Search Results (2,486)

MnFe₂O₄ magnetic nanoparticles have shown broad application prospects in the field of tumor diagnosis and treatment; however, precise particle size regulation within the 100–200 nm range, as well as the synergistic integration of physical and medical functionalities, remains challenging. As a commonly used method for synthesizing MnFe₂O₄ nanoparticles, the solvothermal method has been proven to enable the regulation of the particle size of products, particularly its ability to utilize the viscosity of solvents as a method for particle size regulation. Therefore, this work investigates the influence of the diethylene glycol (DEG) to ethylene glycol (EG) ratio on particle size regulation in solvothermal synthesis of MnFe₂O₄ nanoparticles, and constructs MnFe₂O₄@PB nanocomposite materials. The results demonstrate that with the DEG ratio increasing from 0 to 80% in a DEG:EG mixed solvent system, the average particle size of MnFe₂O₄ nanoparticles can be reduced from 266 nm to 105 nm. The MPB4.5 sample (MnFe₂O₄:PB molar ratio = 5:4.5 in the MnFe₂O₄@PB nanostructure) exhibits an optimal photothermal heating effect and good photothermal stability, demonstrating potential as a photothermal therapeutic agent. The resultant MnFe₂O₄@PB system provides a strategy for precise particle size regulation and functional integration for photothermal therapy of tumors with magnetic targeting potential. Full article

The contamination of food and beverages with heavy metals, such as Cd, presents significant health risks, underscoring the need for reliable and sensitive analytical methods. This study introduces the development of a rapid, cost-effective, and environmentally friendly method for Cd determination in cachaça, a traditional Brazilian sugarcane spirit. Magnetic nanoparticles (Fe₃O₄) functionalized with tetraethyl orthosilicate are synthesized and employed as adsorbents in a dispersive magnetic solid-phase extraction procedure. The extracted Cd is quantified using flame atomic absorption spectrometry. A full factorial experimental design is used to optimize key parameters, including the sorbent mass, adsorption time, desorption time, and acid concentration. The method demonstrates excellent analytical performance, with a linear calibration range (R² = 0.99), detection limit of 0.0046 mg L⁻¹, and quantification limit of 0.0200 mg L⁻¹. Moreover, validation results show high precision (coefficient of variation < 9.10%) and accuracy (recovery rates between 92.00% and 120.00%). When analyzing commercial cachaça samples, cadmium was detected in all five specimens. Notably, in one sample the cadmium concentration exceeded Brazil’s maximum permissible limit of 0.0200 mg kg⁻¹, underscoring the importance of this work for ensuring food safety. The proposed method offers a sensitive, reproducible, and sustainable approach for analysis of potentially toxic trace metals in alcoholic beverages, reinforcing its potential for routine monitoring and regulatory compliance. Full article

Resource utilization of water treatment residuals (WTRs) has emerged as a significant focus in environmental engineering research. In this study, waste iron sludge from a groundwater de-ironing plant was used as the raw material. Ferric salts were recovered via sulfuric acid leaching and subsequently polymerized into polyferric sulfate (PFS) with varying basicity (B = 0.1–0.4) using the alkalization–aging method. The optimal leaching conditions were determined as a liquid–solid ratio of 10:1, a sulfuric acid concentration of 3 mol·L⁻¹, a reaction temperature of 70 °C, and a reaction time of 30 min, yielding a ferric leaching amount of 0.45 g Fe/g dry sludge. Characterization results revealed that the synthesized PFS exhibited similar ferric polymer species, functional group structures, and polymeric crystal structures to those of commercial PFS (CPFS). Coagulation performance tests demonstrated that at a dosage of 30 mg Fe/L, the prepared PFS achieved turbidity and UV₂₅₄ removal efficiencies of 96.88% and 81.87%, respectively, outperforming CPFS. In domestic wastewater treatment, combining the synthesized PFS with magnetic nanoparticles Fe₃O₄@C yielded a magnetic coagulant that further enhanced the removal of turbidity, chemical oxygen demand (COD), and total phosphorus (TP) to maximum efficiencies of 94.66%, 81.97%, and 98.08%, respectively. This study confirms the technical feasibility and environmental–economic benefits of preparing magnetic PFS coagulants from waste iron sludge for wastewater treatment. Full article

