Concentration Of Fe3O4 Nanoparticles Research Articles

Synthesis, Characterization and Filtration Properties of Ecofriendly Fe3O4 Nanoparticles Derived from Olive Leaves Extract.

Recently, value-added nanomaterials including nanoparticles or nanofluids have been significantly used in designing drilling fluids with tunable rheological properties to meet specific downhole and environmental requirements. In this work, we report novel water-based drilling fluids (WBDF) containing eco-friendly Fe3O4 nanoparticles (Fe3O4-NPs) prepared by using olive leaves extract (OLE) as a reducing and capping agent. A series of economical and excellent performance of WBDF was obtained by introducing low, medium, and high concentrations of Fe3O4-NPs into the conventional WBDF. The synthesis of Fe3O4-NPs was accomplished through the thermal decomposition of iron precursors in an organic medium. NPs were added to the based fluid at concentrations of 0.01, 0.1, and 0.5 wt%. Emission scanning microscopy (FESEM), field- and Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Energy-dispersive X-ray analysis (EDX) were used for Fe3O4-NPs analysis. Compared to the conventional WBDF, the addition of Fe3O4-NPs as an additive in the based fluids has been investigated to help increasing viscosity and yield point, which is advantageous for hole cleaning, as well as decreasing fluid loss and mud cake thickness.

Nanoparticle-associated single step hydrogen fermentation for the conversion of starch potato waste biomass by thermophilic Parageobacillus thermoglucosidasius

In the present study, starch-based potato peel waste biomass (PWB) was utilized as a potential substrate for hydrogen production via dark fermentation by the thermophillic amylase producing strain Parageobacillus thermoglucosidasius KCTC 33548. Supplementation of Fe3O4 nanoparticles (300 mg/L) led to a 4.15-fold increase in hydrogen production as compared to the control. The addition of optimized concentrations of both Fe3O4 nanoparticles (300 mg/L) and L-cysteine (250 mg/L) during hydrogen fermentation using pure starch and PWB generated maximum cumulative hydrogen yields of 167 and 71.9 mL with maximum production rates of 2.81 and 1.26 mL/h, respectively. Further, the correlation between Fe3O4 and the expression of hydrogenase isoforms and the related hydrogenase activity was explored. The possible mechanisms of the action of Fe3O4 on enhanced hydrogenase activity and hydrogen production was elucidated. To our knowledge, there are no such studies reported on enhanced hydrogen production from PWB in a single step.

Effect of Fe3O4 nanoparticles on the performance of anaerobic digestion through electrochemical analysis

ABSTRACT In view of the high cost and complex operation of the traditional chemical method for the determination of the anaerobic digestion (AD) process, this study investigated the feasibility of using electrochemistry analysis to determine the effect of Fe3O4 nanoparticles (NPs) on the AD process. The quantity of electric charge of Fe3O4 NPs modified graphite electrode in sodium acetate electrolyte was higher than that of graphite electrode. The addition of Fe3O4 NPs was beneficial to improve the electrochemical activity of the electrode. On this basis, enzymes and microorganisms were extracted from anaerobic reactors containing different concentrations of Fe3O4 NPs to make electrodes respectively to further investigate the effects of Fe3O4 NPs on enzyme and microbial activities in AD. The electrochemical analysis results of the enzyme electrodes and microbial electrodes showed that the quantity of electric charge produced by the group of 200 mg/L Fe3O4 NPs was the highest. The cumulative biogas production of 200 mg/L Fe3O4 NPs was 809 mL/g VS, and better than other groups. These results showed that 200 mg/L Fe3O4 NPs was the best dosage, and the electrochemical analysis has higher sensitivity in the AD detection.

