Evaluation of antibacterial property of hydroxyapatite and zirconium oxide‐modificated magnetic nanoparticles against Staphylococcus aureus and Escherichia coli

In the first section of this research, superparamagnetic nanoparticles (NPs) (Fe₃ O₄) modified with hydroxyapatite (HAP) and zirconium oxide (ZrO₂) and thereby Fe₃ O₄ /HAP and Fe₃ O₄ /ZrO₂ NPs were synthesised through co‐precipitation method. Then Fe₃ O₄ /HAP and Fe₃ O₄ /ZrO₂ NPs characterised with various techniques such as X‐ray photoelectron spectroscopy, X‐ray diffraction, scanning electron microscopy, energy dispersive X‐ray analysis, Brunauer–Emmett–Teller, Fourier transform infrared, and vibrating sample magnetometer. Observed results confirmed the successful synthesis of desired NPs. In the second section, the antibacterial activity of synthesised magnetic NPs (MNPs) was investigated. This investigation performed with multiple microbial cultivations on the two bacteria; Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Obtained results proved that although both MNPs have good antibacterial properties, however, Fe₃ O₄ /HAP NP has greater antibacterial performance than the other. Based on minimum inhibitory concentration and minimum bactericidal concentration evaluations, S. aureus bacteria are more sensitive to both NPs. These nanocomposites combine the advantages of MNP and antibacterial effects, with distinctive merits including easy preparation, high inactivation capacity, and easy isolation from sample solutions by the application of an external magnetic field.Inspec keywords: nanocomposites, X‐ray chemical analysis, microorganisms, magnetic particles, scanning electron microscopy, precipitation (physical chemistry), nanomagnetics, X‐ray diffraction, X‐ray photoelectron spectra, nanoparticles, superparamagnetism, iron compounds, antibacterial activity, biomedical materials, nanomedicine, calcium compounds, nanofabrication, Fourier transform infrared spectra, magnetometers, zirconium compoundsOther keywords: antibacterial effects, antibacterial property, superparamagnetic nanoparticles, X‐ray photoelectron spectroscopy, X‐ray diffraction, X‐ray analysis, antibacterial activity, bactericidal concentration, S. aureus bacteria, Staphylococcus aureus, Escherichia coli, hydroxyapatite, coprecipitation method, scanning electron microscopy, energy dispersive X‐ray analysis, Brunauer‐Emmett‐Teller method, Fourier transform infrared spectroscopy, vibrating sample magnetometer, microbial cultivations, nanocomposites     

Fabrication and characterisation of super‐paramagnetic responsive PLGA–gelatine–magnetite scaffolds with the unidirectional porous structure: a physicochemical,mechanical, and in vitro evaluation

Architecture and composition of Scaffolds are influential factors in the regeneration of defects. Herein, synthesised iron oxide (magnetite) nanoparticles (MNPs) by co‐precipitation technique were evenly distributed in polylactic‐co‐glycolic acid (PLGA)–gelatine Scaffolds. Hybrid structures were fabricated by freeze‐casting method to the creation of a matrix with tunable pores. The synthesised MNPs were characterised by transmission electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction spectroscopy, and vibrating sample magnetometer analysis. Scanning electron microscopy micrographs of porous Scaffolds confirmed the formation of unidirectional microstructure, so that pore size measurement indicated the orientation of pores in the direction of solvent solidification. The addition of MNPs to the PLGA–gelatine Scaffolds had no particular effect on the morphology of the pores, but reduced slightly pore size distribution. The MNPs contained constructs demonstrated increased mechanical strength, but a reduced absorption capacity and biodegradation ratio. Stability of the MNPs and lack of iron release was the point of strength in this investigation and were determined by atomic absorption spectroscopy. The evolution of rat bone marrow mesenchymal stem cells performance on the hybrid structure under a static magnetic field indicated the potential of super‐paramagnetic constructs for further pre‐clinical and clinical studies in the field of neural regeneration.Inspec keywords: transmission electron microscopy, biodegradable materials, nanofabrication, freezing, mechanical strength, tissue engineering, X‐ray diffraction, cellular biophysics, precipitation (physical chemistry), biomedical materials, iron compounds, porosity, scanning electron microscopy, atomic absorption spectroscopy, gelatin, nanoparticles, porous materials, bone, nanocomposites, Fourier transform infrared spectraOther keywords: unidirectional microstructure, pore size measurement, mechanical strength, atomic absorption spectroscopy, hybrid structure, super‐paramagnetic responsive PLGA–gelatine–magnetite scaffolds, unidirectional porous structure, tissue engineering Scaffolds, co‐precipitation technique, polylactic‐co‐glycolic acid–gelatine Scaffolds, freeze‐casting method, transmission electron microscopy, Fourier‐transform infrared spectroscopy, X‐ray diffraction spectroscopy, scanning electron microscopy micrographs, pore size distribution, absorption capacity, iron oxide nanoparticles, Fe₃ O₄      

Solvothermal‐assisted green synthesis of hybrid Chi‐Fe3 O4 nanocomposites: a potential antibacterial and antibiofilm material

