Size Of Iron Oxide Nanoparticles Research Articles

Impact of bacterial synthesized nanoparticles on quality attributes and postharvest disease control efficacy of apricot and loquat.

Postharvest fungal attacks on fruits such as apricots and loquats are common. Diseased fruit samples were collected from Murree's local fruit markets. The disease-causing pathogens were identified utilizing molecular, microscopic, and morphological characteristics. Alternaria alternata and Aspergillus niger were identified as the pathogens responsible for brown rot in loquat and black rot in apricot. To combat these fruit diseases, iron oxide (Fe2 O3 ) nanoparticles were synthesized using Bacillus subtilis and were characterized using various techniques. X-ray diffraction examination validated the size of iron oxide nanoparticles. The presence of several capping agents in the synthesized nanoparticles was confirmed by Fourier transform infrared analysis. Scanning electron microscopy revealed the spherical morphology of nanoparticles, whereas energy-dispersive X-ray proved the presence of different elemental compositions. After completing antifungal activities in vitro and in vivo, it was discovered that a nanoparticle concentration of 1.0mg/mL efficiently suppressed the growth of fungal mycelia. Fungi growth was effectively inhibited in fruit samples treated with 1.0mg/mL nanoparticles. The results of successful in vitro and in vivo antifungal activities imply that iron oxide (Fe2 O3 ) nanoparticles play an important role in ensuring fruit quality against pathogenic attacks. Bacterial-mediated iron oxide can be widely used because it is less expensive and less harmful to the environment than chemically manufactured fertilizers.

Impact of atomization and spray flow conditions on droplet [formula omitted]-explosions and temporal self-similarity in the FSP process

Flame spray pyrolysis (FSP) is a technique for the synthesis of metal oxide nanoparticles by combusting precursor solutions in a spray flame. The combustion of certain precursor solutions is known to lead to severe droplet disruptions (μ-explosions) in the spray flame that are linked to the synthesis of homogeneous and phase-pure nanoparticles. In this work, a broad spectrum of suitable subsonic operating conditions for the synthesis of iron oxide nanoparticles by FSP is investigated to understand the influence of the jet Reynolds number and turbulence on the onset of μ-explosions and droplet dynamics in spray flames. In order to enable a coherent comparison between differently operated spray flames using an iron(III) nitrate nonahydrate solution, the gas-to-liquid mass ratio and, hence, the oxygen/fuel ratio have been kept constant in order to identify the influence of flow conditions on the droplet dynamics. From the analysis of the droplet sizes in the spray and in the spray flame, it is found that in all combusting sprays, the droplet sizes convert from unimodal (after atomization) to bimodal droplet size distribution (DSD) due to the presence of μ-explosions. The occurrence and evolution of the bimodal DSD reveal that high jet Reynolds numbers result in narrower DSD and in a sharper separation of both DSD probability peaks (modal values). A straightforward 1-step kinematic model is presented to describe the conversion of unimodal to bimodal DSD considering the evaporation of droplets as well as the disruption of droplets to mimic the effect of μ-explosions. The temporal evolution of droplets in FSP is investigated by spatially resolved velocity data that reveal the formation of a temporal self-similarity. The resulting iron oxide nanoparticle size decreases with increasing jet Reynolds number. The turbulent mixing and residence times in the flame, primarily set by the jet Reynolds number, are identified as key design parameters for FSP.

High temperature flow synthesis of iron oxide nanoparticles: Size tuning via reactor engineering

Batch thermal decomposition syntheses of iron oxide nanoparticles (IONPs) provide precise control of particle properties, but their scalability and reproducibility is challenging. This is addressed in this work via a versatile high temperature flow reactor with adjustable temperature profiles through three individual stages operated between 180 °C and 280 °C. The tuneable temperature profiles in combination with self-seeded growth methods made it possible to synthesise IONPs between 2 and 17 nm (a size increase that corresponds to a >600 fold particle volume increase) at production rates of several gIONP per day. The precursor solutions contained only iron(III) acetylacetonate in a polyol solvent and no nucleation or growth inhibitors, oxidation or reducing agents, ligands or any other additives . This broad size range covers most biomedical applications and is of special interest for T1 MRI contrast agents (2–5 nm), as well as for magnetic hyperthermia cancer therapy (>10 nm). The potential of the IONPs produced was demonstrated by their high longitudinal relaxivity >16 mM−1s−1 at a transversal/longitudinal relaxivity ratio <2.5 (small IONPs) and specific absorption rates increasing with the IONP size up to180 W/gFe. In addition, the polyol method employed allowed for simple ligand exchange with biocompatible sodium tripolyphosphate to make the IONPs stable in water, thus rendering them suitable for biomedical applications. The continuous high temperature process presented shows how to control the particle size not via the chemistry (e.g., chemical additives affecting the particle size through the surface chemistry), but engineering parameters, i.e., reactor temperature profiles, reagent addition sequences and seeded growth strategies.

