photosynthetic parameters, magnetic character, and mineral element distribution of cherry tomatoes (Solanum lycopersicum var. cerasiforme). The IONP suspension (500 mg L−1) was sprayed once (S1), twice (S2), thrice (S3), and four times (S4) a week on seedlings. Upon 21 days of the treatments, photosynthetic parameters (chlorophyll, carotenoids, photosynthetic yield, electron transport rate) were elucidated. Inductively-coupled plasma-optical emission spectrometer (ICP-OES) and vibrating sample magnetometer (VSM) were used to determine the mineral elements and abundance of magnetic power in the seedlings. In addition, the RT-qPCR method was performed to quantify the expressions of photosystem-related (PsaC, PsbP6, and PsbQ) and ferritin-coding (Fer-1 and Fer-2) genes. Results revealed that the physiological and photosynthetic indices were improved upon S1 treatment. The optimal dosage of IONP spraying enhances chlorophyll, carotenoid, electron transport rate (ETR), and effective photochemical quantum yield of photosystem II (Y(II)) but substantially diminishes non-photochemical quenching (NPQ). However, frequent IONP applications (S2, S3, and S4) caused growth retardation and suppressed the photosynthetic parameters, suggesting a toxic effect of IONP in recurrent treatments. Fer-1 and Fer-2 expressions were strikingly increased by IONP applications, suggesting an attempt to neutralize the excess amount of Fe ions by ferritin. Nevertheless, frequent IONP treatment fluctuated the mineral distribution and caused growth inhibition. Although low-repeat foliar applications of IONP (S1 in this study) may help improve plant growth, consecutive applications (S2, S3, and S4) should be avoided.

Impact of airborne iron oxide nanoparticles on Tillandsia usneoides as a model plant to assess pollution in heavy traffic areas

Due to the increasing evidence of widespread sub-micron pollutants in the atmosphere, the impact of airborne nanoparticles is a subject of great relevance. In particular, the smallest particles are considered the most active and dangerous, having a higher surface/volume ratio. Here we tested the effect of iron oxide (Fe3O4) nanoparticles (IONPs) with different mean diameter and size distribution on the model plant Tillandsia usneoides.Strands were placed in home-built closed boxes and exposed to levels of airborne IONPs reported for the roadside air, i.e. in the order of 107 - 108 items m−2. Plant growth and other morpho-physiological parameters were monitored for two weeks, showing that exposure to IONPs significantly reduced the length increment of the treated strands with respect to controls. A dose-dependence of this impairing effect was found only for particles with mean size of a few tens of nanometers. These were also proved to be the most toxic at the highest concentration tested. The IONP-induced hamper in growth was correlated with altered concentration of macro- and micronutrients in the plant, while no significant variation in photosynthetic activity was detected in treated samples. Microscopy investigation showed that IONPs could adhere to the plant surface and were preferentially located on the trichome wings.Our results report, for the first time, evidence of the negative effects of airborne IONP pollution on plant health, thus raising concerns about related environmental risks.Future research should be devoted to other plant species and pollutants to assess the impact of airborne pollution on plants and devise suitable attenuation practices.

Integrin-Targeted Theranostic Nanoparticles for Clinical MRI-Traceable Treatment of Liver Fibrosis.