Metal based nanoparticles trigger the differential expression of key regulatory genes which regulate iron and zinc homeostasis mechanism in finger millet

Since green revolution, the food systems in most of the countries have dramatically changed but undernourishment still remains an inflammable problem. This alarming condition is even increasing due to the marginal supply of nutri-enriched food to eat. Under such chronically undernourished condition, dietary deficiencies of iron and zinc lead to compromised planetary health and economic losses. Given the micronutrient deficiency, there is an urgent call to devise or innovative a strategy for providing the requisite amount of iron and zinc in their daily intake to counter this issue. Thus being a high iron and zinc accumulating crop, finger millet can be efficiently used as an intricate model system to explore the prospects of genetic and molecular mechanisms which are responsible for nutrient enrichment in grains. We report here a promising role of nanotechnology in terms of their iron and zinc biofortification potentials in the finger millet. Comparative in vitro evaluation using lower concentration of Fe3O4 (100 ppm) and ZnO (5 ppm) nanoparticles (NPs) display a significant promotory effect on both mineral assimilation and growth parameters whereas higher concentrations of NPs, FeSO4.7H2O and ZnSO4.7H2O bulk salts marked inhibitory effects. The molecular modelling and docking interaction analysis infers that these nano-minerals may bind to significantly influence the modulation of regulatory genes. The result was further validated using real time PCR profiling. The differential expression profiling resulted in higher transcriptional modulation of iron and zinc transporters particularly EcFER1, EcIRT2, EcYSL2, EcZIP1 and EcZTP29 in nano-primed genotypes compared to controls. Thus in conclusion, being a nutrient by default and stress-resilient crop, nanoparticle formulations in finger millet triggers the epigenetic regulation of potential key regulatory genes involved in iron and zinc homeostasis. The study also indicates innovative role of nano-seed priming for biofortification which triggers differential modulation of iron and zinc acquisition and enrichment in grains despite nutrient limiting conditions.

Improvement of flux pinning properties in Fe3O4 nanoparticle-doped Bi1.6Pb0.4Sr2Ca2Cu3O10+δ superconductors

The flux pinning properties of polycrystalline (Bi1.6Pb0.4Sr2Ca2Cu3O10+δ)1−x(Fe3O4)x, with x = 0.00, 0.01, 0.02, 0.03, 0.04, and 0.05 superconductors were investigated. The collective pinning theory was successfully used to describe the magnetization critical current density (Jc) of all samples. The value of Jc was enhanced by the proper doping contents of Fe3O4 nanoparticles. Possible origins for these achievements were attributed to the increases in both flux pinning force and activation energy. The appearance of the additional point-like pinning centers was confirmed via Dew–Hughes model fitting analysis.

Fabrication and assessment of an electrochromic and radar-absorbent dual device based on the new smart polythiophene-based/RGO/Fe3O4 ternary nanocomposite

Both polymeric electrochromic and radar absorption materials have been considered as science hotspots over the past few decades. However, integrating both properties (electrochromic and radar absorption) in a single device has not been addressed to fabricate a multifunctional device so far. Thus, here, we endeavor to shed light on this uncharted area by presenting a new smart ternary nanocomposite (polythiophene-based/RGO-Fe3O4) which can provide both electrochromic and microwave absorbent features simultaneously. In this regard, we synthesized the binary Fe3O4-RGO nanocomposites with different contents of Fe3O4 nanoparticles. Then, this binary nanocomposite is utilized in combination with a polythiophene-based conductive polymer as a tricolor (RGB) organic electrochromic material to synthesize the smart ternary nanocomposite through both in-situ polymerization and physical mixing methods. The ternary nanocomposites containing different weight fractions of Fe3O4-RGO nanoparticles were used to assemble the rigid and flexible ECD devices using flat and fiber substrates such as glass-indium tin oxide (glass-ITO), polyethylene terephthalate-indium tin oxide (PET-ITO) and stainless steel wire (SSW). By applying a voltage of −2.1 to 2.1 v, a reversible color-switching ability was observed between green color (oxidized state), and red color (reduced state) for all ECDs. The average switching time and color memory for the SSW cell were determined to be about 3 s and 155 min, and for both glass-ITO and PET-ITO cells to be 2 s and 210 min, respectively. Additionally, the microwave absorption properties of the prepared ternary nanocomposites were characterized by measuring the electromagnetic parameters such as permittivity, permeability, and reflection loss. A ternary nanocomposite with 3 mm thickness filled with 50 wt% Fe3O4-RGO exhibited a maximum reflection loss as high as −30.2 dB (92% absorption) at 12.3 GHz (in the range of x-bond) with 1.1 GHz bandwidth.

