Magnetic Iron Oxide Research Articles

Development of tungsten-modified iron oxides to decompose an over-the-counter painkiller, Acetaminophen by activating peroxymonosulfate

Acetaminophen (APAP) is a well-known type of over-the-counter painkillers and is frequently found in surface waterbodies, causing hepatotoxicity and skin irritation. Due to its persistence and chronic effects on the environment, innovative solutions must be provided to decompose APAP, effectively. Innovative catalysts of tungsten-modified iron oxides (TF) were successfully developed via a combustion method and thoroughly characterized using SEM, TEM, XRD, XPS, a porosimetry analysis, Mössbauer spectroscopy, VSM magnetometry, and EPR. With the synthesis method, tungsten was successfully incorporated into iron oxides to form ferrites and other magnetic iron oxides with a high porosity of 19.7 % and a large surface area of 29.5 m2/g. Also, their catalytic activities for APAP degradation by activating peroxymonosulfate (PMS) were evaluated under various conditions. Under optimal conditions, TF 2.0 showed the highest APAP degradation of 95 % removal with a catalyst loading of 2.0 g/L, initial APAP concentration of 5 mg/L, PMS of 6.5 mM, and pH 2.15 at room temperature. No inhibition by solution pHs, alkalinity, and humic acid was observed for APAP degradation in this study. The catalysts also showed chemical and mechanical stability, achieving 100 % degradation of 1 mg/L APAP during reusability tests with three consecutive experiments. These results show that TFs can effectively degrade persistent contaminants of emerging concern in water, offering an impactful contribution to wastewater treatment to protect human health and the ecosystem.

Influence of the iron-oxide mass fractions of magnetic powdered activated carbon on its hexavalent chromium adsorption performance in water

Magnetic powdered activated carbon (Mag-PAC) is an effective adsorbent to remove hexavalent chromium (Cr(VI)) from water and can be recovered for reuse. However, the tradeoff between the adsorption performance of Cr(VI) and magnetic properties of Mag-PAC remains unclear. Herein, we prepared a series of Mag-PAC adsorbents containing various iron-oxide mass fractions with FeSO4·7H2O as the precursor, using a facile wet-chemical precipitation route and conducted batch experiments to evaluate the Cr(VI) adsorption performance. Results revealed that Mag-PAC was functionalized by magnetic iron oxide comprising crystalline goethite and magnetite structures. Furthermore, its adsorption performance was highly dependent on pH and was most effective at an initial solution pH of 2. Both the sorption rate constant and Cr(VI) adsorption capacity were greatly influenced by magnetization, and they gradually decreased as the iron-oxide mass fraction increased. Among the prepared adsorbents, Mag-PAC-75 (∼32% wt iron) exhibited not only an excellent Cr(VI) adsorption performance (Langmuir adsorption capacity: 75.76 mg/g) but also effective magnetic properties (saturation magnetization: 9.66 emu/g). Coexisting anions had a negligible competitive effect on Cr(VI) removal by Mag-PAC-75 at an initial pH of 2, whereas the presence of tannic acid markedly improved the Cr(VI) elimination. The presence of trivalent chromium on the surface of Mag-PAC-75 confirmed via X-ray photoelectron spectroscopy indicated that some synergistic redox reactions may occur during the sorption process. After five regeneration cycles using NaOH, Mag-PAC-75 continued to exhibit a high Cr(VI) removal efficiency and magnetic stability. These findings indicate that optimizing the adsorption performance and magnetic properties is a key factor for realizing the practical application of Mag-PAC for Cr(VI) removal. Overall, Mag-PAC may have been a promising application prospect for Cr(VI) removal from water due to its high adsorption capacity and magnetic properties, coupled with its good reusability and magnetic stability after regeneration cycles.