Liver fibrosis is the critical stage in the development of chronic liver disease (CLD), from simple injury to irreversible cirrhosis. Timely detection and intervention of liver fibrosis are crucial for preventing CLD from progressing into a fatal condition. Herein, we developed iron oxide (Fe3O4) nanoparticles (IONPs) and ferulic acid (FA) coencapsulated poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs), followed by surface modification with cRGD peptides (cRGD-PLGA/IOFA) for integrin-targeted clinical magnetic resonance imaging (MRI)-traceable treatment of liver fibrosis. The cRGD peptide linked on the surface of the PLGA/IOFA NPs could specifically bind to the overexpressed integrin αvβ3 on activated hepatic stellate cells (HSCs) in the fibrotic liver, enabling the high-sensitive clinical MR imaging (3 T) and precise staging of liver fibrosis. The FA encapsulated in cRGD-PLGA/IOFA showed excellent efficacy in reducing oxidative stress and inhibiting the activation of HSCs through the transforming growth factor-β (TGF-β)/Smad pathway. Notably, the IONPs encapsulated in cRGD-PLGA/IOFA NPs could alleviate liver fibrosis by regulating hepatic macrophages through the NF-κB pathway, lowering the proportion of Ly6Chigh/CD86+, and degrading collagen fibers. The FA and IONPs in the cRGD-PLGA/IOFA produced a synergistic enhancement effect on collagen degradation, which was more effective than the IONPs treatment alone. This study demonstrates that cRGD-PLGA/IOFA NPs could effectively relieve liver fibrosis by acting on macrophages and HSCs and provide a new strategy for the clinical MRI-traceable treatment of liver fibrosis.

Comprehensive investigations of (Au-Ag/Blood and Cu-Fe3O4/Blood) hybrid nanofluid over two rotating disks: Numerical and computational approach

The purpose of this work is to investigate the Darcy-Forchheimer flow of a hybrid nanofluid within two parallel discs. We combine gold Au, silver Ag, copper Cu, and iron oxide Fe3O4 nanoparticles with base fluid blood in this framework. An appropriate similarity variables technique is implemented to transform partial differential systems into ordinary systems. In the results validation section, the numerical result is evaluated using a higher-order precise algorithm (bvp4c), and determined to the analytical result is by making use of the firing approach. Pictorial judgments revealed the estimates of several physical variables that arise over the momentum distribution and thermal distribution profiles. As compared to nanofluid, hybrid nanofluid significantly improves heat transfer rate. The thermal profile is improved when the Brinkman number increases in value. As the porosity parameter is increased, the velocity profile decreases. As the amplitude of the rotation parameter increases, so does the pressure profile. The Darcy-Forchheimer medium investigation of a hybrid nano-fluid streaming through the middle of two parallel disks is addressed, taking into account viscous dissipation and heat radiation for various nanoparticles. Additionally, enough agreement is observed when the numerical findings are compared to previously reported and analytical data. As compared to simple nanofluids, hybrid nanofluids have shown higher thermal properties and stability, making them attractive candidates for thermal applications such as solar thermal systems, automotive cooling systems, heat sinks, engineering, medical fields, or thermal energy storage.

Iron Oxide Fe3O4 Nanoparticles with Intrinsic Conducting Polymers and Biochar to Improve the Electromagnetic Shielding Performance of Light Weight Absorption-Type Materials

Iron Oxide Fe3O4 Nanoparticles with Intrinsic Conducting Polymers and Biochar to Improve the Electromagnetic Shielding Performance of Light Weight Absorption-Type Materials

Iron Oxide Fe3O4 Nanoparticles with ICPs and Biochar to Improve Electromagnetic Shielding Performance

Iron Oxide Fe3O4 Nanoparticles with ICPs and Biochar to Improve Electromagnetic Shielding Performance

Iron oxide nanoparticles with photothermal performance and enhanced nanozyme activity for bacteria-infected wound therapy.

Metal-based nanomaterials usually have broad-spectrum antibacterial properties, low biological toxicity and no drug resistance due to their intrinsic enzyme-like catalytic properties and external field (magnetic, thermal, acoustic, optical and electrical) responsiveness. Herein, iron oxide (Fe3O4) nanoparticles (IONPs) synthesized by us have good biosafety, excellent photothermal conversion ability and peroxidase-like catalytic activity, which can be used to construct a photothermal-enzymes combined antibacterial treatment platform. IONPs with peroxide-like catalytic activity can induce H2O2 to catalyze the production of •OH in a slightly acidic environment, thus achieving certain bactericidal effects and increasing the sensitivity of bacteria to heat. When stimulated by near-infrared light, the photothermal effect could destroy bacterial cell membranes, resulting in cleavage and inactivation of bacterial protein, DNA or RNA. Meanwhile, it can also improve the catalytic activity of peroxidase-like and promote IONPs to catalyze the production of more •OH for killing bacteria. After IONPs synergistic treatment, the antibacterial rate of Escherichia coli and Staphylococcus aureus reached nearly 100%. It also has an obvious killing effect on bacteria in infected wounds of mice and can effectively promote the healing of S. aureus-infected wounds, which has great application potential in clinical anti-infection treatment.