Enhancement of magnetic film with light penetration by immobilization of Fe3O4 nanoparticles in a spherical bamboo nanocellulose network

The magnetic properties of the magnetic transparent composite films largely depend on the content of Fe3O4 employed. However, higher addition of Fe3O4 into the matrix will lead to Fe3O4 nanoparticles agglomeration resulting in the reduction in the transparency of the composite films. The contradiction between Fe3O4 nanoparticle content and transparency limits the application of transparent magnetic films. In this work, the spherical bamboo nanocellulose (SBN) with an average size of 61 nm was prepared from bamboo powder by NaOH/Urea/Thiourea aqueous system, which was an effective, inexpensive and less toxic strategy. The basic structure of SBN was investigated. The SBN exhibited the cellulose II type crystal structure. The molecular chain length of SBN were lower than before dissolution. The magnetic SBN/Fe3O4 composite films with light penetration were prepared. The results revealed that the dispersion of Fe3O4 nanoparticles in the SBN/Fe3O4 composite films was much better than that in nanofibrillated cellulose (NFC)/Fe3O4 composite films because of the abundant hydrogen bonds between Fe3O4 nanoparticles and SBN. The transparent results indicated the highest transmittance of the films was 94% in the wavelength range of visible light, which was almost 23.7% higher than that of NFC/Fe3O4 composite films with the same amount of Fe3O4 addition (15 wt%). The findings in this study also revealed that the SBN in the SBN/Fe3O4 composite films was distributed in layers. The saturation magnetization of the SBN/Fe3O4 composite films was 10.65 emu g−1 with 15 wt% Fe3O4 incorporated, which guaranteed the excellent magnetic properties.

Characterization of Magnetite/Iodized Oil Magnetic Fluid for Embolization and Hyperthermia Application

Fe3O4 nanoparticles/iodized oil magnetic fluids (FIOMFs) have showed potential in targeted hyperthermia for liver tumors; in this paper, FIOMFs were simply and conveniently prepared by dispersing the synthesized hydrophobic Fe3O4 nanoparticles (FNPs) in iodized oil; the stability, magnetothermal effects, and the biotoxicity of FIOMFs were evaluated. The results showed that the stability of FIOMFs was mainly influenced by the morphology and the size of FNPs. FNPs prepared with FeCl3·6H2O, oleylamine (OAm), ethylene glycol (EG), and stearic acid exhibited the best suspension stability, which could suspend in iodized oil stably for a long time. Depending on the FNP content and the parameters of the alternating magnetic field (AMF), the temperature of FIOMF in AMF can reach up to more than 70 °C within 60 s, exhibited excellent magnetothermal effects. The in vitro cytotoxicity tests indicated the cytotoxicity of FNPs is mainly influenced by its concentration in cells.

Improved biomethanation of horse manure through acid-thermal pretreatment and supplementation of iron nanoparticles under mesophilic and thermophilic conditions

This study aimed to investigate the impact of dilute acid-thermal pretreatment of horse manure (HM) on the characteristic changes followed by biomethanation of untreated (control) and pretreated HM using iron oxide (Fe3O4) nanoparticles (NPs) as additives at concentrations of 20 mg/L, 40 mg/L and 60 mg/L at mesophilic (35 ± 2 °C) and thermophilic (55 ± 2 °C) temperature conditions. The acid-thermal pretreatment enabled the depolymerisation of the lignocellulosic crystalline structure of HM resulting in the reduction of cellulose and hemicellulose by 93 % and 96 % respectively. Addition of deficient or surplus concentration of NPs or micronutrients may adversely influence the activity of microbes because the release of key enzymes is ion dependant. Addition of appropriate concentration of Fe3O4 NPs facilitates the release of Fe2+ and Fe3+ ions that contribute to the release of key enzymes, but the addition of surplus concentration results in the release of reactive and toxic-free radicals or intermediates that decline the activity of the microorganisms. Results disclosed that the maximum methane yield of 0.16 L/g CODreduced and 0.175 L/g CODreduced was achieved under mesophilic and thermophilic conditions from pretreated HM with an addition of 40 mg/L of Fe3O4 NPs with a COD reduction of 68 % and 56 %, respectively, whereas it was 0.14 L/g CODreduced and 0.15 L/g CODreduced with an addition of 60 mg/L of Fe3O4 NPs with corresponding COD reduction of 58 % and 62.5 %, respectively, from untreated HM. Based on the findings achieved in the study, it is proven that the HM is a potential feedstock for biogas/methane generation. Incorporating the advanced techniques such as acid-thermal pretreatment and addition of supplements in the form of NPs further enhances the biomethanation process making it more lucrative and feasible for implementation at full scale.

