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Magnetite and gallium substituted cuboferrites with a composition of Ga x Fe 3-x O 4 (0 ≤ x ≤ 1.4) were fabricated by thermal decomposition from acetylacetonate salts. The effect of Ga 3+ cation substitution on the structural and thermomagnetic behavior of 4-12 nm sized core-shell particles was explored by X-ray and neutron diffraction, small angle neutron scattering, transmission electron microscopy, Mössbauer spectroscopy, and calorimetric measurements. Superparamagnetic (SPM) behavior and thermal capacity against increasing gallium concentration in nanoferrites were revealed. The highest heat capacity typical for Fe 3 O 4 @Ga 0.6 Fe 2.4 O 4 and Ga 0.6 Fe 2.4 O 4 @Fe 3 O 4 is accompanied by a slight stimulation of fibroblast culture growth and inhibition of HeLa cell growth. The observed effect is concentration dependent in the range of 0.01-0.1 mg/mL and particles of Ga 0.6 Fe 2.4 O 4 @Fe 3 O 4 design have a greater effect on cells. Observed magnetic heat properties, as well as interactions with tumor and healthy cells, provide a basis for further biomedical research to use the proposed nanoparticle systems in cancer thermotherapy (magnetic hyperthermia).

The use of nanotechnology in the food industry raises uncertainty in many respects. For years, achievements of nanotechnology have been applied mainly in biomedicine and computer science, but recently it has also been used in the food industry. Due to the extremely small (nano) scale, the properties and behavior of nanomaterials may differ from their macroscopic counterparts. They can be used as biosensors to detect reagents or microorganisms, monitor bacterial growth conditions, increase food durability e.g. when placed in food packaging, reducing the amount of certain ingredients without changing the consistency of the product (research on fat substitutes is underway), improve the taste of food, make some nutrients get better absorbed by the body, etc . There are companies on the market that are already introducing nanoparticles into the economy to improve their functionality, e.g. baby feeding bottles. This review focuses on the use of nanoparticles in the food industry, both organic (chitosan, cellulose, proteins) and inorganic (silver, iron, zinc oxide, titanium oxide, etc .). The use of nanomaterials in food production requires compliance with all legal requirements regarding the safety and quantity of nano-processed food products described in this review. In the future, new methods of testing nanoparticles should be developed that would ensure the effectiveness of compounds subjected to, for example, nano-encapsulation, i.e. whether the encapsulation process had a positive impact on the specific properties of these compounds. Nanotechnology has revolutionized our approach towards food engineering (from production to processing), food storage and the creation of new materials and products, and the search for new product applications.

A proper understanding of silver (Ag) nanoparticles properties is fundamental for developing new antimicrobial agents. In this study, Ag nanoparticles were obtained by green synthesis methods using natural reducing agents present in extracts of apples, oranges, potatoes, red pepper, white onion, garlic and radish. The antimicrobial properties of respective nanoparticles, expressed as the minimum inhibitory concentration, were assessed against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Candida krusei. Characterization of Ag nanoparticles was done with the application of transmission electron microscopy, X-ray diffraction and UV-vis spectroscopy. The obtained results led to the conclusions that in each extract (pH from 2.1 to 6.2) were obtained specific particles (size from 9 to 30 ± 2 nm) with different antimicrobial activity. Our study indicates that plant extracts gives the Ag nanoparticles specific properties, yet the best antimicrobial properties show nanoparticles obtained in the presence of potato extract., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This study investigated the methods of preparation of zinc oxide-polypropylene nanocomposites and their antibacterial properties. Seven solutions with ZnO nanoparticles or zinc ions were formulated as a PP additive. Two methods of ZnO NPs syntheses were carried out: (1) a modified hydrothermal method where a water solution of zinc acetate dihydrate, PEI, and ammonia were mixed with a final pH 11; (2) a thermal decomposition of a water solution of zinc acetate in the presence of PEI and ammonia using a two-screw extruder. During the experiments, the influence of various amounts of particle stabilizer, heating of the solutions, and the temperatures of the syntheses were examined. As a result, the simultaneous crystallization of ZnO in the extrusion process confirmed this method's attractiveness from the application point of view. Fabricated PP-ZnO composite shows antibacterial properties against Staphylococcus aureus , Escherichia coli , and Klebsiella pneumoniae .