Boosting ferroptosis by intervention of redox balance and synergetic with photothermal/photodynamic therapy for suppression of pancreatic cancer

Metal-doped iron oxide nanoparticles have attracted increasing attention for their Fenton reaction ability, which converts H2O2 to cytotoxic reactive oxygen species (ROS) and is recently utilized as ferroptosis activator in pancreatic cancer therapy. However, low intracellular H2O2 level hinders ferroptosis effect and leads to unsatisfactory efficacy. Herein, a transferrin coated and tumor homing peptide decorated bimetallic magnetic nanoparticles copper-doped iron oxide nanosystems embedded with photothermal agent IR820 and iron ions (denoted as PCTIFL) is constructed for synergistic treatment for pancreatic cancer by combining ferroptosis and photothermal/photodynamic therapy (PTT/PDT) under 808 nm laser irradiation. Benefiting from the homologous targeting property of LyP-1, the nanosystems can be precisely delivered and gradually accumulate at tumor site. For the synergistic therapy, IR820 generates ROS via photodynamic effect and enables cancer cell temperature elevation via PTT effect upon 808 nm laser irradiation on the one hand and metal ions such as Fe2+, Fe3+ and Cu2+ catalyze H2O2 into ROS and finally triggered ferroptosis on the other hand. Moreover, PCTIFL nanosystems can be applied in pancreatic cancer diagnosis for their MRI/NIR dual imaging function. Overall, this work not only presents a promising strategy for augmenting the ferroptosis induced by iron oxide, but also a fantastic paradigm for pancreatic cancer diagnosis and synergistic therapy.

Removal of lead and cadmium ions from water using primary-secondary amine modified magnetic microbeads: Equilibrium, kinetic, and thermodynamic studies

This study developed novel magnetic microbeads based on trimethoxysilylpropylethylenediamine (TSD) as a primary-secondary amine source through a one-pot process. The process involves coating magnetic iron oxide nanoparticles (MNPs) with primary-secondary amine (TSD), followed by cross-linking with alginate (Alg). The ternary magnetic microbeads (Alg@MTSD) were used to remove Pb2+ and Cd2+ ions from aqueous media. The nanocomposite was characterized using various techniques, including Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and vibrating sample magnetometry (VSM). Adsorption experiments were conducted under optimal conditions, and isothermal models, including Langmuir and Freundlich, as well as kinetic models, were applied to evaluate the experimental data. The findings indicated that the Langmuir model best fit the adsorption data for Pb2+ and Cd2+ ions, with R2 > 0.99. The maximum adsorption capacities were 68 mg·g−1 for Pb2+ and 51 mg·g−1 for Cd2+. Kinetic studies showed that the adsorption process followed the pseudo-second-order model. Thermodynamic analysis suggested that the adsorption mechanism was physisorption.

Negative Regulators, TUP1, NRG1, and TOR1: Possible Molecular Targets of Antibiofilm Activity of Nano-Fe3 O4 in Candida albicans

Background: Candida albicans is an opportunistic pathobiont that manifests as candidiasis. Drug-resistant biofilms hinder current treatment of candidiasis. The morphological control of filamentous growth and biofilm formation is vital for the pathogenicity of C. albicans. This study aimed to investigate the antifungal activity of magnetic iron oxide nanoparticles (nano-Fe3 O4 ) against C. albicans, their ability to inhibit pre-formed biofilms, and to examine the expression levels of negative regulators, transcriptional repressors thymidine uptake 1 (TUP1), the negative transcriptional regulator of glucose repressed genes (NRG1), and target of rapamycin (TOR1) in C. albicans pre-formed biofilms after treatment with nano-Fe3 O4 . Methods: This study examines the antifungal activity of nano-Fe3 O4 against C. albicans, its ability to inhibit pre-formed biofilms, and investigates the expression levels of negative regulators, TUP1, NRG1, and TOR1 in C. albicans pre-formed biofilms after treatment with nano-Fe3 O4 . Results: Nano-Fe3 O4 at concentrations of 2× minimum inhibitory concentration (MIC), 1× MIC, and ½× MIC showed significant inhibitory effects on C. albicans pre-formed biofilm formation by 2,3-bis (2-methoxy-4-nitro-5 sulfophenyl)-5-[(phenylamino) carbonyl])-2H-tetrazolium hydroxide (XTT), crystal violet staining and light field microscopy with a MIC of 50 μg/mL. Gene expression profiling showed that nano-Fe3 O4 upregulates targets TUP1, NRG1, and TOR1 in C. albicans pre-formed biofilms. Conclusion: Our results suggest that nano-Fe3 O4 diminishes pre-formed biofilms and may subsequently reduce the pathogenicity of C. albicans, which can be responsible for biofilm-associated infections. TUP1, NRG1, and TOR1 may be possible molecular targets in C. albicans pre-formed biofilms after treatment with nano-Fe3 O4.