In this present study, a hybrid Chi‐Fe₃ O₄ was prepared, characterised and evaluated for its antibacterial and antibiofilm potential against Staphylococcus aureus and Staphylococcus marcescens bacterial pathogens. Intense peak around 260 nm in the ultraviolet–visible spectrum specify the formation of magnetite nanoparticles. Spherical‐shaped particles with less agglomeration and particle size distribution of 3.78–46.40 nm were observed using transmission electron microscopy analysis and strong interaction of chitosan with the surface of magnetite nanoparticles was studied using field emission scanning microscopy (FESEM). X‐ray diffraction analysis exhibited the polycrystalline and spinel structure configuration of the nanocomposite. Presence of Fe and O, C and Cl elements were confirmed using energy dispersive X‐ray microanalysis. Fourier transform infrared spectroscopic analysis showed the reduction and formation of Chi‐Fe₃ O₄ nanocomposite. The antibacterial activity by deformation of the bacterial cell walls on treatment with Chi‐Fe₃ O₄ nanocomposite and its interaction was visualised using FESEM and the antibiofilm activity was determined using antibiofilm assay. In conclusion, this present study shows the green synthesis of Chi‐Fe₃ O₄ nanocomposite and evaluation of its antibacterial and antibiofilm potential, proving its significance in medical and biological applicationsInspec keywords: visible spectra, particle size, magnetic particles, nanocomposites, nanoparticles, X‐ray diffraction, nanofabrication, transmission electron microscopy, X‐ray chemical analysis, nanomagnetics, microorganisms, antibacterial activity, iron compounds, ultraviolet spectra, biomedical materials, field emission scanning electron microscopy, Fourier transform infrared spectra, filled polymers, crystal growth from solution, polymer structureOther keywords: potential antibacterial material, antibiofilm potential, magnetite nanoparticles, solvothermal‐assisted green synthesis, hybrid Chi‐Fe₃ O₄ nanocomposites, staphylococcus aureus, staphylococcus marcescens, bacterial pathogens, ultraviolet–visible spectrum, spherical‐shaped particles, particle size, transmission electron microscopy, FESEM, field emission scanning electron microscopy, X‐ray diffraction, spinel structure, polycrystalline structure, energy dispersive X‐ray microanalysis, Fourier transform infrared spectroscopic analysis, deformation, bacterial cell walls, Fe₃ O₄      

Functionalisation of Fe3 O4 nanoparticles by 2‐((pyrazol‐4‐yl) methylene) hydrazinecarbothioamide enhances the apoptosis of human breast cancer MCF‐7 cells

Cancer is a major cause of death. Thus, the incidence and mortality rate of cancer is globally important. Regarding vast problems caused by chemotherapy drugs, efforts have progressed to find new anti‐cancer drugs. Pyrazole derivatives are known as components with anti‐cancer properties. In here, Fe₃ O₄ nanoparticles were first functionalized with (3‐chloropropyl) trimethoxysilane, then 2‐((pyrazol‐4‐yl) methylene) hydrazinecarbothioamide (P) was anchored on the surface of magnetic nanoparticles (PL). The synthesized nano‐compounds were characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, Zeta potential, dynamic light scattering, and energy‐dispersive x‐ray spectrometry analyses. The cytotoxicity effect was evaluated using MTT assay, apoptosis test by Flow cytometry, cell cycle analysis, Caspase‐3 activity assay and Hoechst staining on MCF‐7 cell line. The high toxicity for tumor cells and low toxicity on normal cells (MCF10A) was considered as an important feature (selectivity index, 10.9). Based on results, the IC50 for P and PL compounds were 157.80 and 131.84 μM/ml respectively. Moreover, apoptosis inducing, nuclear fragmentation, Caspase 3 activity and induction of cell rest in sub‐G1 and S phases, were also observed. The inhibitory effect of PL was significantly higher than P, which could be due to the high penetrability of Fe₃ O₄ nanoparticles.Inspec keywords: magnetic particles, drugs, nanomedicine, biochemistry, cancer, light scattering, scanning electron microscopy, molecular biophysics, iron compounds, electrokinetic effects, nanofabrication, tumours, X‐ray diffraction, cellular biophysics, nanoparticles, biomedical materials, toxicology, nanomagnetics, Fourier transform infrared spectra, enzymes, X‐ray chemical analysisOther keywords: anticancer properties, Fe₃ O₄ magnetic nanoparticles, (3‐chloropropyl) trimethoxysilane, energy‐dispersive X‐ray spectrometry, cell cycle analysis, MCF‐7 cell line, tumour cells, human breast cancer MCF‐7 cells, mortality rate, pyrazole derivatives, 2‐((pyrazol‐4‐yl) methylene) hydrazinecarbothioamide, chemotherapy drugs, heterocyclic components, nanocompounds, X‐ray diffraction, scanning electron microscopy, Zeta potential, dynamic light scattering, cytotoxicity effect, MTT assay, apoptosis test, caspase‐3 activity assay, Hoechst staining, MCF10A nontumourigenic cells, cell rest induction, nuclear fragmentation, Fe₃ O₄      

HSA loaded with CoFe2 O4 /MNPs as a high‐efficiency carrier for epirubicin anticancer drug delivery

Drug delivery is one of the most important challenges in the domain of health. Non‐toxic and biocompatible carriers are provided by human serum albumin nano‐capsule (HSA/NC) for drug delivery applications. In this study, HSA, with high loadings of drug‐modified cobalt ferrite (CoFe₂ O₄) magnetic nanoparticle (CoFe₂ O₄ /MNPs) was fabricated for epirubicin anticancer drug delivery. In the initial step, CoFe₂ O₄ /MNPs was synthesised via co‐precipitation technique and characterised by X‐ray powder diffraction, vibrating sample magnetometry, energy dispersive X‐ray analysis, scanning electron microscopy and map analysis. Furthermore, CoFe₂ O₄ /MNPs and epirubicin were loaded into HSA/NC and utilised as a novel system against breast cancer cell line (MCF‐7). IC₅₀ for free epirubicin, unloaded CoFe₂ O₄ /MNPs/HSA/NC, CoFe₂ O₄ /MNPs and epirubicin‐loaded CoFe₂ O₄ /MNPs/HSA/NC were 7.7, 2400, 840 and 430 μg/ml, respectively. The results obtained revealed high cytotoxicity effect of epirubicin‐loaded CoFe₂ O₄ /MNPs on breast cancer cell line.Inspec keywords: drug delivery systems, biomedical materials, nanoparticles, cobalt compounds, ferrites, nanomedicine, proteins, molecular biophysics, drugs, magnetic particles, nanomagnetics, nanofabrication, precipitation (physical chemistry), X‐ray diffraction, X‐ray chemical analysis, scanning electron microscopy, cancer, cellular biophysics, toxicology, magnetic hysteresisOther keywords: HSA, high‐efficiency carrier, epirubicin anticancer drug delivery, human serum albumin nanocapsule, drug‐modified cobalt ferrite magnetic nanoparticle, coprecipitation technique, X‐ray powder diffraction, vibrating sample magnetometry, energy dispersive X‐ray analysis, scanning electron microscopy, map analysis, breast cancer cell line, cytotoxicity effect, CoFe₂ O₄      