Effectiveness of temperature-dependent properties of Au, Ag, Fe3O4, Cu nanoparticles in peristalsis of nanofluids

It is well established that change in temperature perturbs fluid properties, therefore present study analyzes MHD peristalsis of nanofluids with temperature dependent viscosity and thermal conductivity. Four different nanoparticles i.e. Gold (Au), Silver (Ag), Iron oxide (Fe3O4) and Copper (Cu) are used in the analysis. Joule heating with mixed convection is also taken into consideration. Modifications to the famous Maxwell's and Hamilton-Crosser's thermal conductivity models are proposed by incorporating the effects of temperature. Arising nonlinear system is solved numerically using the built-in package NDSolve in Mathematica under the assumption of long wavelength and low Reynolds number. Results are displayed through graphs and tables to facilitate the physical analysis. It is noted that temperature dependence of viscosity and thermal conductivity alter the results. It is deduced that heat transfer rate can be improved by addition of iron oxide nanoparticles. Comparison for various nanoparticles and thermal conductivity models is also presented. It is noticed that the Maxwell's model shows enhancement in the results of velocity, temperature and heat transfer rate. Also, iron oxide Fe3O4 nanoparticles provide better rate of heat transport at boundary as compared to other nanoparticles.

Matrix-dependent size modifications of iron oxide nanoparticles (Ferumoxytol) spiked into rat blood cells and plasma: Characterisation with TEM, AF4-UV-MALS-ICP-MS/MS and spICP-MS

Engineered nanoparticles such as iron oxide (Fe3O4) nanoparticles (IONPs) offer several benefits in nanomedicine, notably as contrast agents in magnetic resonance imaging (MRI). Ferumoxytol, a suspension of IONPs (with a manufacturer's reported particle diameter of 27 nm–30 nm) was characterized as a standard by spiking into rat blood plasma and cell fractions. Nanoparticle separation, and characterisation was investigated with asymmetric flow field-flow fractionation (AF4) coupled online to ultraviolet-visible spectroscopy (UV-VIS), multi-angle light scattering (MALS) and inductively coupled plasma mass spectrometry (ICP-MS) detectors; also with single particle inductively coupled plasma mass spectrometry (spICP-MS) and transmission electron microscopy (TEM). MALS signal of pristine Ferumoxytol indicated radii of gyration (Rg) between 15 and 28 nm for the Fe-containing fraction and 30–75 nm for the non-Fe fraction. IONPs spiked into blood plasma indicated a polydisperse distribution between 40 nm - 120 nm suggesting matrix-induced size alterations. Spiking of the IONPs into cells showed a shift in ICP-MS Fe signal to 15 min, however the MALS signal was undetected within the Fe containing fraction of the IONPs suggesting NP loss due to membrane-particle attraction. spICP-MS analysis of IONPs spiked in rat plasma suggested the release of Fe-containing colloids into plasma causing an increase in diameter of IONPs to 52 ± 0.8 nm; whereas no major variation in particle size and distribution of the IONPs spiked in cell fractions was observed (33.2 ± 2.0 nm) suggesting non-alteration of the NP Fe core. A complementary application of microscopic, light scattering, and mass spectrometry techniques for the characterisation of NPs in challenging biological matrices like blood has been demonstrated.

Low Temperature Synthesis of Superparamagnetic Iron Oxide (Fe3O4) Nanoparticles and Their ROS Mediated Inhibition of Biofilm Formed by Food-Associated Bacteria.