Fabrication of magnetic carbohydrate-modified iron oxide nanoparticles (Fe3O4/pectin) decorated with bimetallic Co/Cu-MOF as an effective and recoverable catalyst for the Biginelli reaction.

Due to their biocompatibility, facile recoverability, mechanical and thermal stability, high surface area, and active catalytic sites, magnetic nanocomposites, containing natural polymers and magnetic nanoparticles, have been used to produce supports for catalysts or biocatalysts. Pectin, an important polycarbohydrate, has abundant functional groups with excellent ability to coat the surface of the nanoparticles to fabricate composite and hybrid materials. A novel bimetallic cobalt(ii) and copper(ii)-based metal-organic framework (Co/Cu-MOF) immobilized pectin-modified Fe3O4 magnetic nanocomposite was designed and fabricated. Fe3O4 nanoparticles were modified in situ by pectin and, subsequently, used as a support for growing Co/Cu-MOF [Fe3O4/pectin/(Co/Cu)MOF]. The properties of the nanocomposite were investigated by FT-IR, XRD, SEM, EDS, VSM, STA, and BET. The nanocomposite exhibited both magnetic characteristics and a high surface area, making it a suitable candidate for catalytic applications. Then, the Fe3O4/pectin/(Co/Cu)MOF nanocomposite was utilized in the Biginelli reaction for the production of biologically active dihydropyrimidinones. Due to paramagnetism, Fe3O4/pectin/(Co/Cu)MOF was easily recovered and reused in six cycles without significant loss in reactivity. This green method comprises several benefits, such as mild reaction conditions, free-solvent media, high yields, easy workup, short reaction times and reusability of the prepared catalyst.

Novel Directed Enzyme Prodrug Therapy for Cancer Treatment Based on 2'-Deoxyribosyltransferase-Conjugated Magnetic Nanoparticles.

Directed enzyme prodrug therapy (DEPT) strategies show promise in mitigating chemotherapy side effects during cancer treatment. Among these, the use of immobilized enzymes on solid matrices as prodrug activating agents (IDEPT) presents a compelling delivery strategy, offering enhanced tumor targeting and reduced toxicity. Herein, we report a novel IDEPT strategy by employing a His-tagged Leishmania mexicana type I 2'-deoxyribosyltransferase (His-LmPDT) covalently attached to glutaraldehyde-activated magnetic iron oxide nanoparticles (MIONPs). Among the resulting derivatives, PDT-MIONP3 displayed the most favorable catalyst load/retained activity ratio, prompting its selection for further investigation. Substrate specificity studies demonstrated that PDT-MIONP3 effectively hydrolyzed a diverse array of 6-oxo and/or 6-amino purine 2'-deoxynucleosides, including 2-fluoro-2'-deoxyadenosine (dFAdo) and 6-methylpurine-2'-deoxyribose (d6MetPRib), both well-known prodrugs commonly used in DEPT. The biophysical characterization of both MIONPs and PDT-MIONPs was conducted by TEM, DLS, and single particle ICPMS techniques, showing an ideal nanosized range and a zeta potential value of -47.9 mV and -78.2 mV for MIONPs and PDT-MIONPs, respectively. The intracellular uptake of MIONPs and PDT-MIONPs was also determined by TEM and single particle ICPMS on HeLa cancer cell lines and NIH3T3 normal cell lines, showing a higher intracellular uptake in tumor cells. Finally, the selectivity of the PDT-MIONP/dFAdo IDEPT system was tested on HeLa cells (24 h, 10 µM dFAdo), resulting in a significant reduction in tumoral cell survival (11% of viability). Based on the experimental results, PDT-MIONP/dFAdo presents a novel and alternative IDEPT strategy, providing a promising avenue for cancer treatment.

Earth-Abundant Recyclable Magnetic Iron Oxide Nanoparticles for Green-light Mediated C-H Arylation in Heterogeneous Phase.

A magnetically isolable iron oxide nanoparticles is introduced as an efficient heterogeneous photocatalyst for non-directed C-H arylation employing aryl diazonium salts as the aryl precursors. This first-row transition metal-based photocatalyst revealed versatile activities and is applicable to a wide range of substrates, demonstrating brilliant efficacy and superior recyclability. Detailed catalytic characterization describes the physical properties and redox behavior of the Fe-catalyst. Adequate control experiments helped to establish the radical-based mechanism for the C-H arylation.

