Presence Of Fe3O4 Nanoparticles Research Articles

Magnetic nanocomposite through coating mannose-functionalized metal-organic framework with biopolymeric pectin hydrogel beads: A potential targeted anticancer oral delivery system

This study designed magnetic nanocomposite hydrogel beads for a potential targeted anticancer oral delivery system. To end this, nanohybrids of Fe3O4/MIL-88(Fe) (FM) were synthesized through in-situ method by the treatment of terephthalic acid (TPA) and (Fe(NO3)3·9H2O) in the presence of Fe3O4 nanoparticles. They were then modified with mannose sugar as an anticancer receptor to achieve a targeted drug delivery system. After loading methotrexate (MTX), they were coated with pH-sensitive pectin hydrogel beads in the presence of a calcium chloride crosslinker for possible transferring the nanohybrids to the intestine through the acidic environment of the digestive system. The results of different analysis techniques showed that the materials were properly synthesized, coated, and loaded. The designed magnetic nanocomposite hydrogel beads showed pH-sensitive swelling and drug release rate, protecting MTX from the acidic environment of the stomach. MTT test revealed a good cytotoxicity toward colon cancer HT29 cell lines. Remarkably, the functionalization of MTX-loaded FM nanohybrids with mannose (MTX-MFM) enhanced their anticancer properties up to about 20 %. The results recommended that the prepared novel magnetic nanocomposite hydrogel beads have a good potential to be used as a targeted anticancer oral delivery system.

Biohybrid Magnetically Driven Microrobots for Sustainable Removal of Micro/Nanoplastics from the Aquatic Environment

AbstractThe proliferation of micro/nanoplastics derived from the fragmentation of plastic waste released in the environment represents an increasingly alarming issue with adverse implications for aquatic ecosystems worldwide. Conventional approaches for mitigating such contamination are inadequate in removing plastic fragments with exceptionally tiny sizes. Therefore, it is highly urgent to develop efficient strategies to address the threats posed by micro/nanoplastics. Here, biohybrid microrobots, integrating the magnetic properties of Fe3O4 nanoparticles, are investigated for the dynamic removal of micro/nanoplastics from various aquatic environments via high‐precision magnetic actuation and reliable electrostatic interactions. After the surface decoration with Fe3O4 nanoparticles, algae cells can achieve precise locomotion and wireless manipulation by regulating an external magnetic field. Taking advantage of this active movement, magnetic algae robots (MARs) display considerable capture and removal efficiencies for micro/nanoplastics in water with extensive application scenarios. The reusability of MARs is also investigated, proving great recyclable performance. The growth and cell viability experiments elucidate that the presence of Fe3O4 nanoparticles may result in hormesis stimulation of algae growth. Such recyclable microrobots with eco‐friendly and low‐cost characteristics offer an attractive strategy for sustainably tackling micro/nanoplastics pollution.

Stimuli-responsive “theranostic” nanocomposite hydrogels based on β-cyclodextrin containing Fe3O4 and Bi2O3 nanoparticles for targeted delivery of methotrexate

The present study aimed to design and development of novel “theranostic” hydrogels-based drug delivery system (DDSs) composed of beta-cyclodextrin (β-CD), poly(N,N´-dimethylamino)ethyl methacrylate) (PDMAEMA), and Fe3O4 and Bi2O3 nanoparticles (NPs). Methotrexate (MTX) was loaded into the fabricated hydrogels as an anti-cancer drug. Drug encapsulation efficiencies for S1 and S2 samples were obtained as 77.74 and 81 %, respectively. In vitro drug release study verified pH-dependent and sustained drug release behavior of the formulated S1/MTX and S2/MTX. Cytocompatibilities of the hydrogels were approved using MTT-assay on MCF-7 cells. In contrast, the drug-loaded hydrogels showed time- and concentration-dependence cytotoxicities. As MTT-assay results, IC50 in time period of 48 h for free MTX, S1/MTX, and S2/MTX were quantified as 55, 27 and 27 µgmL−1 based on concentration of MTX. Therefore, S1/MTX and S2/MTX possesses higher anti-cancer activities owing to sustained and “smart” release of drug that could reduce drug dosage and side effects. The presence of Fe3O4 NPs and Bi2O3 NPs in the hydrogels allows diagnosis by MRI and CT, respectively. In addition, Bi2O3 NPs is suggested as efficient X-ray radiosensitizer for increasing the efficiency of radiotherapy. Therefore, the fabricated hydrogels have potential for synergistic chemoradiotherapy and can be exploited in medical imaging.