The aim of the study is an ecotoxicological assessment of magnetite iron oxide-based nanoparticles (NPs), which have risen in popularity in the last decade, on selected terrestrial and aquatic organisms from various levels of the food chain. In the presented study various organisms, from both the terrestrial and aquatic environment, were used as targets for the assessment of NPs ecotoxicity. Plants (radish, oat), marine bacteria (A. fischeri) and crustacean (H. incongruens) were used to represent producers, decomposers, and consumers, respectively. It was found that examined NPs were harmful (to a different degree) to biota from three different trophic levels. Physicochemical characterization (size/morphology, crystallinity, composition, and magnetic properties) of the tested nanoparticles was performed by: transmission electron microscopy, X-ray diffraction, energy dispersive spectroscopy, and Mossbauer spectroscopy, respectively. Phytotoxicity was evaluated according to the OECD 208 Guideline, while acute and chronic toxicity of NPs was conducted using bioassays employing bacteria and crustacea, respectively. The phytotoxicity of all investigated iron oxide-based NPs was dependent on concentration and type of NPs formulation and was measured via biomass, seed germination, root length, shoot height, and content of plant pigments. Increasing the concentration of NPs increased phytotoxicity and mortality of aquatic organisms. Ecotoxicity of iron oxide/silver was dependent on the size and content of silver. Iron oxide NPs coated with nanosilver in a percentage ratio of 69/31 were found to be the most toxic on tested terrestrial and aquatic biota., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Magnetic hyperthermia (MHT) is in the spotlight of nanomedical research for the treatment of cancer employing magnetic iron oxide nanoparticles and their intrinsic capability for heat dissipation under an alternating magnetic field (AMF). Herein we focus on the synthesis of iron oxide nanoflowers (Nfs) of different sizes (15 and 35 nm) and coatings (bare, citrate, and Rhodamine B) while comparing their physicochemical and magnetothermal properties. We encapsulated colloidally stable citrate coated Nfs, of both sizes, in thermosensitive liposomes via extrusion, and RhB was loaded in the lipid bilayer. All formulations proved hemocompatible and cytocompatible. We found that 35 nm Nfs, at lower concentrations than 15 nm Nfs, served better as nanoheaters for magnetic hyperthermia applications. In vitro, magnetic hyperthermia results showed promising therapeutic and imaging potential for RhB loaded magnetoliposomes containing 35 nm Nfs against LLC and CULA cell lines of lung adenocarcinoma., (© 2022. The Author(s).)

This paper refers to research based on tests completed on the adsorption of heavy metal ions (Pb 2+ , Cu 2+ , Cd 2+ ) from selected natural liquid samples such as apple, tomato, and potato juices using surface-functionalized Mn ferrite nanoparticles (Mn 0.2 Fe 2.8 O 4 ). To determine the most efficient adsorption conditions of these heavy metals, the nanoparticles' surfaces were modified with five different ligands (phthalic anhydride, succinic anhydride, acetic anhydride, 3-phosphonopropionic acid, and 16-phosphonohexadecanoic acid). To evaluate the success of the adsorption process, the resultant liquid samples were examined for the amount of residuals using the flame atomic absorption spectroscopy method. The Mn ferrite particles selected for these tests were first characterized physicochemically by the following methods: transmission electron microscopy, scanning electron microscopy, X-ray diffraction, IR spectroscopy, Mössbauer spectroscopy.

In the presented paper, studies of magnetite nanoparticle stability in selected environmental solutions are reported. The durability tests were performed in four types of liquids: treated and untreated wastewater, river water, and commercial milk (0.5% fat). Nanoparticles before and after deposition in the testing conditions were measured by transmission electron microscopy, X-ray diffraction, infrared spectroscopy, and Mössbauer spectroscopy. The amount of Fe atoms transferred into the solutions was estimated on the basis of flame atomic absorption spectroscopy. The analysis of the obtained results shows good stability of the tested nanoparticles in all water solutions. They do not change their structure or magnetic properties significantly, which makes them a good candidate to be used as, for example, detectors of specific compounds or heavy metals. On the other hand, studies show that particles are stable in environmental conditions for a long period of time in an unchanged form, which can cause their accumulation; therefore, they may be hazardous to living organisms.