Emerging Trends in Targeted Magnetic Nanoparticle Imaging for Precision Medicine in Oncology

In cancer care's dynamic landscape, targeted imaging is pivotal for advancing precision medicine. This review focuses on the role of magnetic nanoparticles (MNPs), particularly magnetic iron oxide nanoparticles (MIONPs) and superparamagnetic iron oxide nanoparticles (SPIONs), in personalized diagnostics and treatments for oncology. Current trends and future directions in MNP imaging, addressing challenges like biocompatibility, toxicity, and regulatory considerations, are discussed. The review explores MIONPs' theranostic potential, especially in brain drug delivery monitoring through magnetic resonance imaging (MRI) or magnetic particle imaging (MPI). Variousnanoparticle types, including SPIONs as MRI contrast agents, are highlighted. The article covers challenges in nanoparticle modification, including methoxy- polyethylene glycol (mPEG), and discusses gold nanoparticles (AuNPs) for photoacoustic imaging, as well as insights into fluorescent semiconductor quantum dots (QDs). The conclusion emphasizes rapid and accurate tumoridentification, introduces carbon nanotubes (CNTs) for cancer therapy and diagnosis, and underscores the transformative role of lipid-based nanocarriers incancer research. The multifaceted applications of nanotechnology in cancer diagnostics and treatment are discussed throughout, showcasing a paradigm shift.Crucial challenges in unlocking nanotechnology's full potential in cancer care, such as safety concerns, robust clinical trials, synthesis methods standardization, regulatory approval, biodegradability, tailoring nanotherapies, economic viability, ethical considerations, and interdisciplinary collaboration, are addressed. Addressing these challenges holds the promise of elevating nanotechnology into a potent force in the ongoing battle against cancer.

Raman spectroscopic investigation of polymer based magnetic multicomponent scaffolds

Scaffolds acting as an artificial matrix for cell proliferation are one of the bone tissue engineering approaches to the treatment of bone tissue defects. In the presented study, novel multicomponent scaffolds composed of a poly(ε-caprolactone) (PCL), phenolic compounds such as tannic (TA) and gallic acids (GA), and nanocomponents such as silica-coated magnetic iron oxide nanoparticles (MNPs-c) and functionalized multi-walled carbon nanotubes (CNTs) have been produced as candidates for such artificial substitutes. Well-developed interconnected porous structures were observed using scanning electron microscopy (SEM). Raman spectra showed that the highly crystalline nature of PCL was reduced by the addition of nanoadditives. In the case of scaffolds containing MNPs-c and TA, the formation of a Fe-TA complex was concluded because characteristic bands of chelation of the Fe3+ ion by phenolic catechol oxygen appeared. It was found that the necessary conditions for the crystallization of the PCL/MNPs-c/TA are for the catechol groups to be able to penetrate the porous silica shell of MNPs-c, as during experiment with MNPs-c and TA without polymer, no such complexation was observed. Moreover, the number of catechol groups, the spatial structure and molecular size of this phenolic compound are also crucial for complexation process because GA does not form complexes. Therefore, the PCL/CNTs/MNPs-c/TA scaffolds are interesting candidates to consider for their possible medical applications.

Novel magnetic iron oxide-dextran sulphate nanocomposites as potential anticoagulants: Investigating interactions with blood components and assessing cytotoxicity

Examining the critical role of anticoagulants in medical practice, particularly their central function in preventing abnormal blood clotting, is of the utmost importance. However, the study of interactions between blood proteins and alternative anticoagulant nano-surfaces is still understood poorly. In this study, novel approach involving direct functionalisation of magnetic iron oxide nanoparticles (MNPs) as carriers with sulphated dextran (s-dext) is presented, with the aim of evaluating the potential of magnetically-responsive MNPs@s-dext as anticoagulants. The physicochemical characterisation of the synthesised MNPs@s-dext includes crystal structure analysis, morphology study, surface and electrokinetic properties, thermogravimetric analysis and magnetic properties` evaluation, which confirms the successful preparation of the nanocomposite with sulfonate groups. The anticoagulant potential of MNPs@s-dext was investigated using a standardised activated partial thromboplastin time (APTT) test and a modified APTT test with a quartz crystal microbalance with dissipation (QCM-D) which confirmed the anticoagulant effect. Time-resolved solid-liquid interactions between the MNPs@s-dext and model blood proteins bovine serum albumin and fibrinogen were also investigated, to gain insight into their hemocompatibility, and revealed protein-repellence of MNPs@s-dext against blood proteins. The study also addressed comprehensive cytotoxicity studies of prepared nanocomposites, and provided valuable insights into potential applicability of MNPs@s-dext as a promising magnetic anticoagulant in biomedical contexts.