Photocatalytic degradation of synthetic dyes using iron (III) oxide nanoparticles (Fe2 O3 ‐Nps) synthesised using Rhizophora mucronata Lam

Biosynthesis of nanoparticles through plant extracts is gaining attention due to the toxic free synthesis process. The environmental engineering applications of many metal oxide nanoparticles have been reported. In this study, iron oxide nanoparticles (Fe₂ O₃ ‐Nps) were synthesised using a simple biosynthetic method using a leaf extract of a mangrove plant Rhizophora mucronata through reduction of 0.01 M ferric chloride. Fe₂ O₃ ‐Np synthesis was revealed by a greenish colour formation with a surface plasmon band observed close to 368 nm. The stable Fe₂ O₃ ‐Np possessed excitation and emission wavelength of 368.0 and 370.5 nm, respectively. The Fourier‐transform infrared spectral analysis revealed the changes in functional groups during formation of Fe₂ O₃ ‐Np. Agglomerations of nanoparticles were observed during scanning electron microscopic analysis and energy‐dispersive X‐ray spectroscopic analysis confirmed the ferric oxide nature. The average particle size of Fe₂ O₃ ‐Np based on dynamic light scattering was 65 nm. Based on transmission electron microscopic analysis, particles were spherical in shape and the crystalline size was confirmed by selected area electron diffraction pattern analysis. The synthesised Fe₂ O₃ ‐Np exhibited a good photodegradation efficiency with a reduction of 83 and 95% of phenol red and crystal violet under irradiation of sunlight and florescent light, respectively. This report is a facile synthesis method for Fe₂ O₃ ‐Np with high photodegradation efficiency.Inspec keywords: photochemistry, dyes, nanofabrication, transmission electron microscopy, scanning electron microscopy, nanoparticles, iron compounds, X‐ray diffraction, catalysts, catalysis, particle size, X‐ray chemical analysis, electron diffraction, Fourier transform infrared spectra, surface plasmonsOther keywords: energy‐dispersive X‐ray spectroscopic analysis, ferric oxide nature, transmission electron microscopic analysis, selected area electron diffraction pattern analysis, iron oxide nanoparticles, plant extracts, toxic free synthesis process, metal oxide nanoparticles, metal nanoparticles, nanofiltration, nanobiocides, Rhizophora mucronata Lam, crystalline size, phenol red, crystal violet, sunlight irradiation, florescent light, scanning electron microscopic analysis, Fourier‐transform infrared spectral analysis, surface plasmon, ferric chloride, leaf extract, nanocatalysts, nanoadsorbents, photocatalytic degradation, synthetic dyes, mangrove plant, water remediation, wastewater pollutant, wavelength 370.5 nm, wavelength 368.0 nm, Fe₂ O₃      

Fluorescein isothiocyanate‐dyed mesoporous silica nanoparticles for tracking antioxidant delivery

This study investigated the cellular uptake of fluorescein isothiocyanate‐labelled mesoporous silica nanoparticles (FITC‐MSNs), amine‐functionalised FITC‐MSNs (AP‐FITC‐MSNs) and their gallic acid (GA)‐loaded counterparts. Mesoporous silica nanoparticles were labelled with fluorescein isothiocyanate, functionalised by 3‐aminopropyltriethoxysilane (APTES) (AP‐FITC‐MSNs) and then loaded by GA. All nanoparticles were characterised by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, and X‐ray diffraction. The cytotoxicity of different concentrations of dyed nanoparticles was investigated using (3‐(4,5‐trihydroxybenzoic acid, dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay and flow cytometry. TEM images showed that the average particle sizes of FITC‐MSNs and AP‐FITC‐MSNs were about 100 and 110 nm, respectively. These nanoparticles were internalised by Caco‐2 cells, accumulated and dispersed into the cytoplasm, nucleus, and subcellular organelles. Nanoparticles containing GA clearly decreased the viability of cells. FITC‐MSNs showed no toxicity on Caco‐2 cells at concentrations of ≤50 µg/ml. Functionalisation of FITC‐MSNs using APTES decreased toxicity effects on the cells. It was found that FITC‐MSNs can be applied at low concentrations as a marker in the cells. In addition, AP‐FITC‐MSNs showed better biocompatibility with Caco‐2 cells than FITC‐MSNs, because of their positive surface charges.Inspec keywords: mesoporous materials, porosity, nanoparticles, dyes, silicon compounds, nanocomposites, nanofabrication, nanomedicine, cellular biophysics, molecular biophysics, biochemistry, transmission electron microscopy, Fourier transform infrared spectra, X‐ray diffraction, toxicology, particle size, biomedical materials, surface charging, cancerOther keywords: fluorescein isothiocyanate‐dyed mesoporous silica nanoparticles, antioxidant delivery tracking, cellular uptake, amine‐functionalised FITC‐MSNs, gallic acid‐loaded counterparts, 3‐aminopropyltriethoxysilane, transmission electron microscopy, TEM, Fourier transform infrared spectroscopy, X‐ray diffraction, cytotoxicity, dyed nanoparticles, (3‐(4,5‐trihydroxybenzoic acid‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay, flow cytometry, particle sizes, AP‐FITC‐MSNs, Caco‐2 cells, cytoplasm, subcellular organelles, cell viability, biocompatibility, positive surface charges, SiO₂      