Exploring the impact of pH on the properties of citric acid-coated iron oxide nanoparticles as high-performance T2 contrast agent for MRI applications

Iron oxide nanoparticles (IONPs) were synthesized using an aqueous co-precipitation method at various pH levels ranging from 8 to 12. The impact of solution pH on IONPs' properties was analyzed by studying their size, shape, and surface charge. Both the crystalline structure and size of IONPs were significantly affected by pH levels, as revealed by X-ray diffraction analysis. Across all pH values, magnetite was found to be the predominant phase. Interestingly, the smallest nanoparticle size was observed at pH 10. The IONPs synthesized at the optimal pH were then coated with citric acid to be used as contrast agents in Magnetic Resonance Imaging (MRI). The citric acid coating was applied to the IONPs to increase their biocompatibility and optimize their dispersity. The coated samples were further characterized using Zetasizer, Fourier-Transform Infrared Spectroscopy (FTIR), and Vibrating Sample Magnetometry (VSM). The results indicated high stability and appropriate magnetization, with a relaxivity ratio (r2/r1) of 73.75, making citric acid-coated IONPs a promising candidate for use as T2 MRI contrast agents. FTIR, Zetasizer, and VSM measurements indicated that the citric acid coating had a positive effect on the biocompatibility, stability, and magnetization of the IONPs. IONPs are excellent T2 MRI contrast agents because of their enhanced physiochemical properties, and their high relaxivity ratio confirms their effectiveness. The findings of this study emphasize the crucial role that pH plays in determining the properties of IONPs and highlight the potential use of citric acid-coated IONPs in medical imaging applications such as MRI.

Fe3O4@SiO2 Core–Shell Nanoparticles: Synthesis, Characterization Prepared by Green Method for Iraqi Aloe Vera Extract

In this work, a green approach was used to create Fe3O4 nanoparticles. After that, ferrous chloride tetrahydrate and ferric chloride hexahydrate solutions were mixed with various quantities of Iraqi Aloe Vera gel and sodium hydroxide solution to achieve pH(8). Then, in the scale synthesis of silica-coated iron oxide NPs utilizing nontoxic and low-cost materials, tetraethyl orthosilicate (TEOS) was employed as a precursor to silica. (UV–Vis), FT-IR, XRD, AFM, EDS, TEM, Zeta Potential, VSM, FESEM and VSM were used to characterize the as-prepared silica-coated (Fe3O4@SiO2 CSNPs) and Fe3O4 NPs. UV–Vis exhibits an absorption band in the ultraviolet region at approximately 300 nm in Fe3O4NPs and 310[Formula: see text]nm in Fe3O4@SiO2 CSNPs, this means red shift occurs successively. Results of (XRD) and (EDS) analyses demonstrate that magnetite nanoparticles were effectively coated using this easy process. FESEM and TEM measurements demonstrate that the particle size of iron oxide nanoparticles and iron oxide NPs CSNPs increases before and after coating with spherical particles in form. AFM evaluates surface tension and surface energy. It is found that the surface roughness of magnetite nanoparticles NPs is 49.31[Formula: see text]nm and root mean square (RMS) is 319.8[Formula: see text]nm, whereas in core–shell it is 25.45[Formula: see text]nm and 166.7[Formula: see text]nm, respectively, it was raised in the case of the core–shell. This means decrease in particle size. Magnetic properties from (VSM) test demonstrate that the magnetization of the as-synthesized TEOS-coated magnetite NPs is lower than that of freshly created bare magnetite NPs, demonstrating the formation of Fe3O4@SiO2 CSNPs. The stability was around [Formula: see text][Formula: see text]mV, and the addition of magnetic and optical features improved their biocompatibility. The antibacterial activity of Fe3O4 NPs and Fe3O4@SiO2 CSNPs was investigated using the agar well diffusion method agains t Staphylococcus aureus Gram-positive and Escherichia coli Gram-negative bacteria, which exhibited a wide spectrum of antibacterial potency inhibiting the growth of both Gram-negative (8[Formula: see text]mm, 10[Formula: see text]mm) and Gram-positive (7[Formula: see text]mm, 12[Formula: see text]mm), respectively.