Development and characterization of magnetic-based biodegradable periodic mesoporous organosilica nanoparticles for enhanced biomedical applications

Herein, magnetic-based biodegradable periodic mesoporous organosilica (BPMO) nanoparticles were successfully synthesized via a co-precipitation method to form a magnetic iron oxide (Fe3O4) core, followed by the condensation of organosilica precursors to produce BPMO shells. The physicochemical properties of the resulting hybrid nanoparticles were evaluated using powder X-ray diffraction, nitrogen adsorption–desorption isotherms, thermogravimetric analysis, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. The synthesized particles exhibited a spherical morphology with an average diameter of approximately 250 nm. A core–shell structure was formed by depositing a 100-nm biodegradable organosilica layer onto the magnetic Fe3O4 cluster, endowing the nanoparticles with both magnetic and biodegradable mesoporous characteristics. Notably, despite the silica coating, the saturation magnetization remained high, reaching 35.8 emu/g, suggesting the potential for using these nanoparticles in magnetic-based biomedical applications. Furthermore, Fe3O4@BPMO nanoparticles were demonstrated to be efficiently uptaken by OVCAR8 ovarian cancer cells and spheroids, indicating that these nanoparticles are promising as magnetic nanocarriers for anti-cancer drug delivery and can be used in magnetic resonance imaging and magnetic hyperthermia.

Magnetically Induced Thermal Effects on Tobacco Mosaic Virus-Based Nanocomposites for a Programmed Disassembly of Protein Cages.

Protein cages are promising tools for the controlled delivery of therapeutics and imaging agents when endowed with programmable disassembly strategies. Here, we produced hybrid nanocomposites made of tobacco mosaic virus (TMV) and magnetic iron oxide nanoparticles (IONPs), designed to disrupt the viral protein cages using magnetically induced release of heat. We studied the effects of this magnetic hyperthermia on the programmable viral protein capsid disassembly using (1) elongated nanocomposites of TMV coated heterogeneously with magnetic iron oxide nanoparticles (TMV@IONPs) and (2) spherical nanocomposites of polystyrene (PS) on which we deposited presynthesized IONPs and TMV via layer-by-layer self-assembly (PS@IONPs/TMV). Notably, we found that the extent of the disassembly of the protein cages is contingent upon the specific absorption rate (SAR) of the magnetic nanoparticles, that is, the heating efficiency, and the relative position of the protein cage within the nanocomposite concerning the heating sources. This implies that the spatial arrangement of components within the hybrid nanostructure has a significant impact on the disassembly process. Understanding and optimizing this relationship will contribute to the critical spatiotemporal control for targeted drug and gene delivery using protein cages.

Improving the thermal-mechanical performance of bio-treated backfill materials by addition of magnetic iron oxide nanoparticles (nano-Fe3O4)