Feasibility of magnetite-poly(n-isopropylacrilamide) smart nanocarriers containing doxorubicin for cancer therapeutic applications

The current study introduces a novel smart magnetic nanocarrier based on poly (n-isopropylacrilamide). Initially, magnetic nanoparticles were synthesized via the co-precipitation method and revealed an average size of 72 ± 10 nm. XRD confirmed the magnetite structure, and VSM showed a saturation magnetization of 69.63 emu/g for the synthesized Fe3O4 magnetic nanoparticles. The optimized nanoparticle was then encapsulated within poly (n-isopropylacrylamide) at 5, 10, and 15 wt%, using an electro-spraying system. A range of techniques were applied to fully characterize the resultant smart magnetic nanocarriers. The FTIR results confirmed the successful loading of doxorubicin drug. Results revealed a faster drug release at higher temperatures, and at an acidic pH (37 °C and pH = 5.1). According to the release profile, 26.6% of the drug release had occurred in an acidic environment, while about 23.2% was detected at pH = 7.1. The presence of Fe3O4 nanoparticles allowed for a more controlled drug release. In vitro studies using MG63 cell line demonstrated non-cytotoxic results for the polymeric nanocarriers, and revealed a reduced cell viability in the presence of doxorubicin, confirming the effectiveness of the nanocarrier. Overall, the results demonstrate the feasibility of the optimized nanocarrier system for cancer therapeutic applications, and highlight its potential for simultaneous chemotherapy and hyperthermia.

Magnetic Nanoparticles Improve Flow Rate and Enable Self-Healing in Covalent Adaptable Networks.

Covalent adaptable networks (CANs) combine the mechanical and chemical stability of thermosets with the reprocessability of thermoplastics through the incorporation of stimuli-responsive dynamic crosslinks. To allow for processing through induction heating, we have created associative CANs that include fillers in the polymer matrix for efficient heat transfer. While the inclusion of inorganic fillers often decreases flow rate in CANs and complicates reprocessing of the material, the presence of Fe3O4 nanoparticles had no detrimental effect on flow behavior in a vinylogous urethane vitrimer, an observation we attribute to the catalytic nature of nanoparticles on the dynamic exchange chemistry. We employed two methods of nanoparticle incorporation: blending bare nanoparticles and crosslinking chemically modified nanoparticles. The vitrimers with covalently crosslinked nanoparticles exhibited a decreased relaxation time compared to those with blended nanoparticles. The magnetic character of the Fe3O4 nanoparticles enabled self-healing of the vitrimer composite materials upon exposure to an alternating electromagnetic field during induction heating.

Solar cells containing two novel superparamagnetic nanocomposites of Fe3O4-TiO2-poly(m-aminobenzenesulfonic acid)