Green synthesis of magnetically recoverable Fe3 O4 /HZSM‐5 and its Ag nanocomposite using Juglans regia L. leaf extract and their evaluation as catalysts for reduction of organic pollutants

In this work, an Fe₃ O₄ /HZSM‐5 nanocomposite was synthesised in the presence of Juglans regia L. leaf extract. Then, silver nanoparticles (Ag NPs) were immobilised on the surface of prepared magnetically recoverable HZSM‐5 using selected extract for reduction of Ag⁺ ions to Ag NPs and their stabilisation on the surface of the nanocomposite. The reduction of Ag⁺ ions occurs at room temperature within a few minutes. Characterisation of the prepared catalysts has been carried out using fourier transform infrared (FT‐IR), X‐ray diffraction, field‐emission scanning electron microscopy (FESEM), energy‐dispersive spectroscopy, Brunauer–Emmett–Teller method, and a vibrating sample magnetometer. According to the FESEM images of the nanocomposites, the average size of the Ag NPs on the Fe₃ O₄ /HZSM‐5 surface was >70 nm. The Ag/Fe₃ O₄ /HZSM‐5 nanocomposite was a highly active catalyst for the reduction of methyl orange and 4‐nitrophenol in aqueous medium. The utilisation of recycled catalyst for three times in the reduction process does not decrease its activity.Inspec keywords: silver, X‐ray chemical analysis, X‐ray diffraction, nanocomposites, reduction (chemical), nanofabrication, nanoparticles, transmission electron microscopy, catalysts, Fourier transform infrared spectra, iron compounds, field emission scanning electron microscopy, zeolites, magnetometry, particle sizeOther keywords: Ag‐Fe₃ O₄ , temperature 293 K to 298 K, green synthesis, catalyst material, 4‐nitrophenol reduction, methyl orange reduction, particle size, vibrating sample magnetometry, Brunauer–Emmett–Teller method, field‐emission scanning electron microscopy, X‐ray diffraction, FT‐IR spectroscopy, silver nanoparticles, Juglans regia L. leaf extract, organic pollutant reduction, magnetically recoverable nanocomposites, energy‐dispersive spectroscopy     

Superparamagnetic cobalt ferrite nanoparticles as T 2 contrast agent in MRI: in vitro study

Superparamagnetic cobalt ferrite nanoparticles (CoFe₂ O₄) possess favourite advantages for theranostic applications. Most of previous studies reported that CoFe₂ O₄ magnetic nanoparticles (MNPs) are suitable candidates for induction of hyperthermia and transfection agents for drug delivery. The present study synthesized and investigated the potential use of CoFe₂ O₄ as a contrast agent in magnetic resonance imaging (MRI) by using a conventional MRI system. The CoFe₂ O₄ were synthesized using co‐precipitation method and characterized by TEM, XRD, FTIR, EDX and VSM techniques. Relaxivities r ₁ and r ₂ of CoFe₂ O₄ were then calculated using a 1.5 Tesla clinical magnetic field. The cytotoxicity of CoFe₂ O₄ was evaluated by the MTT assay. Finally, the optimal concentrations of MNPs for MRI uses were calculated through the analysis of T ₂ weighted imaging cell phantoms. The superparamagnetic CoFe2O4 NPs with an average stable size of 10.45 nm were synthesized. Relaxivity r ₁, ₂ calculations resulted in suitable r ₂ and r ₂ / r ₁ with values of 58.6 and 51 that confirmed the size dependency on relaxivity values. The optimal concentration of MNPs for MR image acquisition was calculated as 0.154 mM. Conclusion: CoFe₂ O₄ synthesized in this study could be considered as a suitable T ₂ weighted contrast agent because of its high r ₂ /r ₁ value.Inspec keywords: nanoparticles, phantoms, transmission electron microscopy, superparamagnetism, ferrites, cellular biophysics, precipitation (physical chemistry), magnetisation, cobalt compounds, nanomagnetics, magnetic particles, nanofabrication, biomedical MRI, nanomedicine, X‐ray diffraction, Fourier transform infrared spectra, X‐ray chemical analysis, particle size, medical image processingOther keywords: superparamagnetic cobalt ferrite nanoparticles, T₂ contrast agent, MRI, in vitro study, magnetic resonance imaging, coprecipitation method, transmission electron microscopy, X‐ray diffraction, Fourier‐transform IR spectra, energy dispersive X‐ray analysis, vibrating sample magnetometer, clinical magnetic field, cytotoxicity, MTT assay, T₂ weighted imaging cell phantoms, T₂ weighted contrast agent, stable size, size dependency, relaxivity values, MR image acquisition, magnetic flux density 1.5 T, CoFe₂ O₄      

Synthesis,characterisation and potential biomedical applications of magnetic core–shell structures: carbon‐, dextran‐, SiO2 ‐ and ZnO‐coated Fe3 O4 nanoparticles