In the present study, a facile environmentally friendly approach was described to prepare monodisperse iron oxide (Fe3O4) nanoparticles (IONPs) by low temperature solution route. The synthesized nanoparticles were characterized using x-ray diffraction spectroscopy (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM) measurements, Fourier-Transform Infrared Spectroscopy (FTIR), and Thermogravimetric analysis (TGA) analyses. XRD patterns revealed high crystalline quality of the nanoparticles. SEM micrographs showed the monodispersed IONPs with size ranging from 6 to 9 nm. Synthesized nanoparticles demonstrated MICs of 32, 64, and 128 μg/ml against Gram negative bacteria i.e., Serratia marcescens, Escherichia coli, and Pseudomonas aeruginosa, respectively, and 32 μg/ml against Gram positive bacteria Listeria monocytogenes. IOPNs at its respective sub-MICs demonstrated significant reduction of alginate and exopolysaccharide production and subsequently demonstrated broad-spectrum inhibition of biofilm ranging from 16 to 88% in the test bacteria. Biofilm reduction was also examined using SEM and Confocal Laser Scanning Microscopy (CLSM). Interaction of IONPs with bacterial cells generated ROS contributing to reduced biofilm formation. The present study for the first time report that these IONPs were effective in obliterating pre-formed biofilms. Thus, it is envisaged that these nanoparticles with broad-spectrum biofilm inhibitory property could be exploited in the food industry as well as in medical settings to curtail biofilm based infections and losses.

Application of Electromagnetic Induction Technique to Measure the Void Fraction in Oil/Gas Two Phase Flow

In this work, electromagnetic induction technique of measuring void fraction in liquid/gas fuel flow was utilized. In order to improve the electric properties of liquid fuel, an iron oxide Fe3O4 nanoparticles at 3% was blended to enhance the liquid fuel magnetization. Experiments have been conducted for a wide range of liquid and gas superficial velocities. From the experimental results, it was realized that there is an existing linear relationship between the void fraction and the measured electromotive force, when induction coils were connected in series for excitation coils, regardless of increase or decrease CNG bubbles distribution in liquid fuel flow. Therefore, it was revealed that the utilized method yielded quite reasonable account for measuring the void fraction, showing good agreement with the other available measurement techniques in the two-phase flow, and also with the published literature of the bubbly flow pattern. From the results of the present investigation, it has been proven that the electromagnetic induction is a feasible technique for the actual measurement of void fraction in a Diesel/CNG fuel flow.

Folic acid-functionalized polyethylenimine superparamagnetic iron oxide nanoparticles as theranostic agents for magnetic resonance imaging and PD-L1 siRNA delivery for gastric cancer

Programmed death ligand-1 (PD-L1), which is highly expressed in gastric cancers, interacts with programmed death-1 (PD-1) on T cells and is involved in T-cell immune resistance. To increase the therapeutic safety and accuracy of PD-1/PD-L1 blockade, RNA interference through targeted gene delivery was performed in our study. We developed folic acid (FA)- and disulfide (SS)–polyethylene glycol (PEG)-conjugated polyethylenimine (PEI) complexed with superparamagnetic iron oxide Fe3O4 nanoparticles (SPIONs) as a siRNA-delivery system for PD-L1 knockdown. The characterization, binding ability, cytotoxicity, transfection efficiency, and cellular internalization of the polyplex were determined. At nitrogen:phosphate (N:P) ratios of 10 or above, the FA-PEG-SS-PEI-SPIONs bound to PD-L1 siRNA to form a polyplex with a diameter of approximately 120 nm. Cell-viability assays showed that the polyplex had minimal cytotoxicity at low N:P ratios. The FA-conjugated polyplex showed higher transfection efficiency and cellular internalization in the folate receptor-overexpressing gastric cancer cell line SGC-7901 than a non-FA-conjugated polyplex. Subsequently, we adopted the targeted FA-PEG-SS-PEI-SPION/siRNA polyplexes at an N:P ratio of 10 for function studies. Cellular magnetic resonance imaging (MRI) showed that the polyplex could also act as a T2-weighted contrast agent for cancer MRI. Furthermore, one of four PD-L1 siRNAs exhibited effective PD-L1 knockdown in PD-L1-overexpressing SGC-7901. To determine the effects of the functionalized polyplex on T-cell function, we established a coculture model of activated T cells and SGC-7901 cells and demonstrated changes in secreted cytokines. Our findings highlight the potential of this class of multifunctional theranostic nanoparticles for effective targeted PD-L1-knockdown therapy and MRI diagnosis in gastric cancers.