In this paper, two new superparamagnetic nanocomposites of poly(m-aminobenzenesulfonic acid) (PABS), TiO2 and Fe3O4 as inorganic phases were prepared by very simple solid-state polymerization of m-aminobenzenesulfonic acid (m-ABS) and using FeCl3.6H2O as oxidant. These two new nanocomposites used as active layer in new hybrid and magnetic solar cells by FTO/TiO2/nanocomposite/Al structure and they have shown power conversion efficiencies (PCE or η) about 3 % under simulated solar irradiation. The important factors on enhancing the efficiency and the performance of solar cells are the presence of Fe3O4 nanoparticles, SO3- groups and TiO2 (both as a separate layer on FTO and as the inorganic phase in nanocomposites as the active layer). These fabricated solar cells were compared to similar ones and it was observed that the presence of superparamagnetic Fe3O4 nanoparticles can increased the η of solar cells about 200 %. It is due to the effect of the magnetic field, spin-orbit coupling, and/or singlet fission of Fe3O4 that caused increase the triplet excitons population and consequently limit the recombination process. To more study, the photovoltaic parameters under dark were compared with ones obtained under irradiation. The other key features of this article are very simple structure and ease of fabrication of solar cell, green and one-pot synthesis conditions, less fabrication costs and high stability of the compounds. The prepared nanocomposites were characterized using FT-IR, CHNS, XRD, UV–vis, CV, VSM, TGA, IPCE, and I-V analysis. The morphology, conductivity and electrical properties of the nanocomposites were studied. The nanocomposites were electroactive and semiconductor.

Fe3O4 nanoparticles as an efficient catalyst for one-pot synthesis of novel fused phosphorus heterocycles bearing diethyl phosphonate

An efficient and practical method for the synthesis of novel fused phosphorus heterocycles incorporating diethyl phosphonate by the one-pot in the presence of Fe3O4 nanoparticles as a reusable catalyst was achieved. The four-component reactions of ortho-substituted anilines, namely 2-aminophenol, 2-aminothiophenol and 1,2-phenylenediamine with salicylaldehyde, diethyl phosphite and hexaethylphosphorus triamide in the presence of Fe3O4 nanoparticles as a catalyst at 80–90 °C afforded the corresponding 1,3,2-benzo(oxaza/thiaza/diaza)phospholo[2,3-b][1,3,2]benzoxazaphosphinines 1–3 in good yields (80-84%). When the same reactions were repeated by substitution of salicylaldehyde with benzaldehyde, the 1,2-benzazaphospholo[2,1-b][1,3,2]benzo(oxaza/thiaza)phospholes 4 and 5 and 1,3,2-benzodiazaphosphole 6 derivatives were isolated in 78–83% yields. The structures of the synthesized compounds were established by elemental analysis and spectroscopic techniques (IR, MS and NMR).

Efficient Fe3O4 nanoparticle catalysts for depolymerization of polyethylene terephthalate

Polyethylene terephthalate (PET) can be recovered as high-purity bis(2-hydroxyethyl terephthalate) (BHET) monomer by glycolysis in the presence of Fe3O4 nanoparticles (NPs). After removing metallic impurities, BHET can be used to producing r-PET.

Roles of nanoparticles in arsenic mobility and microbial community composition in arsenic-enriched soils

Environmental effects of nano remediation engineering of arsenic (As) pollution need to be considered. In this study, the roles of Fe2O3 and TiO2 nanoparticles (NPs) on the microbial mediated As mobilization from As contaminated soil were investigated. The addition of Fe2O3 and TiO2 NPs restrained As(V) release, and stimulated As(III) release. As(V) concentration decreased by 94% and 93% after Fe2O3 addition, and decreased by 89% and 45% after TiO2 addition compared to the Biotic and Biotic+Acetate (amended with sodium acetate) controls, respectively. The maximum values of As(III) were 20.5 and 27.1 µg/L at 48 d after Fe2O3 and TiO2 NPs addition, respectively, and were higher than that in Biotic+Acetate control (12.9 µg/L). The released As co-precipitated with Fe in soils in the presence of Fe2O3 NPs, but adsorbed on TiO2 NPs in the presence of TiO2 NPs. Moreover, the addition of NPs amended with sodium acetate as the electron donor clearly promoted As(V) reduction induced by microbes. The NPs addition changed the relative abundance of soil bacterial community, while Proteobacteria (42.8%-70.4%), Planctomycetes (2.6%-14.3%), and Firmicutes (3.5%-25.4%) were the dominant microorganisms in soils. Several potential As/Fe reducing bacteria were related to Pseudomonas, Geobacter, Desulfuromonas, and Thiobacillus. The addition of Fe2O3 and TiO2 NPs induced to the decrease of arrA gene. The results indicated that the addition of NPs had a negative impact on soil microbial population in a long term. The findings offer a relatively comprehensive assessment of Fe2O3 and TiO2 NPs effects on As mobilization and soil bacterial communities.