Due to the strong effect of nanoparticles'' size and surface properties on cellular uptake and bio‐distribution, the selection of coating material for magnetic core–shell nanoparticles (CSNPs) is very important. In this study, the effects of four different biocompatible coating materials on the physical properties of Fe₃ O₄ (magnetite) nanoparticles (NPs) for different biomedical applications are investigated and compared. In this regard, magnetite NPs are prepared by a simple co‐precipitation method. Then, CSNPs including Fe₃ O₄ as a core and carbon, dextran, ZnO (zincite) and SiO₂ (silica) as different shells are synthesised using simple one‐ or two‐step methods. A comprehensive study is carried out on the prepared samples using X‐ray diffraction, vibrating sample magnetometry, transmission electron microscopy and Fourier transform infrared spectroscopy analyses. According to the authors'' findings, it is suggested that carbon‐ and dextran‐coated magnetite NPs with high M _s have great potential in the application of magnetic resonance imaging contrast agents. Moreover, silica‐coated magnetite NPs with high coercivity are potentially suitable candidates for hyperthermia and ZnO‐coated Fe₃ O₄ is potentially suitable for photothermal therapy.Inspec keywords: iron compounds, carbon, silicon compounds, zinc compounds, nanomedicine, biomedical materials, nanofabrication, nanoparticles, magnetic particles, coatings, X‐ray diffraction, magnetometry, transmission electron microscopy, Fourier transform spectra, infrared spectra, biomedical MRI, hyperthermia, radiation therapyOther keywords: biomedical applications, magnetic core‐shell nanoparticles, CSNP, cellular uptake, biodistribution, coating material, biocompatible coating materials, co‐precipitation, dextran, zincite, silica, X‐ray diffraction, vibrating sample magnetometry, transmission electron microscopy, Fourier transform infrared spectroscopy, magnetic resonance imaging contrast agents, hyperthermia, photothermal therapy, SiO₂ ‐Fe₃ O₄ , ZnO‐Fe₃ O₄      

Biosynthesis of γ ‐Fe2 O3 @CuO core–shell nanoclusters using aqueous extract of Sesbania grandiflora Linn fresh leaves,its characterisation,and antimicrobial activity studies against Staphylococcus aureus strains

The present study reports an eco‐friendly and rapid method for the synthesis of core–shell nanoclusters using the modified reverse micelle method. It is a green synthetic method which uses Sesbania grandiflora Linn extract which acts as a reducing and capping agent. It is observed that this method is very fast and convenient and the nanoclusters are formed with 5–10 min of the reaction time without using harsh conditions. The core–shell nanoclusters so prepared were characterised using UV–Vis spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy. Further, their effective antibacterial activity towards the gram‐positive bacteria Staphylococcus aureus was found to be due to their smaller particle size.Inspec keywords: iron compounds, copper compounds, nanoparticles, particle size, nanofabrication, nanomedicine, biomedical materials, core‐shell nanostructures, antibacterial activity, ultraviolet spectra, visible spectra, microorganisms, reduction (chemical), scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectraOther keywords: biosynthesis, γ‐Fe₂ O₃ ‐CuO core‐shell nanoclusters, aqueous extract, Sesbania grandiflora Linn fresh leaves, antimicrobial activity, Staphylococcus aureus strains, eco‐friendly method, modified reverse micelle method, green synthetic method, reducing agent, capping agent, UV‐visible spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, antibacterial activity, gram‐positive bacteria Staphylococcus aureus, particle size, time 5 min to 10 min, Fe₂ O₃ ‐CuO     

Antifungal and antiovarian cancer properties of α Fe2 O3 and α Fe2 O3 /ZnO nanostructures synthesised by Spirulina platensis

Candida albicans (C. albicans) infection shows a growing burden on human health, and it has become challenging to search for treatment. Therefore, this work focused on the antifungal activity, and cytotoxic effect of biosynthesised nanostructures on human ovarian tetracarcinoma cells PA1 and their corresponding mechanism of cell death. Herein, the authors fabricated advanced biosynthesis of uncoated α‐Fe₂ O₃ and coated α‐Fe₂ O₃ nanostructures by using the carbohydrate of Spirulina platensis. The physicochemical features of nanostructures were characterised by UV–visible, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy, and X‐ray diffraction. The antifungal activity of these nanostructures against C. albicans was studied by the broth dilution method, and examined by 2′, 7′‐dichlorofluorescein diacetate staining. However, their cytotoxic effects against PA1 cell lines were evaluated by MTT and comet assays. Results indicated characteristic rod‐shaped nanostructures, and increasing the average size of α‐Fe₂ O₃ @ZnO nanocomposite (105.2 nm × 29.1 nm) to five times as compared to α‐Fe₂ O₃ nanoparticles (20.73nm × 5.25 nm). The surface coating of α‐Fe₂ O₃ by ZnO has increased its antifungal efficiency against C. albicans. Moreover, the MTT results revealed that α‐Fe₂ O₃ @ZnO nanocomposite reduces PA1 cell proliferation due to DNA fragmentation (IC₅₀ 18.5 μg/ml). Continual advances of green nanotechnology and promising findings of this study are in favour of using the construction of rod‐shaped nanostructures for therapeutic applications.Inspec keywords: nanocomposites, toxicology, nanofabrication, cellular biophysics, X‐ray diffraction, iron compounds, biochemistry, cancer, antibacterial activity, transmission electron microscopy, biomedical materials, wide band gap semiconductors, DNA, II‐VI semiconductors, visible spectra, molecular biophysics, ultraviolet spectra, nanomedicine, zinc compounds, nanoparticles, microorganisms, Fourier transform infrared spectraOther keywords: Spirulina platensis, antifungal activity, α‐Fe₂ O₃ nanoparticles, antiovarian cancer properties, Candida albicans infection, cytotoxic effect, biosynthesised nanostructures, human ovarian tetracarcinoma cell PA1, cell death, uncoated α‐Fe₂ O₃ , coated α‐Fe₂ O₃ nanostructures, α‐Fe₂ O₃ ‐ZnO nanocomposite, carbohydrate, physicochemical features, UV‐visible spectroscopy, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, broth dilution method, 2′, 7′‐dichlorofluorescein diacetate staining, PA1 cell lines, comet assays, MTT assays, rod‐shaped nanostructures, surface coating, PA1 cell proliferation, DNA fragmentation, green nanotechnology, Fe₂ O₃ ‐ZnO, Fe₂ O₃      