Construction of a biointerface for glucose oxidase through diazonium chemistry and electrostatic self-assembly technique

In this study, a new procedure for the fabrication of biosensors was developed. The method is based on the covalent attachment of nitrophenyl groups to the electrode surface via diazonium salt reaction followed by their conversion to amine moieties through electrochemical reduction and electrostatic layer-by-layer (LbL) assembly technique. In this procedure, highly stable iron oxide (Fe3O4) nanoparticles (IONPs), chitosan (CHIt), GOx, and Nile blue (NB) were assembled on the surface of aminophenyl modified glassy carbon electrode (AP/GCE) by LbL assembly technique. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize the interfaces. The surface coverage of the active GOx and Michaelis–Menten constant (K M) of the immobilized GOx were Γ = 3.38 × 10−11 mol cm−2 and 2.54 mM, respectively. The developed biosensor displayed a well-defined amperometric response for glucose determination with high sensitivity (8.07 μA mM−1) and low limit of detection (LOD) of 19.0 μM. The proposed approach allows simple biointerface regeneration by increasing pH which causes disruption of the ionic interactions and release of the electrostatic attached layers. The biosensor can then be reconstructed again using fresh enzyme. Simple preparation, good chemical and mechanical stabilities, and easy surface renewal are remarkable advantages of the proposed biosensor fabrication procedure.

Tuning Fe3O4 nanoparticle dispersion through pH in PVA/guar gum/electrospun membranes

Polyvinyl Alcohol (PVA)/guar gum (GG) membranes with different loads of paramagnetic iron oxide Fe3O4 nanoparticles were successfully electrospun using both non-alkaline and alkaline stock solutions. The nanoparticle homogeneity distribution was clearly enhanced in fibers obtained from alkaline stock solutions. This is mainly due to the interaction between GG and the metallic ion, which also leads to further dispersion of remained uncoated nanoparticles in the mixture. It was also noticed that GG favors nanoparticle stability in the mixture and contributes to nanoparticle encapsulation. X-ray results showed that all membranes were semi-crystalline. FTIR-ATR spectra showed that FeO absorption band intensity improved with increasing nanoparticle load, reaching saturation at 3.5mg/ml Fe3O4 concentration under alkaline conditions. VSM analyses showed that the nanoparticles are paramagnetic and were successfully incorporated by the fibers. In vitro biocompatibility tests using L929 cells indicates adequate levels of cytotoxicity and cell adhesion/proliferation assays for both membranes obtained from non-alkaline and alkaline stock solutions. Therefore, they have potential for biomedical applications as biodegradable wound dressing.

Solution voltammetry of 4 nm magnetite iron oxide nanoparticles.

The voltammetry of solution-dispersed magnetite iron oxide Fe3O4 nanoparticles is described. Their currents are controlled by nanoparticle transport rates, as shown with potential step chronoamperometry and rotated disk voltammetry. In pH 2 citrate buffer with added NaClO4 electrolyte, solution cyclic voltammetry of these nanoparticles (average diameter 4.4 ± 0.9 nm, each containing ca. 30 Fe sites) displays an electrochemically irreversible oxidation with E(PEAK) at ca. +0.52 V and an irreversible reduction with E(PEAK) at ca. +0.2 V vs Ag/AgCl reference electrode. These processes are presumed to correspond to the formal potentials for one-electron oxidation of Fe(II) and reduction of Fe(III) at their different sites in the magnetite nanoparticle structure. The heterogeneous electrode reaction rates of the nanoparticles are very slow, in the 10(-5) cm/s range. The nanoparticles are additionally characterized by a variety of tools, e.g., TEM, UV/vis, and XPS spectroscopies.