Photothermal Effect of Superparamagnetic Fe3O4 Nanoparticles Irradiated by Near-Infrared Laser

Fe3O4 nanoparticles (NPs) have been widely used in biomedicine due to their unique magnetism, biocompatibility, and biodegradability. Magnetic hyperthermia of Fe3O4 NPs for cancer treatment has attracted more attention. However, it could interfere with magnetic field-sensitive devices of patients, such as pacemakers. Therefore, it is necessary to find a new method for clinical therapy. In this study, the superparamagnetic Fe3O4 NPs were fabricated. Visible-near-infrared absorption spectra indicated that the Fe3O4 NPs have near-infrared absorption. The influences of Fe3O4 NP concentrations, power density, and wavelength of near-infrared laser irradiation on the photothermal performance of Fe3O4 NPs were investigated. The results revealed that high concentrations, large power density, and short irradiation wavelength could improve the photothermal performance of Fe3O4 NPs. The temperature variation and the absorption intensity simultaneously determined the photothermal transduction efficiency of Fe3O4 NPs. The application of the photothermal performance of Fe3O4 NPs would provide a new opportunity for clinic cancer treatment.

Cytotoxicity to cervical cancer cells of Fe3O4 magnetic nanoparticles coated with cholic acid

This study examined the effect of nanosized ferric oxide (Fe3O4) particles coated with different materials on the toxicity to HeLa cervical cancer cells. Magnetic Fe3O4 nanoparticles were prepared using a solventless thermal decomposition method and coated with either PLGA or CA-PLGA star copolymers. The uptake of nanoparticles by HeLa cells was observed by laser confocal microscopy. The toxicity to HeLa cells of Fe3O4 nanoparticles coated with these two materials was determined by the thiazole blue (MTT) method. The particle size of the single Fe3O4 nanoparticles was about 7 nm, and the PLGA and CA-PLGA nanoparticles loaded with Fe3O4 were spherical, with a particle size of about 200 mm and a theoretical drug loading of 10%. When the mass concentration of Fe3O4 nanoparticles is the same (25 pg/mL), the toxicity of Fe3O4-loaded CA-PLGA nanoparticles to HeLa cells is less than that of the corresponding PLGA nanoparticles. Thus, the CA-PLGA star copolymer can reduce the cytotoxicity of magnetic Fe3O4 nanoparticles and offers potential for broad application in vivo.

Fabrication, characterization and X-band microwave absorption properties of PAni/Fe3O4/PVA nanofiber composites materials

This work presents a study of microwave absorption properties of PAni/Fe3O4/PVA nanofiber composites with different ratio of Fe3O4 nanoparticles. The morphology of the composites nanofibers study by Field Emission Scanning Electron Microscopes (FESEM) and Transmission Electron Microscope (TEM) showed that the low content of Fe3O4 nanoparticles presence in the composites nanofibers indicates very much uniform surface, in the composites nanofiber without many bends, but some bends develop at higher content of Fe3O4 nanoparticles as indicated in the TEM image. Image-J software was used to further investigate the diameter of the composites nanofiber and found to be in the range of 152 to 195 nm. The nanofiber composites show excellent electric and magnetic properties and therefore vary with the addition of Fe3O4 nanoparticles in the composites nanofiber. In addition the PAni/Fe3O4/PVA composites nanofibers were further characterized by X-ray diffraction spectra (XRD) and Four Transformation infrared spectra (FTIR). The XRD pattern shows the presence of PAni nanotubes containing Fe3O4 nanoparticles by indicating peaks at 23.4⁰ and 35.43⁰ which was further supported by FTIR analysis. Microwave vector network analyzers (MVNA) were used to estimate the microwave absorption properties of the composites nanofibers. The absorption parameters was found to be −6.4 dB at 12.9 GHz within the range of X-band microwave absorption frequency, this reflection loss is attributed to the multiple absorption mechanisms as a result of the improved of impedance matching between dielectric and magnetic loss of the absorbent materials demonstrating that these materials can be used as protective material for electromagnetic radiation.

Scanning electron microscopy of bio-fabricated Fe2 O3 nanoparticles and their application to control brown rot of citrus.