Over the past few decades nanotechnology has paved its way into cancer treatment procedures with the use of nanoparticles (NPs) for contrast media and therapeutic agents. Iron based NPs are the most investigated since they can be used for drug delivery, imaging and when magnetically activate employed as local heat sources in cancer hyperthermia. In this work, was performed synthesis, characterization and biological evaluation of different types of iron oxide nanoparticles (mNPs'), as promising material for tumor hyperthermia. The surface of mNPs' has modified with inorganic stabilizing agents to particularly improve characteristics such as their magnetic properties, colloidal stability and biocompatibility. The successful coating of mNPs' was confirmed by morphological and structural characterization by transmission electron microscopy (TEM) and Fourier-Transform Infra-Red spectroscopy (FT-IR), while their hydrodynamic diameter was studied by using Dynamic light scattering (DLS). X-ray Diffraction (XRD) proved that the crystallite phase of mNPs' is the same with the pattern of magnetite. Superparamagnetic behavior and mNPs' response under the application of alternating magnetic field (AMF) were also thoroughly investigated and showed good heating efficiency in magnetic hyperthermia experiments. The contrast ability in magnetic resonance imaging (MRI) is also discussed indicating that mNPs are negative MRI contrast types. Nonetheless the effects of mNPs on cell viability was performed by MTT on human keratinocytes, human embryonic kidney cells, endothelial cells and by hemolytic assay on erythrocytes. In healthy keratinocytes wound healing assay in different time intervals was performed, assessing both the cell migration and wound closure. Endothelial cells have also been studied in functional activity performing capillary morphogenesis. In vitro studies showed that mNPs are safely taken by the healthy cells and do not interfere with the biological processes such as cell migration and motility., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In this paper, a series of experiments are reported where ferrite nanoparticles were synthesized with different substitution percentages (5, 10, 15, or 20%) of Fe 2+ by Co 2+ , Mn 2+ , or Ni 2+ ions. Afterwards, the prepared nanoparticles were thermally treated between 50 and 500 °C in air for 24 h in order to observe how doping influences the oxidation process induced by temperature elevation and access to O 2 . Nanoparticles were imaged before and after thermal treatment by transmission electron microscopy and were analyzed by X-ray diffraction, vibrating sample magnetometry, and Mössbauer spectroscopy. Presented studies reveal that the amount and kind of doped transition metals (of replaced Fe 2+ ) strongly affect the oxidation process of ferrite nanoparticles, which can govern the application possibility. Each transition element suppresses the oxidation process in comparison to pure Fe-oxides, with the highest impact seen with Ni 2+ .

This study shows the influence of selected nonstandard surfactants on the growth and properties of magnetite nanoparticles. Particles were obtained using thermally decomposed iron (III) acetylacetonate in an organic environment. For synthesis, three different concentrations (4, 8, and 16 mmol) of tested surfactants were used. Five types of each long-chain carboxylic acid and amines were selected for stabilization of nanoparticles. Nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, and infrared spectroscopy. Magnetic properties of the nanoparticles were tested by conventional room temperature Mössbauer spectroscopy with and without external magnetic field. TEM images clearly showed that application of tertiary amines causes the nanoparticles to form nanoflowers, in contrast to other compounds, which do not show such growth. Influence of surfactant amount on growth regime depends on the nature of the substances. Mössbauer spectroscopy confirms differences in magnetic core composition as a result of the surfactant amount present in synthetic procedure.

The electrodeposition of FeNi alloy films was performed galvanostatically in the sulfate solution (Fe 2+ /Ni 2+ mass ratio 1:2) in order investigate their co-deposition mechanism. The FeNi layers were deposited at variable substrates (copper, brass, silver) under the same chemical (electrolyte composition) and electric plating (current density value) conditions. After applying various time, substrates and external magnetic field orientation, the quality of the obtained film was examined. The surface morphology and crystallographic texture variation were investigated by the Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Wavelength Dispersive X-ray Fluorescence (WDXRF) and Laser Confocal Scanning Microscope (LCSM). The anomalous co-deposition of iron group metals is evidently dependent on the substrate.

In this work, we analyze artificial heavy-metal solutions with ferrite nanoparticles. Measurements of adsorption effectiveness of different kinds of particles, pure magnetite or magnetite doped with calcium, cobalt, manganese, or nickel ions, were carried out. A dependence of the adsorption efficiency on the composition of the inorganic core has been observed. Ferrites surfaces were modified by phthalic anhydride (PA), succinic anhydride (SA), acetic anhydride (AA), 3-phosphonopropionic acid (3-PPA), or 16-phosphohexadecanoic acid (16-PHDA) to compare the adsorption capability of the heavy metals Cd, Cu and Pb. The obtained nanoparticles were structurally characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Mössbauer spectroscopy. The amounts of Cd, Cu and Pb were measured out by atomic absorption spectroscopy (AAS) and energy dispersive X-ray (EDX) as comparative techniques. The performed study shows that SA linker appears to be the most effective in the adsorption of heavy metals. Moreover, regarding the influence of the composition of the inorganic core on the detection ability, the most effective ferrite Mn 0.5 Fe 2.5 O 4 was selected for discussion. The highest heavy-metal adsorption capability and universality was observed for SA as a surface modifier.