Engineered magnetic plant biobots for nerve agent removal

Biohybrid micro/nanorobots that integrate biological entities with artificial nanomaterials have shown great potential in the field of biotechnology. However, commonly used physical hybridization approaches can lead to blockages and damage to biological interfaces, impeding the optimal exploitation of natural abilities. Here, we show that magnetically propelled plant biobots (MPBs), employing tomato-callus cultivation engineering in the presence of Fe3O4 nanoparticles (NPs), are capable of active movement and directional guidance under a transversal rotating magnetic field. The Fe3O4 NPs were transported through the cell growth media and then taken up into the plant tissue cells (PTCs), imparting the plant biobot with magnetic function. Moreover, Fe ions support the growth of callus cells, resulting in nanoparticle incorporation and enabling faster growth and structurally compact texture. The magnetic plant biobots demonstrated rapid and efficient removal of chlorpyrifos (approximately 80%), a hazardous nerve gas agent that causes severe acute toxicity, and recovery using an external magnetic field. The eco-friendly plant biobots described here demonstrate their potential in biomedical and environmental applications.

Seawater desalination by coupling cyclopentane hydrate formation and capacitive deionization processes in the presence of Fe3O4 nanoparticles and magnetic field

This study investigates seawater desalination by coupling cyclopentane hydrate formation and capacitive deionization processes. High induction time, low conversion of water to hydrate, and low ion removal efficiency are the challenges of the hydrate desalination process. In order to reduce the cost of hydrate formation, cyclopentane was used as a hydrate former. Also, the promotion effects of Fe3O4 nanoparticles and magnetic field on the cyclopentane hydrate formation in pure water, seawater, and synthetic saline waters containing NaCl, KCl, CaCl2, and MgCl2 at different concentrations were investigated. The results showed that the Fe3O4 nanoparticles and magnetic field could improve the hydrate formation and the effect of Fe3O4 nanoparticles is greater than the magnetic field. However, the promoting effect on the induction time and removal efficiency was intensified when the Fe3O4 nanoparticles and the magnetic field were used simultaneously. The results of hydrate formation in seawater showed that the induction time in the presence of 0.07 wt.% Fe3O4 nanoparticles, magnetic field, and simultaneous use of both of them were reduced by 89, 22, and 92%, respectively. The ion removal efficiency reached 79% for Na+ and higher than 99% for K+, Ca2+, and Mg2+ when capacitive deionization was used as post-treatment.

Superhydrophobic starch-based cryogels modified with silylated magnetic nanoparticles for oil spill cleanup

Superhydrophobic smart adsorbents have attracted wide attention for the cleanup of oil spill that endangers the aquatic ecosystem. Herein, a super-water-repellent coating (HOS/Fe3O4) was achieved through hydrolytic condensation of hexadecyltrimethoxysilane and tetraethyl orthosilicate in the presence of Fe3O4 nanoparticles. The coating was then introduced onto the surface of starch cryogel (SC) by spray-coating technique to fabricate the superhydrophobic and magnetic starch-based adsorbent (HOS/Fe3O4@SC). The surface chemical composition and hierarchical micro/nanostructures that contribute to the high water contact angle (>151°) and low sliding angle (<5°) of the as-obtained material were characterized in detail. The HOS/Fe3O4@SC exhibited excellent water repellent, self-cleaning, and anti-fouling properties. The structural support and stable chemical bonding endow the material with good mechanical and chemical durability. The HOS/Fe3O4@SC also possessed reasonable adsorption capacities to various organic solvents, and its oil absorption kinetics was also comprehensively studied. The HOS/Fe3O4@SC can be applied for heavy oil absorption underwater and magnetically guided oil slick cleaning. This novel starch-based absorbent exhibits promising application in tackling oil contamination in complex environments.