Diagnostic and therapeutic roles of iron oxide nanoparticles in biomedicine.

Nanotechnology changed our understanding of physics and chemics and influenced the biomedical field. Iron oxide nanoparticles (IONs) are one of the first emerging biomedical applications of nanotechnology. The IONs are composed of iron oxide core exhibiting magnetism and coated with biocompatible molecules. The small size, strong magnetism, and biocompatibility of IONs facilitate the application of IONs in the medical imaging field. We listed several clinical available IONs including Resovist (Bayer Schering Pharma, Berlin, Germany) and Feridex intravenous (I.V.)/Endorem as magnetic resonance (MR) contrast agents for liver tumor detection. We also illustrated GastroMARK as a gastrointestinal contrast agent for MR imaging. Recently, IONs named Feraheme for treating iron-deficiency anemia have been approved by the Food and Drug Administration. Moreover, tumor ablation by IONs named NanoTherm has also been discussed. In addition to the clinical application, several potential biomedical applications of IONs including cancer-targeting capability by conjugating IONs with cancer-specific ligands, cell trafficking tools, or tumor ablation agents have also been discussed. With the growing awareness of nanotechnology, further application of IONs is still on the horizon that would shed light on biomedicine.

The size of iron oxide nanoparticles determines their translocation and effects on iron and mineral nutrition of pumpkin (Cucurbita maxima L.)

The ability of nanoparticles (NPs) to migrate in the plant body is an important issue to ensure that the NPs reach the desired tissue and to be able to select the most efficient NPs for agricultural applications. In this study, the size impact of four different iron oxide NPs (8–10, 18–20, 20–40, and 30–50 nm referred as NP10, NP20, NP30, and NP40, respectively) on their translocation in pumpkin was elucidated. To assess the root-to-shoot translocation, phloem sap was examined under transmission electron microscope (TEM). In addition, vibrating sample magnetometer (VSM) and inductively coupled plasma optical emission spectrophotometry (ICP-OES) analyses of stem and leaf tissues were performed to confirm size-dependent translocation. TEM and VSM analyses verified root-to-stem translocation of all tested NPs. The NPs treatment significantly altered the abundances of Mn, Cu, K, P, Al, Mg, and Na in tissues. The iron (Fe) content was abundant in plants treated with NP30 and NP20, and the lowest in plants treated with NP10 and NP40. Together with, only NP30 was found to be significantly translocated to the leaves, where it was 393 mg/kg in DW, about 2.3 times that of control. These findings pointed out the size-dependent translocation of NPs. It seems that biological barriers in the vascular bundle appear to restrict the migration, especially for NPs with an average size of 40 nm and above in pumpkins. These findings are important for selecting the most suitable size of iron oxide NPs for use in agricultural practices.

Biochemical changes of macrophages and U87MG cells occurring as a result of the exposure to iron oxide nanoparticles detected with the Raman microspectroscopy

The core size of iron oxide nanoparticles (IONPs) is a crucial factor defining not only their magnetic properties but also toxicological profile and biocompatibility. On the other hand, particular IONPs may induce different biological response depending on the dose, exposure time, but mainly depending on the examined system. New light on this problem may be shed by the information concerning biomolecular anomalies appearing in various cell lines in response to the action of IONPs with different core diameters and this was accomplished in the present study. Using Raman microscopy we studied the abnormalities in the accumulation of proteins, lipids and organic matter within the nucleus, cytoplasm and cellular membrane of macrophages, HEK293T and U87MG cell line occurring as a result of 24-hour long exposure to PEG-coated magnetite IONPs. The examined nanoparticles had 5, 10 and 30 nm cores and were administered in doses 5 and 25 μg Fe/ml.The obtained results showed significant anomalies in biochemical composition of macrophages and the U87MG cells, but not the HEK293T cells, occurring as a result of exposure to all of the examined nanoparticles. However, IONPs with 10 nm core diminished the accumulation of biomolecules in cells only when they were administered at a larger dose. The Raman spectra recorded for the macrophages subjected to 30 nm IONPs and for the U87MG cells exposed to 5 and 10 nm showed the presence of additional bands in the wavenumber range 1700–2400 cm−1, probably resulting from the appearance of Fe adducts within cells. Our results indicate, moreover, that smaller IONPs may be effectively internalized into the U87MG cells, which points at their diagnostic/therapeutic potential in the case of glioblastoma multiforme.