Recyclable adsorbents based on Fe3 O4 nanoparticles on lanthanum‐modified montmorillonite for the efficient phosphate removal

Montmorillonite (MMT) clay modified with lanthanum (La) ions and Fe₃ O₄ nanoparticles was proposed for the effective removal of phosphate ions from aqueous solution. Characterisation of the adsorbent using FTIR, SEM, XRD, XPS, XRF, BET and VSM techniques were carried out. The effects of initial phosphate concentration, contact time, dosage and pH on the phosphorus adsorption were investigated. La‐MMT/Fe₃ O₄ exhibited an excellent adsorption capacity of up to 14.35 mg/g, with 97.8% removal within 60 min. Langmuir isotherm model fits well with the equilibrium isotherm data, with a maximum adsorption capacity of 15.53 mg/g at room temperature. The kinetic study was well fitted with pseudo‐second‐order kinetics, and the adsorption rate was mainly controlled by liquid‐film diffusion. The manufactured adsorbent was effectively regenerated using 0.1 M NaOH solutions, with 90.18% adsorption efficiency remaining after six adsorption/desorption cycles. These results demonstrate that La‐MMT/Fe₃ O₄ provides an example of regenerable high‐performance adsorbents for removal of PO₄ ³⁻ from wastewater.Inspec keywords: wastewater treatment, desorption, phosphorus, pH, recycling, adsorption, X‐ray diffraction, iron compounds, nanoparticles, X‐ray photoelectron spectra, clay, scanning electron microscopy, reaction kinetics theory, X‐ray fluorescence analysis, chemical engineering, chemical equilibrium, Fourier transform infrared spectra, sodium compounds, lanthanum, liquid films, diffusionOther keywords: maximum adsorption capacity, high‐performance adsorbents, recyclable adsorbents, lanthanum‐modified montmorillonite, montmorillonite clay, Langmuir isotherm model, phosphate removal, aqueous solution, FTIR spectroscopy, SEM, XRD, XPS, XRF, BET, VSM techniques, pH value, equilibrium isotherm data, pseudo second‐order kinetics, liquid‐film diffusion, adsorbent regeneration, adsorption‐desorption cycles, wastewater treatment, temperature 293.0 K to 298.0 K, time 60.0 min, NaOH, La, P     

Antioxidant and antibacterial activity evaluation of 3‐hydroxybenzaldehyde: the product of thymol oxidation by a new magnetic nanocatalyst

In this study maghemite nanoparticles were synthesised, they were first coated by sodium alginate and then by chitosan. Then acetanilide was introduced to maghemite nanoparticles that were coated by alginate and chitosan. Finally a silver complex was made with acetanilide and the magnetic nanocatalyst was synthesised. This nanocatalyst was used for the oxidation of thymol, then antioxidant and antibacterial properties of the oxidation product were assessed. Characterisation of this nanocatalyst was performed by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffractometer, scanning electron microscope (SEM) and value stream mapping. Creation of the product was confirmed by FT‐IR and gas chromatography‐mass spectroscopy. According to SEM, the size of the nanocatalyst was in the range of 46–70 nm. 3‐hydroxybenzaldehyde was obtained from the oxidation of thymol. It had antioxidant property as evident from Di (phenyl) – (2, 4, 6‐trinitrophenyl) iminoazanium and the Folin–Ciocalteu method. Diffusion and dilution methods were used for the evaluation of the antibacterial activity. It was obvious from MIC that gram negative strains were more resistant than gram positive ones, and from minimum bactericidal concentration, it was obvious that Escherichia coli was the most resistant gram negative strain, and Bacillus subtilis was the most resistant gram positive strain.Inspec keywords: nanoparticles, iron compounds, magnetic particles, nanomagnetics, antibacterial activity, oxidation, organic compounds, Fourier transform infrared spectra, X‐ray diffraction, scanning electron microscopy, chromatography, diffusion, mass spectroscopic chemical analysis, microorganisms, catalysts, nanofabricationOther keywords: maghemite nanoparticles, sodium alginate, chitosan, acetanilide, magnetic nanocatalyst, thymol oxidation, antioxidant properties, antibacterial activity, Fourier transform infrared spectroscopy, X‐ray diffractometer, scanning electron microscope, value stream mapping, FTIR, gas chromatography‐mass spectroscopy, 3‐hydroxybenzaldehyde, Folin–Ciocalteu method, diffusion, dilution, gram negative strains, Escherichia coli, Bacillus subtilis, gram positive strain, Fe₂ O₃      

Rapid synthesis of Bi 2 O 3 nano‐needles via ‘green route’ and evaluation of its anti‐fungal activity

Here, the authors report a rapid, simple, and eco‐friendly process for synthesis of Bi₂ O₃ nano‐needles. Dioscorea alata tuber extract was used as both reducing and capping agent for the first time. These nanoparticles were characterised by X‐ray diffraction, field emission scanning electron microscope, and Fourier transform infrared (FTIR) spectrometry, the nano‐structured Bi₂ O₃ needles have an average diameter of 158 nm with the lengths in the range of 1–3 μm. CLSI M27‐A2 standard was followed for evaluation of anti‐fungal activity. Bi₂ O₃ nano‐needles show remarkable activity against Candida albicans. It exhibits four time greater activity than bulk Bi₂ O₃ powder and two time greater activity than itraconazole, which makes it a potent anti‐fungal drug.Inspec keywords: bismuth compounds, nanoparticles, X‐ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectra, drugs, nanomedicine, biomedical materials, nanofabricationOther keywords: nanoneedles, antifungal activity, nanoparticles, X‐ray diffraction, field emission scanning electron microscope, Fourier transform infrared spectrometry, CLSI M27‐A2 standard, Candida albicans, itraconazole, antifungal drug, Bi₂ O₃      