Citrus is the leading fruit crop of Pakistan and exported to different parts of the world. Due to suitable weather condition, this crop is affected by different biotic factors which seriously deteriorate its quality and quantity. During the months of November 2018 to January 2019, citrus brown rot symptoms were recurrently observed on sweet oranges in National Agricultural Research Centre (NARC), Islamabad. Causal agent of citrus brown rot was isolated, characterized, and identified as Fusarium oxysporum. For environment-friendly control of this disease, leaf extract of Azadirachta indica was used for the green synthesis of iron oxide (Fe2 O3 ) nanoparticles. These nanoparticles were characterized before their application for disease control. Fourier transform infrared spectroscopy (FTIR) of these synthesized nanoparticles described the presence of stabilizing and reducing compounds like alcohol, phenol, carboxylic acid, and alkaline and aromatic compounds. X-Ray diffraction (XRD) analysis revealed the crystalline nature and size (24 nm) of these nanoparticles. Energy dispersive X-Ray (EDX) analysis elaborated the presence of major elements in the samples. Scanning electron microscopy (SEM) confirmed the spinal shaped morphology of prepared nanoparticles. Successfully synthesized nanoparticles were evaluated for their antifungal potential. Different concentrations of Fe2 O3 nanoparticles were used and maximum mycelial inhibition was observed at 1.0 mg/ml concentration. On the basis of these findings, it could be concluded that Fe2 O3 nanoparticles, synthesized in the leaf extract of A. indica, can be successfully used for the control of brown rot of sweet oranges.

Role of L-cysteine and iron oxide nanoparticle in affecting hydrogen yield potential and electronic distribution in biohydrogen production from dark fermentation effluents by photo-fermentation

Dark fermentation effluent is a potential substrate for hydrogen production by photosynthetic bacteria(PSB). Influences of adding L-cysteine and Fe3O4 nanoparticles (NPs) on hydrogen production performance and electronic distribution from dark fermentation effluents (DFEs) during photo fermentation hydrogen production(PFHP) process were experimentally studied, as well as the critical kinetic analysis. L-cysteine addition can promote flocculability and cell growth rates of PSB HAU-M1 while addition of 300 mg/L L-cysteine and 100 mg/L Fe3O4 NPs can peak H2 yield from the DFEs, resulting in 29.94% and 29.23% substrate electrons were diverted to H2, respectively. Controlling the adding time interval of L-cysteine and Fe3O4 NPs can improve the activity of nitrogenase without weakening flocculation and increase the hydrogen production, the maximum hydrogen yield of 234.55 ± 7.5 mL was obtained at 12 h interval time, 35.94% substrate electrons diverted towards bio-hydrogen generation, and the corresponding nitrogenase activity increased by 2.12 times as comparing to the control. The modified Gompertz and Han-Levenspiel models were employed to model the effect of the L-cysteine and Fe3O4 NPs on hydrogen production, the predicted critical L-cysteine and Fe3O4 NPs concentrations were 4630.87 and 1969.18 mg/L, respectively.

Heat transfer of hybrid nanofluid in a shell and tube heat exchanger equipped with blade-shape turbulators

In the current study, the turbulent forced convection heat transfer of Fe3O4/-CNT/water hybrid nanofluid (HNF) in a heat exchanger (HE) equipped with blade-shape turbulators is studied. The 3D governing equations have been solved numerically with SIMPLEC algorithm and solution domain by employing the control volume method (CVM). The impact of Reynolds number (Re), volume concentration of Fe3O4 nanoparticles (φM) and CNTs (φCNT) and blade-rod diameter (dr) on the performance features of HE are evaluated. The results showed that the PEC of HNF augments with the augmentation of Re and φM, while with intensifying dr, the PEC first rises and then declines. The outcomes showed that the highest PEC occurs at Re = 9000, φM = 0.9%, φCNT = 1.35% and dr = 15mm.