Green Synthesis of Iron Oxide Nanoparticles Using Hibiscus rosa sinensis Flowers and Their Antibacterial Activity

Iron oxide nanoparticles (α- Fe2O3) were synthesized using an unconventional, eco-friendly technique utilizing a Hibiscus rosa sinensis flower (common name, China rose) extract as a reducer and stabilizer agent. The microwave method was successfully used for the synthesis of iron oxide nanoparticles. Various volume ratios of iron chloride tetrahydrate to the extract were taken and heated by the microwave oven for different periods to optimize iron oxide nanoparticle production. The synthesized iron oxide nanoparticles were characterized using the ultraviolet-visible spectrometer (UV-Vis), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). X-ray diffraction confirmed the formation of α- Fe2O3 nanoparticles (hematite). The average size of iron oxide nanoparticles was found to be 51 nm. The antibacterial activity of the synthesized iron nanoparticles was investigated against different bacteria such as Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, and Escherichia coli. The results showed that the synthesized iron nanoparticles exhibited an inhabitation effect on all studied bacteria.

Synthesis and Characterisation of Iron Oxide Nanoparticles with Tunable Sizes by Hydrothermal Method

The present study investigates the effect of different reaction times on the crystallinity, surface morphology and size of iron oxide nanoparticles. In this synthetic system, aqueous iron (III) nitrate (Fe (NO3)3·9H2O) nonahydrate, provided the iron source and triethylamine was the precipitant and alkaline agent. The as-synthesised iron oxide nanoparticles were characterised by X-ray diffraction (XRD), Rietveld analysis, Scanning Electron Microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Prolonged reaction times indicated the change on nanoparticle shape from elongated nanorods to finally distorted nanocubes. Analysis on the crystallinity of the iron oxide nanoparticles suggest that the samples mainly consist of two phases, which are Goethite (α-FeOOH) and Hematite (α-Fe2O3) respectively.

Hierarchical iron oxide nanocomposite: Bundle-like morphology, magnetic properties and potential biomedical application

Controlled spatial arrangements of superparamagnetic iron oxide nanoparticles (SPIONs) in complex nanostructures determine fine tuning of physico-chemical properties which, in turn, may lead to new practical applications. We report here on newly observed properties of hierarchical SPIONs nanostructure with bundle-like morphology, also known as nanobundles. Colloidal chemical processes and sol-gel synthesis were used for the synthesis of nanobundles, i.e. i) self-assembly of SPIONs into magnetic nanoparticle clusters, ii) their magnetic assembly to the nanochains, and finally iii) formation of bundle-like hierarchical nanostructure. An XRPD measurements show spinel crystal structure of maghemite/magnetite nanoparticles, EDS analysis reveals Fe, Si and O as main elements whereas SEM/TEM analysis show silica-coated magnetic nanoclusters (∼100 nm) and their hierarchical assemblies with bundle-like morphology of ∼8 μm length and ∼1 μm width. TEM analysis revealed core-shell nature of iron oxide nanoparticle clusters with their size of around 80 nm that were coated by an amorphous silica shell with thickness of ∼15 nm. The nanoclusters in the core are constructed of maghemite/magnetite nanoparticle assembly with primary iron oxide nanoparticle size about 10 nm. The magnetization M data as a function of an applied external magnetic field H were successfully fitted by the Langevin function, whence the magnetic moment μp = 19256 μB, and the diameter d = 9.6 nm of nanoparticles were determined. Microsized bundle-like particles are superparamagnetic, magnetically guidable and possess high transverse relaxivity of r2 = 397.8 mM−1s−1. Magnetic properties and such high value of transverse relaxivity holds promise for nanobundles application in MRI imaging (MRI contrast agent), as nanobundles may enhance the magnetic field in their surroundings and enhance proton relaxation processes. Our nanobundles can open new opportunities in the biomedical applications, magnetic separation, photonic crystals and magnetic liquid manipulation and can be inspiration for synthesizing novel self-assembled nanoparticle structures.