Ferrite nanoparticles with nominal composition Me 0.5 Fe 2.5 O 4 (Me = Co, Fe, Ni or Mn) have been successfully prepared by the wet chemical method. The obtained particles have a mean diameter of 11-16 ± 2 nm and were modified to improve their magnetic properties and chemical activity. The surface of the pristine nanoparticles was functionalized afterwards with -COOH and -NH 2 groups to obtain a bioactive layer. To achieve our goal, two different modification approaches were realized. In the first one, glutaraldehyde was attached to the nanoparticles as a linker. In the second one, direct bonding of such nanoparticles with a bioparticle was studied. In subsequent steps, the nanoparticles were immobilized with enzymes such as albumin, glucose oxidase, lipase and trypsin as a test bioparticles. The characterization of the nanoparticles was acheived by transmission electron microscopy, X-ray diffraction, energy dispersive X-ray and Mössbauer spectroscopy. The effect of the obtained biocomposites was monitored by Fourier transform infrared spectroscopy. The obtained results show that in some cases the use of glutaraldehyde was crucial (albumin).

One of the most popular nuclear probes, 57 Fe is used for the investigation of orientations of hyperfine fields and also for the determination of other important properties. In particular, the orientation of iron magnetic moments can be unambiguously determined, including its signs. Experiments with polarized radiation are presented with regard to selected systems. Orientation of electric field gradient is used for acquiring information about the shape of the texture-free spectra. Applications on the analysis of iron-based superconductors are presented., (Published by Elsevier B.V.)

This paper presents the results of a thermal treatment process for magnetite nanoparticles in the temperature range of 50-500 °C. The tested magnetite nanoparticles were synthesized using three different methods that resulted in nanoparticles with different surface characteristics and crystallinity, which in turn, was reflected in their thermal durability. The particles were obtained by coprecipitation from Fe chlorides and decomposition of an Fe(acac)3 complex with and without a core-shell structure. Three types of ferrite nanoparticles were produced and their thermal stability properties were compared. In this study, two sets of unmodified magnetite nanoparticles were used where crystallinity was as determinant of the series. For the third type of particles, a Ag shell was added. By comparing the coated and uncoated particles, the influence of the metallic layer on the thermal stability of the nanoparticles was tested. Before and after heat treatment, the nanoparticles were examined using transmission electron microscopy, IR spectroscopy, differential scanning calorimetry, X-ray diffraction and Mössbauer spectroscopy. Based on the obtained results, it was observed that the fabrication methods determine, to some extent, the sensitivity of the nanoparticles to external factors.

Although melanin is known for protecting living organisms from harmful physical and chemical factors, its synthesis is rarely observed among endospore-forming Bacillus cereus sensu lato. Here, for the first time, we reported that psychrotolerant Bacillus weihenstephanensis from Northeastern Poland can produce melanin-like pigment. We assessed physicochemical properties of the pigment and the mechanism of its synthesis in relation to B. weihenstephanensis genotypic and phenotypic characteristics. Electron paramagnetic resonance (EPR) spectroscopy displayed a stable free radical signal of the pigment from environmental isolates which are consistent with the commercial melanin. Fourier transform infrared spectroscopy (FT-IR) and physicochemical tests indicated the phenolic character of the pigment. Several biochemical tests showed that melanin-like pigment synthesis by B. weihenstephanensis was associated with laccase activity. The presence of the gene encoding laccase was confirmed by the next generation whole genome sequencing of one B. weihenstephanensis strain. Biochemical (API 20E and 50CHB tests) and genetic (Multi-locus Sequence Typing, 16S rRNA sequencing, and Pulsed-Field Gel Electrophoresis) characterization of the isolates revealed their close relation to the psychrotrophic B. weihenstephanensis DSMZ 11821 reference strain. The ability to synthesize melanin-like pigment by soil B. weihenstephanensis isolates and their psychrotrophic character seemed to be a local adaptation to a specific niche. Detailed genetic and biochemical analyses of melanin-positive environmental B. weihenstephanensis strains shed some light on the evolution and ecological adaptation of these bacteria. Moreover, our study raised new biotechnological possibilities for the use of water-soluble melanin-like pigment naturally produced by B. weihenstephanensis as an alternative to commercial non-soluble pigment.