Microwave-assisted facile synthesis of layered reduced graphene oxide-tungsten disulfide sandwiched Fe3O4 nanocomposite as effective and sensitive sensor for detection of dopamine

The exceptional properties of two-dimensional (2D) organic/inorganic layered materials make them a promising candidate for use in electrochemical sensing application. In this research study, the combination of two different layered materials as reduced graphene oxide (rGO) nanosheets and tungsten disulfide (WS2) separated by Fe3O4 nanoparticles, have been synthesized by microwave irradiation method for the detection of dopamine. Microwave-assisted synthesis of heterostructure rGO-WS2@Fe3O4 nanocomposite is a simple, cost-effective, high-yield and short-reaction time approach. The phase formation, surface morphology and structural properties of the nanocomposite show that the presence of Fe3O4 nanoparticles in between separated layers of rGO and WS2 nanosheets prevent the agglomeration of nanoparticles as well as the restacking of the 2D layered materials. Due to well-defined morphologies and crystallinity, as-synthesized rGO-WS2@Fe3O4 nanocomposite was used as an efficient biosensor for the detection of dopamine, a neurotransmitter. The rGO-WS2@Fe3O4 nanocomposite was found to show a low limit of detection (LOD) i.e., 2.74 μM with the sensitivity of 3.18 μA μM−1 cm−2 for dopamine at a low potential of 0.2 V. Therefore, it is expected that the microwave-assisted cost-effective route can be developed for rGO combined with other inorganic layered materials to design electrochemical sensors for the determination of biological and pharmaceutical samples.

Magnetite-induced topological transformation of 3D hierarchical MgAl layered double hydroxides to highly dispersed 2D magnetic hetero-nanosheets for effective removal of cadmium ions from aqueous solutions

The study shows the synthesis of highly dispersed magnetic hetero-nanosheets through topological transformation of 3D Hierarchical MgAl layered double hydroxides in the presence of Fe3O4 nanoparticles. The platelet-like hierarchical nano-heterostructures consisted of 10 nm Fe3O4 magnetic nanoparticles dispersed over the surface of MgAl-LDH lamella. The as-prepared biphasic self-assembled nanocomposite was successfully used as an adsorbent for decontamination of spiked cadmium wastewater at room temperature. A comprehensive physico-chemical characterization of structural and textural features, as well as the magnetic properties of the prepared nanocomposites were carried out by using complementary techniques such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometer (XRD), vibrating sample magnetometer (VSM), Dynamic light scattering (DLS) analysis, Brunauer-Emmett-Teller (BET) surface area and Zeta potential respectively. Moreover, the influences of certain parameters including pH, adsorbent dosage, initial cadmium concentration, and contact time were extensively studied in terms of profiling the adsorption capacity of the hierarchical nano-heterostructures. Different adsorption isotherm (Langmuir, Freundlich, Temkin, and Redlich-Peterson) in linear and nonlinear forms were applied. According to the results, Freundlich and Redlich-Peterson models fitted the data. On the other hand, three kinetic models were used, including pseudo-first order, pseudo-second order (linear and nonlinear forms), and intraparticle diffusion.The results were explained through a pseudo-second-order model, reaching the equilibrium in 60 min. The optimum recommended pH and adsorbent dose are 5 and 1.4 g/L, respectively. Comprehensive characterization revealed that the synthesized materials are suitable candidates as adsorbents in Cd (II) adsorption techniques with maximum adsorption capacities of 80.6 mg/g, 91.7 mg/g, and 109.9 mg/g. Furthermore, the regeneration investigation highlighted the adsorbents' performance after three cycles of adsorption/desorption.