Development and characterisation of novel Ce‐doped hydroxyapatite–Fe3 O4 nanocomposites and their in vitro biological evaluations for biomedical applications

Hydroxyapatite (HAP: Ca₁₀ (PO₄)₆ (OH)₂) is extensively used in biomedical field because of its biocompatibility, osteoconductivity and non‐toxicity properties. However, HAP exhibits poor mechanical strength and bacterial restriction behavior. To overcome these drawbacks, various metal ions such as Ag⁺, Zn²⁺, Cu²⁺, Ti⁴⁺ and Ce^4+/3+ are incorporated in HAP matrix to increase the mechanical and biological properties. Among these, Cerium (Ce) is selected as antibacterial agent due to its high thermal stability and its applications in dental fillings, bone healing and catheters. Fe₃ O₄ nanoparticles were used in hyperthermia treatment, magnetic fluid recordings and catalysis. In this present study, we have synthesized nanocomposites consisting of 1.25% Ce doped HAP with various concentrations of Fe₃ O₄ NPs as 90:10 (C‐1), 70:30 (C‐2) and 50:50 wt% (C‐3) using ball milling technique. The obtained Ce@HAP‐Fe₃ O₄ nanocomposites were characterized by ATR‐FTIR, XRD, VSM, SEM‐EDAX and TEM analysis. Further, the fabricated Ce@HAP‐Fe₃ O₄ nanocomposites were tested for its antibacterial activity towards Staphylococcus aureus (S. aureus) and Escherichia coli (E.coli), where C‐3 composites exhibit the excellent pathogen inhibition towards E.coli. In addition, the cytotoxicity evaluation on C‐3 nanocomposites by in vitro biocompatibility study using MG‐63 cells shows the prominent viable cell enhancement up to 400µg/mL concentrations.Inspec keywords: nanocomposites, iron compounds, calcium compounds, cerium, mechanical strength, antibacterial activity, biomedical materials, dentistry, bone, nanoparticles, nanofabrication, ball milling, Fourier transform infrared spectra, attenuated total reflection, X‐ray diffraction, magnetometry, scanning electron microscopy, transmission electron microscopy, microorganisms, cellular biophysics, nanomedicineOther keywords: Ce‐doped HAP–Fe3O4 nanocomposite, hydroxyapatite, in vitro biological evaluation, mechanical strength, bacterial restriction behaviour, metal ion, silver ion, zinc ion, copper ion, titanium ion, cerium ion, HAP matrix, antibacterial agent, thermal stability, dental filling, bone healing, catheter, Fe3O4 nanoparticle, hyperthermia treatment, magnetic fluid recording, catalysis, ball milling technique, Fourier transform infrared spectroscopy, attenuated total reflectance spectroscopy, X‐ray diffraction, vibrating sample magnetometry, scanning electron microscopy, SEM‐energy dispersive spectroscopy, transmission electron microscopy, TEM analysis, antibacterial activity, Staphylococcus aureus, Escherichia coli, pathogen inhibition, in vitro biocompatibility, MG‐63 osteoblast cell, cell enhancement, Ca₅ (PO₄)₃ (OH):Ce, Fe₃ O₄      

Methanobactin‐mediated synthesis of bimetallic Au–Pd/Al2 O3 toward an efficient catalyst for glucose oxidation

A green bioreductive approach with methanobactin was adopted to fabricate bimetallic Au–Pd/Al₂ O₃ catalysts for solvent‐free oxidation of glucose to gluconic acid with H₂ O₂ at atmospheric pressure. The catalyst was characterised by diffuse reflectance UV–vis spectroscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy, and X‐ray diffraction techniques to understand synergistic interactions between Au and Pd. Effects of Au to Pd molar ratio on the catalytic activity of Au–Pd/Al₂ O₃ were investigated. The Au–Pd/Al₂ O₃ catalyst with Au/Pd molar ratio of 0.8:0.2 exhibited excellent catalytic performance. With the catalyst, the oxidation activities of glucose to gluconic acid 2856 mmol min⁻¹ g⁻¹ and selectivity 99.6% were attained at 323 K with H₂ O₂. The results indicated the activity and selectivity was affected by the ratio of Au/Pd on the Al₂ O₃. The formation of Au_0.8 Pd_0.2 /Al₂ O₃ was favourable for the catalytic reaction.Inspec keywords: sugar, oxidation, biochemistry, gold, lead, aluminium compounds, catalysts, X‐ray diffraction, ultraviolet spectra, X‐ray photoelectron spectra, transmission electron microscopy, visible spectra, catalysis, biological techniquesOther keywords: bimetallic Au‐Pd‐Al₂ O₃ methanobactin‐mediated synthesis, glucose oxidation, green bioreductive approach, bimetallic Au‐Pd‐Al₂ O₃ catalysts, glucose solvent‐free oxidation, gluconic acid, Au‐to‐Pd molar ratio, catalytic reaction, X‐ray diffraction, X‐ray photoelectron spectroscopy, transmission electron microscopy, diffuse reflectance UV‐vis spectroscopy, temperature 323 K, Au‐Pd‐Al₂ O₃      