The thermal conductivity of backfill materials directly affects the heat transfer efficiency between energy geo-structures and the surrounding stratum. Microbially induced carbonate precipitation (MICP) possesses great potential for improving the thermal conductivity of backfill materials. Magnetic iron oxide nanoparticles (i.e., nano-Fe3O4) have been proven to enhance bacterial biochemical activity by altering the permeability of bacterial biofilms, thus potentially improving the MICP process. It was supposed to enhance the thermal conductivity of backfill materials, allowing for applying energy geo-structures in arid environments. In this study, MICP in a solution environment was conducted to analyze bacterial urease activity and morphology of precipitation at varying nano-Fe3O4 contents. Additionally, sand columns treated with MICP and different nano-Fe3O4 contents were performed to obtain the thermal conductivity and unconfined compressive strength (UCS) through the transient plane source (TPS) method and uniaxial compression (UC) experiment. The mineral type, precipitation morphology, and microstructure were identified using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The mechanism of the effect of nano-Fe3O4 on bacterial urease activity and thermal-mechanical behaviors was also discussed. The results indicated that the nano-Fe3O4 could enhance bacterial urease activity and promote vaterite precipitation in the solution environment. Conversely, when applied to MICP-treated sand, nano-Fe3O4 could facilitate calcite formation. Increasing the nano-Fe3O4 content showed a positive correlation with increased thermal conductivity and UCS. Specifically, the optimal values of thermal conductivity and UCS increased by 2.42 times and 2.39 times, respectively, compared to MICP-treated specimens without nano-Fe3O4. Microstructure analysis revealed that calcite precipitation at the particle contact served a dual function: cementing particles, thereby improving the mechanical strength and simultaneously acting as a "thermal bridge" to enhance the thermal conductivity. Furthermore, this study provides a new perspective on utilizing magnetized bacteria to reinforce specific locations within rocks and soils in the presence of an external magnetic field.

Synthesis of Gd-DTPA Carborane-Containing Compound and Its Immobilization on Iron Oxide Nanoparticles for Potential Application in Neutron Capture Therapy.

Cancer is one of the leading causes of global mortality, and its incidence is increasing annually. Neutron capture therapy (NCT) is a unique anticancer modality capable of selectively eliminating tumor cells within normal tissues. The development of accelerator-based, clinically mountable neutron sources has stimulated a worldwide search for new, more effective compounds for NCT. We synthesized magnetic iron oxide nanoparticles (NPs) that concurrently incorporate boron and gadolinium, potentially enhancing the effectiveness of NCT. These magnetic nanoparticles underwent sequential modifications through silane polycondensation and allylamine graft polymerization, enabling the creation of functional amino groups on their surface. Characterization was performed using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray (EDX), dynamic light scattering (DLS), thermal gravimetric analysis (TGA), and transmission electron microscopy (TEM). ICP-AES measurements indicated that boron (B) content in the NPs reached 3.56 ppm/mg, while gadolinium (Gd) averaged 0.26 ppm/mg. Gadolinium desorption was observed within 4 h, with a peak rate of 61.74%. The biocompatibility of the NPs was confirmed through their relatively low cytotoxicity and sufficient cellular tolerability. Using NPs at non-toxic concentrations, we obtained B accumulation of up to 5.724 × 1010 atoms per cell, sufficient for successful NCT. Although limited by its content in the NP composition, the Gd amount may also contribute to NCT along with its diagnostic properties. Further development of the NPs is ongoing, focusing on increasing the boron and gadolinium content and creating active tumor targeting.

NEW MAGNETIC COLLOIDAL SYSTEMS BASED ON BIOMIMETIC POLYCOMPLEXES

This paper presents new colloidal systems that have prospects for use as carriers of medicinal compounds and are polymer complexes based on polyacrylic acid molecules of various molecular weights and biogenic polyamine, additionally modi ed with magnetic iron oxide nanoparticles. The main physicochemical characteristics of the resulting polycomplexes were determined. The possibility of incorporating the drug compound doxorubicin into polycomplexes was demonstrated and the magnetic properties of polycomplexes functionalized with magnetic iron oxide nanoparticles were studied.

Impacts of designed vanillic acid-polymer-magnetic iron oxide nanocomposite on breast cancer cells

The engineered nano-vehicle was constructed using magnetic iron oxide nanoparticles (MIONs) and chitosan (CTS) to stabilize anticancer agent vanillic acid (VNA) which was loaded on CTS-coated MIONs nanocarrier, and more importantly, to achieve sustained VNA release and subsequent proper anticancer activity. The new thermally stable VNA-CTS- MIONs nanocomposite was spherical with a middle diameter of 6 nm and had a high drug loading of about 11.8 %. The MIONs and resulting nanocomposite were composed of pure magnetite and therefore, were superparamagnetic with saturation magnetizations of 53.3 and 45.7 emu.g−1, respectively. The release profiles of VNA from VNA-CTS-MIONs nanocomposite in different pH values were sustained and showed controlled pH-responsive delivery of the loaded VNA with 89 % and 74 % percentage release within 2354 and 4046 min at pH 5 and 7.4, respectively, as well as were in accordance with the pseudo-second-order model. The VNA-CTS-MIONs nanocomposite treatment at diverse concentrations remarkably decreased the viability and promoted ROS accumulation and apoptosis in the MDA-MB-231 breast cancer cells. Hence, it can be a propitious candidate for the management of breast cancer in the future.