Reduction of ZnO nanoparticles toxicity to methanogenic wastewater treatment by the presence of Fe3O4 nanoparticles: Focusing on nanomaterial interaction and direct interspecies electron transfer

The extensive production and wide use of ZnO and Fe3O4 nanoparticles (NPs) potentially leads to their synchronous release into the environment, and the exposure of ZnO NPs can inhibit the methanogenic process. This study investigated the effect of Fe3O4 NPs on the toxicity of ZnO NPs to methanogenesis of wastewater and the related mechanism. It was observed that the presence of 50 mg/L Fe3O4 NPs entirely mitigated the inhibition caused by 100 mg/L ZnO NPs, which had been decreased by 39.0% compared with the control group. This was because that ZnO NPs induced the accumulation of short-chain fatty acid, deterioration of extracellular polymeric substances, low activities of acetate kinase and coenzyme F420, low levels of intracellular NADH/NAD+ and ATP, and even the death of methanogenic Archaea. However, all these suppressed activities were recovered when co-presence of Fe3O4 NPs. Moreover, Fe3O4 NPs not only suppressed the levels of hydrogenase and c-type cytochrome but also enriched the direct interspecies electron transfer (DIET)-linking partners, suggesting a lower interspecies hydrogen transfer and higher DIET activities occurred. The investigations of NPs interactions demonstrated that the agglomeration of NPs, the decrease of Zn2+ and release of Fe2+ were primarily responsible for the reduced toxicity of ZnO NPs.

Fe3O4 nanoparticles-mediated solar-driven enzymatic PET degradation with PET hydrolase

Cost-effective and eco-friendly treatment or recycled use of poly (ethylene terephthalate) (PET) is highly desired. Enzymatic PET degradation is considered a promising approach, but currently available PET hydrolases (PETases) have low activity at ambient temperature. Thus, elevating the reaction system temperature in a cost-effective way becomes a key to the economical enzymatic PET degradation. Herein, we proposed solar-driven enzymatic PET degradation with DuraPETase, a stable mutant of PETase, by using Fe3O4 nanoparticles (NPs) as the solar-to-thermal agent. Simulated solar irradiation could elevate the suspension of Fe3O4 NPs from 25 °C to 46 °C for the effective PET degradation. The enzyme immobilized onto Fe3O4 NPs, DuraPETase@Fe3O4, had higher stability than free DuraPETase, but a 10-d PET degradation experiments under simulated solar irradiation revealed that free DuraPETase in the presence of Fe3O4 NPs was approximately three times more effective than the DuraPETase@Fe3O4 system because of the superiority of free DuraPETase in degrading PET. This implies that enzyme immobilization is unnecessary in such a single-use system. By contrast, the DuraPETase-only system showed only 15.5% efficiency of the Fe3O4-mediated solar-driven system with free DuraPETase. The research demonstrated the potential of the Fe3O4-mediated solar-driven enzymatic PET degradation strategy for further development in different practical scenarios

Electromagnetic Shielding Effectiveness of Glass Fiber/Epoxy Laminated Composites with Multi-Scale Reinforcements

In this study, an experimental investigation has been performed to understand the electromagnetic interference-shielding effectiveness (EMI-SE) of glass fiber/epoxy laminated composites embedded with carbon nanotubes (CNTs) and Fe3O4 nanoparticles, reinforced with micro carbon fibers along the thickness direction. Micro carbon fibers were reinforced along the thickness direction between the laminates using an electro-flocking process and a vacuum infusion process used to fabricate the composites. The EMI-SE of the composites was measured in the X-band frequency range (8–12 GHz). The effect of carbon fibers of three different lengths (80 µm, 150 µm, and 350 µm) with two different fiber densities (1000 and 2000 fibers/mm2) and two different amounts of Fe3O4 nanoparticles (0.5 and 1 wt.%) on total SE, absorption, and reflection was investigated. Due to the synergetic effect of Fe3O4 nanoparticles, CNTs, and carbon fibers, the final EMI shielding of the composites was mainly dominated by the absorption process. The absorption was more pronounced in the composites of longer carbon fibers with improved electrical conductivity. The presence of Fe3O4 nanoparticles also enhanced total SE values with improved magnetic permeability. The composite with micro carbon fibers of 350 µm length and 2000 fibers/mm2 density with 1 wt.% of Fe3O4 nanoparticles showed the maximum value of total SE.