Superparamagnetic iron oxide nanoparticles (SPIONs) and their derivatives (aminosilane and gold-coated) have been widely investigated in numerous medical applications, including their potential to act as antibacterial drug carriers that may penetrate into bacteria cells and biofilm mass. Pseudomonas aeruginosa is a frequent cause of infection in hospitalized patients, and significant numbers of currently isolated clinical strains are resistant to standard antibiotic therapy. Here we describe the impact of three types of SPIONs on the growth of P. aeruginosa during long-term bacterial culture. Their size, structure, and physicochemical properties were determined using transmission electron microscopy, X-ray diffraction analysis, and Fourier transform infrared spectroscopy. We observed significant inhibition of P. aeruginosa growth in bacterial cultures continued over 96 hours in the presence of gold-functionalized nanoparticles (Fe₃O₄@Au). At the 48-hour time point, growth of P. aeruginosa, as assessed by the number of colonies grown from treated samples, showed the highest inhibition (decreased by 40%). These data provide strong evidence that Fe₃O₄@Au can dramatically reduce growth of P. aeruginosa and provide a platform for further study of the antibacterial activity of this nanomaterial.

In the paper, we present three different types of magnetite nanoparticles which were prepared from co-percipitation of iron (II) and (III) chlorides in aqueous solution with and without SiO2 and from thermal decomposition of iron (III) acetylacetonate in nonaqeous solutions. The obtained core-shell nanoparticles were tested in respect of their stability in distilled water, 10% acetic acid, 0.01 M citric acid, 0.9% NaCl and commercial white wine (12% of alcohol). Changes of the nanoparticles were examined by infrared spectroscopy, atomic absorption spectroscopy, transmission electron microscopy, X-ray diffraction and differential scanning calorimetry methods. Modification of magnetic properties was measured by Mössbauer spectroscopy., (Copyright © 2013 Elsevier B.V. All rights reserved.)

In the presented study, efforts have been undertaken to obtain the magnetic nanowires of multisegmental internal structure by AC and DC electrodeposition methods. The core-shell nanowires were obtained by wetting chemical deposition followed by thermal crystallization and electrodeposition. Such nanowires were tested to obtain functionalization by organophosphorous compounds and finally immobilize enzymes like trypsin. All obtained nanostructures were tested by X-ray diffraction, infrared spectroscopy and transmission electron microscopy., (Copyright © 2013 Elsevier B.V. All rights reserved.)

In this work magnetite nanoparticles covered by gold and silver shell were obtained. Analyzed particles were modified by two kinds of organophosphorous compounds: 3-phosphonopropionic acid and 16-phosphonohexadecanoic acid. Enzyme immobilization on particles modified in such a way was tested. The crystal structure of obtained nanoparticles was characterized by transmission electron microscopy and X-ray diffraction. Possible changes on the surfaces were analyzed by the use of infrared spectroscopy. Magnetic properties were studied by Mössbauer spectroscopy., (Copyright © 2013 Elsevier B.V. All rights reserved.)

X-ray absorption, Mössbauer, and Raman spectroscopy were combined to determine the local environment of iron ions in acetone based solutions of FeCl2. It is shown that part of the Fe(II) ions change their oxidation state, accompanied by symmetry change from octahedral Fe(H2O)6(2+) to tetrahedral [FeCl4](-) at large acetone concentrations. The ratio of Fe(II)/Fe(III) determined by Mössbauer spectroscopy agrees well with that determined by the X-ray absorption studies. Raman measurements confirm quantitative estimations of [FeCl4](-) species in acetone rich solutions.

This study presents modification of magnetite nanoparticles and fullerene for biocompatibility. It show also specific fabrication of magnetite-carbon nanocomposite with immobilized biomolecule. The composites were created by joining individual components step-by-step manner (fullerene to magnetite and glucose oxidase or glucose oxidase to magnetite and fullerene). The resulting nanocomposites were characterized by infrared spectroscopy (IR) and transmission electron microscopy (TEM).

Small carbon nano-onions (CNOs, 6-8 shells) were prepared in high yield and functionalized with carboxylic groups by chemical oxidation. After functionalization these nanostructures were soluble in aqueous solutions. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2 tetrazolium (MTS) tests showed excellent cytocompatibility of all CNOs analyzed at 30 and 300 microg mL(-1), so these carbon nanostructures can be safely used for biological applications. The first covalent functionalization of oxidized CNOs (ox-CNOs) with biomolecules, by using biotin-avidin interactions is reported here. Multilayers were prepared on a gold surface by layer-by-layer assembly and the process was monitored by surface plasmon resonance (SPR) spectroscopy and atomic force microscopy (AFM). Covalent binding of molecules to the short amine-terminated organosulfur monolayers was assessed by Fourier transform infrared spectroscopy using total attenuated reflactance mode (FT-IR/HATR).