Novel synthesis of ultra‐fine Sb2 O3 nanocubes using plant extract

In this study, the synthesis of ultra‐fine grade antimony trioxide (Sb₂ O₃) using plant extract for the first time is reported. Antimony chloride was used as a starting material and Dioscorea alata tuber extract was used as a reducing and capping agent. The synthesised nanoparticles were characterised by X‐ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), dynamic light scattering (DLS), and Fourier transform infrared spectroscopy. XRD analysis indicates the formation of pure Sb₂ O₃ nanoparticles. The result from FE‐SEM and DLS showed that the particles have a cube‐like morphology and have an average size of 346.4 nm which falls within the range of ultra‐fine grade Sb₂ O₃.Inspec keywords: field emission electron microscopy, scanning electron microscopy, X‐ray diffraction, particle size, nanofabrication, light scattering, transmission electron microscopy, ultraviolet spectra, nanoparticles, antimony compounds, Fourier transform infrared spectraOther keywords: field emission scanning electron microscopy, FE‐SEM, dynamic light scattering, DLS, XRD analysis, antimony chloride, starting material, reducing agent, ultrafine grade antimony trioxide, plant extract, dioscorea alata tuber extract, capping agent, X‐ray diffraction, pure antimony trioxide nanoparticles, cube‐like morphology, Sb₂ O₃      

Synthesis of ZnO/Fe3 O4 /rGO nanocomposites and evaluation of antibacterial activities towards E. coli and S. aureus

Antibacterial activity of nanoparticles (NPs) and nanocomposites (NCs) has received wide spread attention in biomedical applications. In this direction, the authors prepared zinc oxide (ZnO), iron oxide (Fe₃ O₄), and their composite including reduced graphene oxide (rGO) by hydrothermal method. The structural and microstructural properties of the synthesised NPs and NCs were investigated by XRD, FT‐IR, UV‐Vis, TGA, and TEM analysis. PEG‐coated ZnO and Fe₃ O₄ form in hexagonal wurtzite and inverse spinel structures, respectively. ZnO forms in rod‐shaped (aspect ratio of ∼3) morphology, whereas well‐dispersed spherical‐shaped morphology of ∼10 nm is observed in Fe₃ O₄ NPs. The ZnO/Fe₃ O₄ composite possesses a homogeneous distribution of above two phases and shows a very good colloidal stability in aqueous solvent. These synthesised particles exhibited varying antibacterial activity against gram‐positive strain Staphylococcus aureus (S. aureus) and gram‐negative strain Escherichia coli (E. coli). The nanocomposite exhibits a better cidal effect on E. coli when compared to S. aureus when treated with 1 mg/ml concentration. Further, the addition of rGO has intensified the anti‐bacterial effect to a much higher extent due to synergistic influence of individual components.Inspec keywords: colloids, visible spectra, II‐VI semiconductors, thermal analysis, nanofabrication, X‐ray diffraction, nanoparticles, biomedical materials, wide band gap semiconductors, transmission electron microscopy, ultraviolet spectra, antibacterial activity, nanocomposites, zinc compounds, nanobiotechnology, Fourier transform infrared spectra, graphene compounds, iron compounds, crystal growth from solution, crystal morphologyOther keywords: antibacterial activity, E. coli, biomedical applications, iron oxide, hydrothermal method, structural properties, microstructural properties, PEG‐coated ZnO, hexagonal wurtzite, inverse spinel structures, gram‐positive strain Staphylococcus aureus, S. aureus, gram‐negative strain Escherichia coli, nanocomposites, nanoparticles, XRD, FTIR spectra, UV‐vis spectra, TGA, TEM, rod‐shaped morphology, spherical‐shaped morphology, colloidal stability, cidal effect, ZnO‐Fe₃ O₄ ‐CO     

Folate encapsulation in PEG‐diamine grafted mesoporous Fe3 O4 nanoparticles for hyperthermia and in vitro assessment

Effective and targeted delivery of the antitumour drugs towards the specific cancer spot is the major motive of drug delivery. In this direction, suitably functionalised magnetic iron oxide nanoparticles (NPs) have been utilised as a theranostic agent for imaging, hyperthermia and drug delivery applications. Herein, the authors reported the preparation of multifunctional polyethyleneglycol‐diamine functionalised mesoporous superparamagnetic iron oxide NPs (SPION) prepared by a facile solvothermal method for biomedical applications. To endow targeting ability towards tumour site, folic acid (FA) is attached to the amine groups which are present on the NPs surface by 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide hydrochloride/N‐hydroxysuccinimide chemistry. FA attached SPION shows good colloidal stability and possesses high drug‐loading efficiency of ∼ 96% owing to its mesoporous nature and the electrostatic attachment of daunosamine (NH₃ ⁺) group of doxorubicin (DOX) towards the negative surface charge of carboxyl and hydroxyl group. The NPs possess superior magnetic properties in result endowed with high hyperthermic ability under alternating magnetic field reaching the hyperthermic temperature of 43°C within 223 s at NP''s concentration of 1 mg/ml. The functionalised NPs possess non‐appreciable toxicity in breast cancer cells (MCF‐7) which is triggered under DOX‐loaded SPION.Inspec keywords: nanoparticles, nanocomposites, mesoporous materials, colloids, biochemistry, nanomagnetics, molecular biophysics, tumours, superparamagnetism, drugs, toxicology, biomedical materials, nanofabrication, hyperthermia, cancer, magnetic particles, cellular biophysics, nanomedicine, iron compounds, drug delivery systems, filled polymers, biological organs, liquid phase depositionOther keywords: NP surface, colloidal stability, drug‐loading efficiency, hydroxyl group, magnetic properties, high hyperthermic ability, magnetic field, DOX‐loaded SPION, folate encapsulation, targeted delivery, antitumour drugs, specific cancer spot, magnetic iron oxide nanoparticles, theranostic agent, drug delivery applications, multifunctional polyethyleneglycol‐diamine, facile solvothermal method, biomedical applications, tumour site, amine groups, mesoporous superparamagnetic nanoparticles, PEG‐diamine grafted mesoporous nanoparticles, 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide hydrochloride‐N‐hydroxysuccinimide chemistry, daunosamine group, carboxyl group, breast cancer cells, temperature 43.0 degC, Fe₃ O₄