Biomass-derived carbon heterostructure composites modified with magnetic iron oxide for excellent EMW-absorbing materials

With the gradual spread of satellite navigation, broadcasting, and communication technologies, the problem of electromagnetic pollution in C- and Ku-band has increased. Electromagnetic wave (EMW) absorbing materials can effectively mitigate this problem. Here, we report the design of a biomass carbon heterostructure for the absorption of EMWs. This design takes advantage of the natural fiber mesh structure of the loofah and the voids, veins, and basal tissues surrounding the fibers. The material is then carbonized to create a radar antenna-like structure of fibers and nanosheets. This improves the material's conductive loss. In addition, modification with magnetic iron oxide in loofah sponges improves the impedance matching of the materials, enhances the magnetic loss, and increases the heterogeneous interface. We found that the maximum effective absorption frequency range of the prepared EMW-absorbing materials is 3.80 GHz, which is mainly concentrated in the C-band and Ku-band, and its maximum RLminvalue is −59.20 dB. The material's ability to absorb EMWs was also verified by simulating the radar cross section (RCS). In conclusion, this work develops a green and efficient composite material for absorbing EMWs and provides new design ideas for the development of EMW-absorbing materials.

Within-city spatial variations in PM2.5 magnetite nanoparticles and brain cancer incidence in Toronto and Montreal, Canada.

Magnetite nanoparticles are small, strongly magnetic iron oxide particles which are produced during high-temperature combustion and friction processes and form part of the outdoor air pollution mixture. These particles can translocate to the brain and have been found in human brain tissue. In this study, we estimated associations between within-city spatial variations in concentrations of magnetite nanoparticles in outdoor fine particulate matter (PM2.5) and brain cancer incidence. We performed a cohort study of 1.29 million participants in four cycles of the Canadian Census Health and Environment Cohort in Montreal and Toronto, Canada who were followed for malignant brain tumour (glioma) incidence. As a proxy for magnetite nanoparticle content, we measured the susceptibility of anhysteretic remanent magnetization (χARM) in PM2.5 samples (N = 124 in Montreal, N = 110 in Toronto), and values were assigned to residential locations. Stratified Cox proportional hazards models were used to estimate hazard ratios (per IQR change in volume-normalized χARM). ARM was not associated with brain tumour incidence (HR = 0.998, 95% CI 0.988, 1.009) after adjusting for relevant potential confounders. Although we found no evidence of an important relationship between within-city spatial variations in airborne magnetite nanoparticles and brain tumour incidence, further research is needed to evaluate this understudied exposure, and other measures of exposure to magnetite nanoparticles should be considered.

Magnetic Iron Oxide Nanoparticles Coated by Coumarin-Bound Copolymer for Enhanced Magneto- and Photothermal Heating and Luminescent Thermometry.

In this work, we report on the synthesis and investigation of new hybrid multifunctional iron oxide nanoparticles (IONPs) coated by coumarin-bound copolymer, which combine magneto- or photothermal heating with luminescent thermometry. A series of amphiphilic block copolymers, including Coum-C11-PPhOx27-PMOx59 and Coum-C11-PButOx8-PMOx42 bearing luminescent and photodimerizable coumarin moiety, as well as coumarin-free PPhOx27-PMOx57, were evaluated for their utility as luminescent thermometers and for encapsulating spherical 26 nm IONPs. The obtained IONP@Coum-C11-PPhOx27-PMOx59 nano-objects are perfectly dispersible in water and able to provide macroscopic heating remotely triggered by an alternating current magnetic field (AMF) with a specific absorption rate (SAR) value of 240 W.g-1 or laser irradiation with a photothermal conversion efficiency of η = 68%. On the other hand, they exhibit temperature-dependent emission of coumarin offering the function of luminescent thermometer, which operates in the visible region between 20 °C and 60 °C in water displaying a maximal relative thermal sensitivity (Sr) of 1.53%·°C-1 at 60 °C.