Improvement of the saturation magnetization of PEG coated superparamagnetic iron oxide nanoparticles

Polyethylene glycol (PEG) coated iron oxide nanoparticles are of interest because of their distinctive properties and potential applications such as magnetic resonance imaging, magnetic hyperthermia and drug delivery. In this study, PEG coated iron oxide nanoparticles were obtained by a two-step synthesis route including coprecipitation and coating. Different amounts of PEG6000 were used for coating and the effect of PEG amount on the structural and magnetic properties of the nanoparticles was investigated. Crystal structure, surface coating and particle size of the nanoparticles were characterized by X-ray diffraction technique, Fourier transform infrared spectroscopy and transmission electron microscopy. The particle size of iron oxide nanoparticles remained almost constant (7–8 nm) with the increase of PEG amount. It was determined from thermogravimetric analysis that the coating percentage of the nanoparticles steadily increased from 2.6 to 6.9 % with the increase of PEG amount from 5 to 15 g. Magnetic properties of the nanoparticles were studied by vibrating sample magnetometer and all samples were found to be superparamagnetic. PEG coated iron oxide nanoparticles showed higher saturation magnetization, Ms values than the uncoated iron oxide nanoparticles. Also, Ms of the coated nanoparticles increased with the increase of PEG coating and reached a value of 62.4 emu/g showing an increase of 19 % over uncoated iron oxide nanoparticles while maintaining the superparamagnetic behavior. This remarkable rise in the Ms of PEG coated iron oxide nanoparticles may improve the control and delivery of the nanoparticles for potential applications.

Magnetic Field-Induced Self-Assembly of Conjugated Block Copolymers and Nanoparticles at the Air-Water Interface.

Here, we report the magnetic field-induced self-assembly of a conjugated block copolymer, poly(3-hexylthiopene)-block-poly(ethylene glycol) (P3HT-b-PEG), and iron oxide nanoparticles (IONPs) at the air-water interface. Binary self-assembly of P3HT-b-PEG and IONPs at the interface results in nanoparticle-embedded P3HT-b-PEG nanowire arrays with a micrometer-scale domain size. Under the magnetic field, the field-induced magnetic interaction significantly improves the degree of order, generating long-range ordered, direction-controlled nanoarrays of P3HT-b-PEG and IONPs, where IONPs are aligned in the direction of the magnetic field over a sub-millimeter scale. The size of IONPs is an important factor for the formation of an ordered assembly structure at the nanometer scale, as it dictates the magnetic dipole interaction and the entropic interaction between nanoparticles and polymers. The consideration of magnetic dipole interactions suggests that the field-induced self-assembly occurs through the formation of intermediate magnetic subunits composed of short IONP strings along the semirigid P3HT nanowires, which can be aligned through the magnetic interactions, ultimately driving the long-range ordered self-assembly. This study demonstrates for the first time that the magnetic field-induced self-assembly can be used to generate macroscopically ordered polymer films with a nanometer-scale order in low fields.

Magnetic Phase Transition without Heat Treatment of the as-Deposited Iron Oxide Nanoparticulate Films Prepared by Sparking Process under External Magnetic Fields

In this paper, the effect of external magnetic fields on morphology, structural and magnetic properties of the as-deposited iron oxide nanoparticulate (NP) films by the sparking process was investigated. The small and uniform size of iron oxide nanoparticles was deposited on a glass slide substrate by sparking off the iron wires with different external magnetic fields under atmospheric pressure and room temperature. The results showed the roughness and the agglomerated particles of the as-deposited films increased with increasing the external magnetic field due to magnetic and Lorentz forces. The magnetic phase was transformed from maghemite (γ-Fe2O3) to magnetite (Fe3O4) after sparking under the external magnetic field from 0 mT (without field) to 50 and 100 mT. Moreover, the external magnetic field not only affects the magnetic phase transition but also has a direct effect on the energy band gap and magnetization of the films without heat treatment.

Versatile Surface Functionalization of Water-Dispersible Iron Oxide Nanoparticles with Precisely Controlled Sizes.