Efficacy of persulfate-based advanced oxidation process (US/PS/Fe3O4) for ciprofloxacin removal from aqueous solutions

Research evidence has shown that pollution of surface and underground waters is the leading sources of environmental and health-related problems. Disposed unused therapeutic drugs have been known to contaminate underground water and also offer drug resistance to infection-causing bacterial. This research seeks to evaluate the use of US/PS/Fe3O4 for the removal of ciprofloxacin (CIP-F) from aqueous solutions. The research also seeks to obtain the optimum set of conditions about which the highest removal efficiency of CIP-F is obtained by monitoring the used pH, Fe3O4 nanoparticles (NPs) concentration, PS concentration, CIP-F concentration, and contact time. The analysis was done using a UV–Vis spectrophotometer (Cecil model CE102) set at 280 nm. The result shows that a 98.43% removal efficiency is achievable after optimization if the separation parameters were set to the optimum conditions (pH = 5, CIP-F concentration = 200 mg/L, PS concentration = 0.15 mol/L, Fe3O4 concentration = 0.01 g/L and contact time = 45 min). The reaction was also observed to follow the pseudo-first-order reaction model. Since the results obtained show that US/PS/Fe3O4 can effectively and efficiently aid the surface adsorption of CIP-F from aqueous solutions, it is therefore recommended based on experimental findings that US/PS/Fe3O4 be used for removing CIP-F from effluents.

Formation-Damage Assessment and Filter-Cake Characterization of Ca-Bentonite Fluids Enhanced with Nanoparticles

SummaryInvasion of mud filtrate while drilling is considered one of the most common sources of formation damage. Minimizing formation damage, using appropriate drilling-fluid additives that can generate good-quality filter cake, provides one of the key elements for the success of the drilling operation. This study focuses on assessing the effect of using different types of nanoparticles (NPs) with calcium- (Ca-) bentonite on the formation-damage and filter-cake properties under downhole conditions.Four types of oxide NPs were added to a suspension of 7-wt% Ca-bentonite with deionized water: ferric oxide (Fe2O3), magnetic iron oxide (Fe3O4), zinc oxide (ZnO), and silica (SiO2) NPs. The NPs/Ca-bentonite suspensions were then used to conduct the filtration process at a differential pressure of 300 psi and a temperature of 250°F using a high-pressure/high-temperature (HP/HT) American Petroleum Institute (API) filter press. Indiana limestone disks of 1-in. thickness were examined as the filter medium to simulate the formation in the filtration experiments. A computed tomography (CT) scan technique was used to characterize the deposited filter cake and evaluate the formation damage that was caused by using different fluid samples.The results of this study showed that the filtrate invasion is affected by the type of NPs, which is also affecting the disk porosity. Using 0.5-wt% Fe2O3 NPs with the 7-wt% Ca-bentonite fluid showed a greater potential to minimize the amount of damage. The average porosity of the disk was decreased by 1.0%. However, adding 0.5-wt% Fe3O4, SiO2, and ZnO NPs yielded a disk-porosity decrease of 4.7, 13.7, and 30%, respectively. The decrease in the disk porosity after filtration is directly proportional to the volume of the invaded filtrate. Compared with that of the base fluid, the best decrease in the filtrate invasion was achieved when adding 0.5 wt% Fe2O3 and Fe3O4 NPs by 42.5 and 23%, respectively. The results revealed that Fe2O3 and Fe3O4 NPs can build a better Ca-bentonite platelet structure and thus a good-quality filter cake. This is because of their positive surface charge and stability in suspensions, as demonstrated by zeta-potential measurements, which can minimize formation damage. Increasing the concentration of Fe3O4 NPs from 0.5% to 1.5 wt% showed an insignificant variation in the filtrate invasion, spurt loss, and filter cake permeability; however, an increase in the filter-cake thickness and amount of damage created was observed. The 1.5-wt% ZnO NPs showed better performance compared with the case having 0.5-wt% ZnO NPs, but in the meanwhile, it showed the lowest efficiency compared with the other types of NPs. This could be because of their surface charge and suspension instability.Results of this work are useful in evaluating the drilling applications using Ca-bentonite-based fluids modified with NPs as an alternative to the commonly used Na-bentonite. In addition, it might help in understanding the NPs/Ca-bentonite interaction for providing more efficient drilling operations and less formation damage.