Iron Oxide Nanoparticle-induced Oxidative Stress and Genotoxicity in Human Skin Epithelial and Lung Epithelial Cell Lines

Iron oxide (Fe₃O₄) nanoparticles (IONPs) have received much attention for their utility in biomedical applications such as magnetic resonance imaging, drug delivery and hyperthermia. Recent studies reported that IONPs induced cytotoxicity in mammalian cells. However, little is known about the genotoxicity of IONPs following exposure to human cells. In this study, we investigated the cytotoxicity, oxidative stress and genotoxicity of IONPs in two human cell lines; skin epithelial A431 and lung epithelial A549. Prepared IONPs were polygonal in shape with a smooth surface and had an average diameter of 25 nm. IONPs (25-100 μg/ml) induced dose-dependent cytotoxicity in both types of cells, which was demonstrated by cell viability (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide) and lactate dehydrogenase leakage assays. IONPs were also found to induce oxidative stress in a dose-dependent manner, evident by depletion of glutathione and induction of reactive oxygen species (ROS) and lipid peroxidation. Comet assay revealed that level of DNA damage was higher with concentration of IONPs in both types of cells. Quantitative real-time PCR analysis showed that following the exposure of cells to IONPs, the expression levels of mRNA of caspase-3 and caspase-9 genes were higher. We also observed the higher activity of caspase-3 and caspase-9 enzymes in IONPs treated cells. Moreover, western blot analysis showed that protein expression level of cleaved caspase-3 was up-regulated by IONPs in both types of cells. Taken together, our data demonstrates that IONPs have potential to induce genotoxicity in A431 and A549 cells, which is likely to be mediated through ROS generation and oxidative stress. This study suggests that genotoxic effects of IONPs should be further investigated at in vivo level.

Structural architecture and magnetism control of metal oxides using surface grafting techniques

Hydrophilic iron oxide Fe3O4 nanoparticles (NPs) were prepared by a reverse micro-emulsion method. Functionalization of Fe3O4 NPs was then carried out via surface graft polymerization to achieve outstanding magnetic property. Characterization results indicate that grafted core–shell Fe3O4 displayed inverse spinel crystalline structure, while particle size and it’s distribution were controlled accordingly. The ferromagnetic behavior (60 A m2 kg−1) of grafted Fe3O4 NPs was restored close to bulk value through enhancement of Fe–O ionic bond.

Interaction of Iron Oxide Fe3O4 Nanoparticles and Alveolar Macrophages in Vivo

Aqueous suspension of magnetite nanoparticles with primary diameter of 10 nm were intratracheally administered into rat lungs. In 24 h, cells were isolated from bronchoalveolar lavage and examined under a transmission electron microscope. Alveolar macrophages demonstrated ability to actively uptake single nanoparticles and small aggregates composed of such particles, which then formed larger conglomerates inside fused phagosomes. Some of these mature phagosomes shed the membrane and free nanoparticles closely interacted with nuclear membrane and with cristae and mitochondrial membranes thereby inflicting pronounced damage to these intracellular structures. The loss of primary lysosomes can be viewed as indirect evidence attesting to the role played by diffusion of lysosomal hydrolytic enzymes in the final destruction of the alveolar macrophages provoked by nanoparticles.

Superparamagnetic nanoparticle-inclusion microbubbles for ultrasound contrast agents

We have developed a new type of ultrasound (US) contrast agent, consisting of a gas core, a layer of superparamagnetic iron oxide Fe3O4 nanoparticles (SPIO) and an oil in water outermost layer. The newly developed US contrast agent microbubbles have a mean diameter of 760 nm with a polydisperity index (PI) of 0.699. Our in vitro and in vivo experiments have shown that they have the following advantages compared to gas-encapsulated microbbubbles without SPIO inclusion: (1) they provide better contrast for US images; (2) the SPIO-inclusion microbubbles generate a higher backscattering signal; the mean grey scale is 97.9, which is 38.6 higher than that of microbubbles without SPIO; and (3) since SPIO can also serve as a contrast agent of magnetic resonance images (MRI) in vitro, they can be potentially used as contrast agents for double-modality (MRI and US) clinical studies.