Influence of Fe3O4 and CTABr on the Rate of Degradation of Methylene Blue by H2O2

The kinetics of the oxidation of methylene blue (MB) by H2O2 in the presence of iron oxide nanoparticles has been studied. The nanoparticles of iron oxide (Fe3O4) were synthesized and characterized physico-chemical techniques. The XRD studies showed its crystalline nature. The VSM study was carried out to determine the values of the magnetic saturation parameter ~ 40.00 emu/g. The particle were of spherical shape with particle size distribution centered at 12 ± 2 nm. The FT-IR spectra indicated the presence of peaks at 585 cm -1 and 459 cm -1 due to Fe-O bond vibrations. The peak at 3424 cm -1 was assigned to the O-H stretching vibration. The H-O-H bending appeared at 1631 cm -1 . The Fe3O4 nanoparticles enhanced the rate of degradation of MB. The oxidation rate increased with the increase in Fe3O4. At pH 3, the maximum rate of oxidation of MB was observed. The rate of reaction increased with the increase in [H2O2] in the absence of Fe3O4. But in the presence of Fe3O4, the rate constant versus [H2O2] showed peaked behaviour. The CTABr increased the rate of oxidation of MB by H2O2 in the presence of Fe3O4 nanoparticles.

Synthesis of Graphitic Carbon Nitride on the Surface of Fe3O4 Nanoparticles

A composite material consisting of graphitic carbon nitride and iron(II,III) oxide (g-C3N4/Fe3O4) and having photocatalytic and magnetic properties has been synthesized via single-step thermal decomposition of melamine in the presence of Fe3O4 nanoparticles. It has been shown that, at synthesis temperatures in the range 400–500°C, Fe2+ ions do not oxidize, and the Fe3O4 particles retain their crystal structure and ferromagnetic properties, but the process involves the formation of crystalline g-C3N4 as well. The maximum in the intensity of photoluminescence bands of the g-C3N4/Fe3O4 composite material is shifted to lower photon energies compared to g-C3N4 prepared without Fe3O4 particles under the same synthesis conditions, which is due to a decrease in its band gap, formed by a system consisting of C–N π bonds with sp2 hybridization. The magnetic properties of g-C3N4/Fe3O4 composite particles allow them to be readily recovered from liquids for reuse.

MTX-Loaded Dual Thermoresponsive and pH-Responsive Magnetic Hydrogel Nanocomposite Particles for Combined Controlled Drug Delivery and Hyperthermia Therapy of Cancer.

In recent years, the exploitation of magnetic nanoparticles in smart polymeric matrices have received increased attention in several fields as site-specific drug delivery systems. Here, ultrasonic-assisted emulsion copolymerization of N-isopropylacrylamide (NIPAM) and 2-(N,N-diethylaminoethyl) methacrylate (DEAEMA) in the presence of Fe3O4 nanoparticles was employed to prepare pH- and temperature-responsive magnetite nanocomposite particles (MNCPs). The obtained MNCPs were fully characterized by TEM, DSC, FT-IR, VSM, and XRD techniques. They had an average particle size of 70 nm with a lower critical solution temperature of 42 °C and superparamagnetic properties. In addition, MNCPs were loaded with methotrexate (MTX) as an anticancer drug, and their in vitro drug release was studied in different pH values and temperatures and in the presence of an alternating magnetic field. Noteworthy that the highest rate of MTX release was observed at pH 5.5 and 42 °C. Cell viability of the treated MCF-7 human breast cancer cell line with free MTX, MNCPs, and MTX-loaded MNCPs or in combination with magnetic hyperthermia (MHT) and water-based hyperthermia was comparatively studied. The obtained results showed about 17% higher antiproliferative activity for the MTX-loaded MNCPs accompanied by MHT relative to that of free MTX.