Cellulose Mediated Transferrin Nanocages for Enumeration of Circulating Tumor Cells for Head and Neck Cancer

Herein we report a hierarchically organized, water-dispersible ‘nanocage’ composed of cellulose nanocrystals (CNCs), which are magnetically powered by iron oxide (Fe3O4) nanoparticles (NPs) to capture circulating tumor cells (CTCs) in blood for head and neck cancer (HNC) patients. Capturing CTCs from peripheral blood is extremely challenging due to their low abundance and its account is clinically validated in progression-free survival of patients with HNC. Engaging multiple hydroxyl groups along the molecular backbone of CNC, we co-ordinated Fe3O4 NPs onto CNC scaffold, which was further modified by conjugation with a protein - transferrin (Tf) for targeted capture of CTCs. Owing to the presence of Fe3O4 nanoparticles, these nanocages were magnetic in nature, and CTCs could be captured under the influence of a magnetic field. Tf-CNC-based nanocages were evaluated using HNC patients’ blood sample and compared for the CTC capturing efficiency with clinically relevant Oncoviu platform. Conclusively, we observed that CNC-derived nanocages efficiently isolated CTCs from patient’s blood at 85% of cell capture efficiency to that of the standard platform. Capture efficiency was found to vary with the concentration of Tf and Fe3O4 nanoparticles immobilized onto the CNC scaffold. We envision that, Tf-CNC platform has immense connotation in ‘liquid biopsy’ for isolation and enumeration of CTCs for early detection of metastasis in cancer.

Cytotoxicity studies of Fe3O4 nanoparticles in chicken macrophage cells.

Magnetic Fe3O4 nanoparticles (Fe3O4-NPs) have been widely investigated for their biomedical applications. The main purpose of this study was to evaluate the cytotoxic effects of different sizes of Fe3O4-NPs in chicken macrophage cells (HD11). Experimental groups based on three sizes of Fe3O4-NPs (60, 120 and 250 nm) were created, and the Fe3O4-NPs were added to the cells at different doses according to the experimental group. The cell activity, oxidative index (malondialdehyde (MDA), superoxide dismutase (SOD) and reactive oxygen species (ROS)), apoptosis and pro-inflammatory cytokine secretion level were detected to analyse the cytotoxic effects of Fe3O4-NPs of different sizes in HD11 cells. The results revealed that the cell viability of the 60 nm Fe3O4-NPs group was lower than those of the 120 and 250 nm groups when the same concentration of Fe3O4-NPs was added. No significant difference in MDA was observed among the three Fe3O4-NP groups. The SOD level and ROS production of the 60 nm group were significantly greater than those of the 120 and 250 nm groups. Furthermore, the highest levels of apoptosis and pro-inflammatory cytokine secretion were caused by the 60 nm Fe3O4-NPs. In conclusion, the smaller Fe3O4-NPs produced stronger cytotoxicity in chicken macrophage cells, and the cytotoxic effects may be related to the oxidative stress and apoptosis induced by increased ROS production as well as the increased expression of pro-inflammatory cytokines.

Recoverable magnetic nanoparticles as hydrate inhibitors

This work investigates a mixed emulsifier system composed of Fe3O4 nanoparticles and Span 20 for the development of reusable hydrate inhibitors. Hydrophobic Fe3O4 nanoparticles were prepared by adsorption of Span 20 on the particle surface, and this was confirmed through UV-absorbance and elemental analysis. Water-in-oil Pickering emulsion droplets with Span 20-adsorbed Fe3O4 nanoparticles were analyzed using a confocal microscope and observed through SEM and EDS mapping of solidified emulsion samples. Due to the physical hindrance of the Span 20-adsorbed Fe3O4 nanoparticles, they can act as both kinetic hydrate inhibitors and anti-agglomerants. The induction time is significantly increased by hindering the nucleation, and the torque is lowered by the anti-adhesive behaviors of the hydrophobic particles. The additional injection of the nanoparticles induces the formation of a capillary water bridge, which increases the contact area and hydrate former supersaturation and reduces the dispersion of the emulsion droplet. Therefore, there would be an optimal concentration of Span 20-adsorbed Fe3O4 nanoparticles which maximizes the inhibition performance. A boot drum separator with a magnetic field shows excellent recovery performance for magnetic hydrate inhibitors with the injection of acetone into the boot separator to break the Pickering emulsions. Overall, the Span 20-adsorbed Fe3O4 nanoparticles provide dual roles as kinetic hydrate inhibitors and anti-agglomerants, providing a new approach for the recovery of hydrate inhibitors with superparamagnetic properties.