The synthesis of highly water-dispersible iron oxide nanoparticles with surface functional groups and precisely controlled sizes is essential for biomedical application. In this paper, we report a one-pot strategy for versatile surface functionalization. The iron oxide nanoparticles are first synthesized by thermal decomposition of iron(III) acetylacetonate (Fe(acac)3) in diethylene glycol (DEG), and their surfaces are modified by adding the surface ligands at the end of the reaction. The size of iron oxide nanoparticles can be precisely controlled in nanometer scale by continuous growth. This facile synthesis method enables the surface modification with different coating materials such as dopamine (DOPA), polyethylene glycol with thiol end group (thiol-PEG), and poly(acrylic acid) (PAA) onto the iron oxide nanoparticles, introducing new surface functionalities for future biomedical application. From transmission electron microscopy (TEM) and X-ray diffraction (XRD), the morphology and crystal structure are not changed during surface functionalization. The attachment of surface ligands is studied by Fourier transform infrared spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). The surface functional groups are confirmed by X-ray Photoelectron Spectroscopy (XPS). In correlation with the change of hydrodynamic size, PAA coated nanoparticles are found to exhibit outstanding stability in aqueous solution. Furthermore, we demonstrate that the functional groups are available for conjugating with other molecules such as fluorescent dye, showing potential biological applications. Lastly, the magnetic resonance phantom studies demonstrate that iron oxide nanoparticles with PAA coating can be used as T1 and T2 dual-modality contrast agents. Both r1 and r2 relaxivities significantly increase after surface functionalization with PAA, indicating improved sensitivity.

Iron oxide @ gold nanoparticles: Synthesis, properties and potential use as anode materials for lithium-ion batteries

This paper presents the results of the study of iron oxide/gold composites using powder X-ray diffractometry (XRD), scanning (SEM) and transmission (TEM) electron microscopy, laser diffraction analysis (LDA) and Mössbauer spectroscopy (MS), as well as the results of their electrochemical tests as an anode material for lithium-ion batteries. It is established that as a result of using the two-stage synthesis method, the obtained composites are iron oxide@gold core-shell nanoparticles (NPs). After the first stage of chemical synthesis the initial non-gold-coated iron oxide NPs were the magnetite (Fe3O4)/maghemite (γ-Fe2O3) mixtures (molar fraction of maghemite ∼ 0.49) and/or the magnetite-maghemite solid solutions (Fe3–γO4) (γ∼0.17). After the second stage the coating of iron oxides with gold the nanoparticle cores were mainly maghemite. SEM, TEM, XRD and LDA measurements revealed that the average size of iron oxide NPs is ∼18 nm, and iron oxide@gold NPs is ∼25 nm. The Mössbauer spectroscopy allowed us to determine the fraction of Fe atoms in the form of maghemite in initial non-gold-coated iron oxide NPs (0.47 ± 0.02) and in iron oxide@gold NPs (0.97 ± 0.03), as well as to estimate the size of initial iron oxide NPs (16.4 ± 0.4 nm) and magnetic nuclei of iron oxide@gold (18.1 ± 0.9 nm) NPs. The results of electrochemical measurements showed that iron oxide@gold core-shell nanoparticles can be used as an anode material for lithium-ion batteries.

Low cost and efficient synthesis of magnetic iron oxide/activated sericite nanocomposites for rapid removal of methylene blue and crystal violet dyes

Activated sericite was used as a solid matrix for control over the size of iron oxide nanoparticles (NPs). The activation of sericite was achieved by undergoing thermal, acid and salt treatments. Different weight ratios (w.r.) of iron oxide to activated sericite were prepared by varying the amount of iron oxide. X-ray diffraction (XRD) patterns illustrated a decrease in the intensity of sericite peaks by increasing the amount of iron oxide. High resolution-transmission electron microscopy (HR-TEM) analysis showed the formation of highly distributed quasi-spherical iron oxide NPs with average diameter of about 3.56–7.78 nm. The formation of mesoporous iron oxide NPs on the surface and edge of the activated sericite surface were also observed under Field emission scanning electron microscopy (FESEM). Vibration sample magnetometer (VSM) measurement revealed the nanocomposites (NCs) with saturation magnetization of about 2.17–8.12 emu·g−1. Brunauer-Emmett-Teller (BET) surface area analysis revealed the specific surface area of NCs between 79.4 and 161.5 m2·g−1. Fourier transform infrared (FTIR) spectra showed non-bond chemical interaction between the iron oxide and rigid silicate layers. Ultraviolet–visible (UV–vis) diffuse reflectance spectroscopy confirms that the material has band gap energy of about 2.55 eV. The NC with w.r. of 1:3 (iron oxide to activated sericite) showed the best performance with high specific surface area and sufficient magnetization for easy magnetic separation. The selected NC showed maximum removal efficiency over 99% for methylene blue and crystal violet dyes within 20 min.

Investigating the toxic effects induced by iron oxide nanoparticles on neuroblastoma cell line: an integrative study combining cytotoxic, genotoxic and proteomic tools

Nanomaterials have gained much attention for their use and benefit in several fields. Iron Oxide Nanoparticles (IONPs) have been used in Biomedicine as contrast agents for imaging cancer cells. However, several studies reported the potential toxicity of those nanoparticles in different models, especially in cells. Therefore, in our present study, we investigated the effects of IONPs on the SH-SY5Y neuroblastoma cell line. We carried out cytotoxic and genotoxic studies to evaluate the phenotypic effects, and proteomic investigation to evaluate the molecular effects and the mechanisms by which this kind of NPs could induce toxicity. Our results showed that the use of three different sizes of IONPs (14, 22 and 30 nm) induced cell detachment, cell morphological changes, size, and concentration-dependent IONP internalization and cell mortality. IONPs induced slight genotoxic damage assayed by modified comet assay without affecting cell cycle, mitochondrial function, membrane integrity, intracellular calcium level, and without inducing ROS generation. All the studies were performed to compare also the effects of IONPs to the ferric iron by incubating cells with equivalent concentration of FeCl3. In all tests, the NPs exhibited more toxicity than the ferric iron. The proteomic analysis followed by gene ontology and pathway analysis evidenced the effects of IONPs on cytoskeleton, cell apoptosis, and cancer development. Our findings provided more information about IONP effects on human cells and especially on cancer cell line.

Genotoxic Assessment of Different Sizes of Iron Oxide Nanoparticles and Ionic Iron in Earthworm (Eisenia hortensis) Coelomocytes by Comet Assay and Micronucleus Test.

The current study was designed to evaluate genotoxicity of different sizes of iron oxide nanoparticles (IONPs) and ionic iron using coelomocytes of the earthworms Eisenia hortensis. Earthworms were exposed to different series of IONPs and ionic iron concentrations to find the respective LC50 of the chosen chemicals. LC50 for < 50, <100nm and the ionic iron of IONPs were 500, 200, 250µg/mL respectively. Concentrations of LC50/2 (250, 100, 125µg/mL for < 50, <100nm and the ionic iron respectively) and LC50 for 48 h were used to perform the comet assay and micronucleus test. Statistically significant (p < 0.05) increase in DNA and chromosomal damage was observed for all sizes of IONPs and ionic iron. In the comet assay system, the greatest genotoxicity was observed in the treatments with < 100nm IONPs, whereas the greatest numbers of micronuclei and binucleate cells were observed in the treatments with ionic iron. It was concluded that different types of nanoparticles (i.e. sizes, shapes) may have different genotoxic potencies in different assays with E. hortensis earthworms.

Cytotoxicity assay of plant-mediated synthesized iron oxide nanoparticles using Juglans regia green husk extract

Synthesis of iron oxide nanoparticles has attracted increasing interest due to their importance in biomedical and technological applications. To investigate the ability of Juglans regia (J. regia) green husk extract in iron oxide nanoparticles size control, they were synthesized through co-precipitation method with J. regia extract and without it. For both tests, other experimental conditions were same. According to High-resolution transmission electron microscopy, the mean diameter and standard deviation of iron oxide nanoparticles and J. regia/iron oxide nanoparticles synthesized using co-precipitation method were 12.60 ± 2.87 and 5.77 ± 1.66 nm respectively. These results showed that J. regia/iron oxide nanoparticles synthesized using extract have a smaller size than nanoparticles fabricated by co-precipitation method; moreover, green husk extract plays the main role as size control. The obtained results of Powder X-ray diffraction (PXRD), High resolution transmission electron microscopy (HR-TEM), Field emission scanning electron microscopy (FESEM), and Energy dispersive X-ray (EDX) are in good agreement with each other and confirm the high purity of fabricated magnetic nanoparticles using J. regia extract. Vibrating sample magnetometer (VSM) revealed that the J. regia/iron oxide nanoparticles due to their proper magnetic properties have high saturation magnetization and low coercivity. According to FTIR spectrum, the J. regia would be coated on the iron oxide nanoparticles surface in a successful manner. The non-toxic effect of J. regia/iron oxide nanoparticles concentration below 1000 µg/ml was observed in the studies of in vitro cytotoxicity on normal and cancerous cell lines, respectively. The dose-dependent toxicity made it a suitable candidate for various medical applications.