Lilium species produce some of the most commercially valuable ornamental flowers in the world, characterized by their attractiveness and high demand in cut flower markets. However, it is necessary to strengthen the competitiveness of this sector in the global market. Due to strong competition from international producers and an increasingly demanding market regarding quality, shelf life, and sustainability, alternatives are being sought to counteract the use of conventional agrochemicals. The use of nanoparticles has emerged as a promising strategy in ornamental horticulture due to their ability to enhance plant growth, improve stress tolerance, and stimulate physiological processes, ultimately contributing to higher quality and productivity. The hypothesis of this research is that the foliar application of selenium and titanium dioxide nanoparticles during the vegetative growth and flowering stages significantly enhances the growth, development, and flowering of Lilium plants when compared with untreated plants. Therefore, the physiological effects of SeNPs and TiO₂NPs applied via foliar application in two concentrations (SeNPsD1, SeNPsD2, TiNPsD1, and TiNPsD2) were evaluated against absolute control. The treatments were applied in two phenological stages (vegetative and reproductive development), and their effects on vegetative and reproductive variables in Lilium plants were evaluated from 120 to 270 days after sowing. The surface of seeds obtained from SeNPsD1-treated plants was further analyzed via scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS). The results demonstrate that the application of SeNPs generated variable effects depending on the phenological stage. In the vegetative stage (46 DAS), SeNPsD2 increased the number of leaves by 118%, while SeNPsD1 increased the fresh weight of leaves by 110%. Regarding ovaries, the application of SeNPsD2 resulted in a 276% increase in fresh weight and a 230% increase in dry weight, while SeNPsD1 achieved an increase of 164% in fresh weight. Furthermore, at this stage, SeNPsD2 promoted a 223% increase in the number of bulbils, a 240% increase in fresh weight, and a 199% increase in dry weight. In the reproductive stage (69 DAS), SeNPsD1 increased the leaf fresh weight by 1% and yielded a 107% increase in the number of ovaries, in addition to 307% and 328% increases in their fresh and dry weights, respectively. In the same stage, SeNPsD2 increased the fresh ovary weight by 153%, compared with the control. Finally, capsule formation was observed only under the SeNPsD1 treatment. Meanwhile, TiO₂NPs had an effect on the number of buds and the number of open buds: the number of buds increased by 115% with TiNPsD1 (69 DAS) and the number of open buds increased by 104% (46 DAS) with TiNPsD1; in the reproductive stage, the number increased by 115% with TiNPsD1 compared with the control. In the seed capsules of plants treated with selenium nanoparticles (SeNPsD1), although no surface selenium was detected via EDS, elements that had possibly been physiologically redistributed were identified, including iron (Fe), silicon (Si), and aluminum (Al). These findings confirm the hypothesis of this research, demonstrating that the foliar application of SeNPs and TiO₂NPs to Lilium plants during the vegetative and reproductive stages significantly improves their vegetative growth, reproductive development, and floral quality under controlled conditions. This work presents the first comparative evidence regarding the effects of SeNPs and TiO₂NPs on the vegetative and reproductive characteristics of Lilium Sunny Oriental, providing unprecedented information for the use of nanotechnology in ornamental horticulture. The findings confirm the potential use of nanoparticles as agents to optimize the productivity and commercial quality of ornamental flowers in highly competitive markets. Full article

With the rapid evolution of nanotechnology, magnetic iron oxide nanoparticles (MNPs)—primarily Fe₃O₄ and γ-Fe₂O₃—have gained prominence in biomedicine. Their extensive specific surface area, tunable surface functionalities, and intrinsic magnetic characteristics render them highly versatile for diverse clinical applications, including tumor visualization through Magnetic Resonance Imaging (MRI), radiolabeling, targeted radiotherapy, hyperthermia, gene transfer, drug delivery, Magnetic Particle Imaging (MPI), magnetic blood filtration and theranostic strategies. Nevertheless, ensuring the biocompatibility and non-toxicity of these nanostructures remains a fundamental prerequisite for their medical implementation. Hence, it is essential to continuously refine our understanding of MNP-related toxicity and pursue comprehensive research on this front. This article consolidates up-to-date insights into the evaluation of MNPs’ toxicological profiles, emphasizing the influence of physicochemical properties such as morphology, surface modifications, and electrostatic characteristics, along with operational factors like dosage and administration routes. Traditional toxicity testing strategies, including in vitro assays as first-line screening tools, together with standard ex vivo and in vivo models, are discussed. Special attention is given to the emerging role of New Approach Methodologies (NAMs), such as organoid formation, 3D bioprinting, in ovo chicken embryo assays, and image cytometry. These techniques offer ethical, human-relevant, and informative alternatives to animal testing, supporting more predictive and translationally relevant toxicity assessment of MNPs. Taken together, the integration of conventional assays with innovative NAMs, alongside careful consideration of physicochemical and operational factors, is essential to translate the laboratory promise of MNPs into safe and clinically effective nanomedicines. Full article

Designing efficient nanoparticle-enhanced CO₂ capture systems is challenging due to the diversity of nanoparticles, solvent formulations, reactor configurations, and operating conditions. This study presents the first ANN-based meta-analysis framework developed to predict CO₂ absorption enhancement across multiple reactor systems, including batch reactors, packed columns, and membrane contactors. A curated dataset of 312 experimental data points was compiled from literature, and an artificial neural network (ANN) model was trained using six input variables: nanoparticle type, concentration, system configuration, base fluid, pressure, and temperature. The proposed model achieved high predictive accuracy (R² > 0.92; RMSE: 4.2%; MAE: 3.1%) and successfully captured complex nonlinear interactions. Feature importance analysis revealed nanoparticle concentration (28.3%) and system configuration (22.1%) as the most influential factors, with functionalized nanoparticles such as Fe₃O₄@SiO₂-NH₂ showing superior performance. The model further predicted up to 130% enhancement for ZnO in optimized membrane contactors. This AI-driven tool provides quantitative insights and a scalable decision-support framework for designing advanced nanoparticle–solvent systems, reducing experimental workload, and accelerating the development of sustainable CO₂ capture technologies. Full article

Photodynamic therapy (PDT) is a promising, minimally invasive treatment for cervical cancer, but its efficacy is significantly limited by hypoxia—oxygen deficiency in the tumour microenvironment. The aim of this study was to present strategies to counteract hypoxia in PDT using the latest nanotechnologies. Based on a review of the literature available in PubMed/MEDLINE, Scopus, and Web of Science databases, covering the period from January 2024 to March 2025, nine original in vivo studies were identified that investigated the use of nanoparticle-based strategies to overcome hypoxia and enhance the efficacy of PDT in cervical cancer. A variety of approaches to improve tumour oxygenation are described, including the catalytic decomposition of hydrogen peroxide (H₂O₂) with manganese oxide (MnO₂), the use of bimetallic nanozymes (e.g., Au₂Pt), and FeOOH structures and oxygen storage and control systems (e.g., endoperoxides). Strategies to reduce oxygen consumption by cancer cells, such as nitric oxide (NO) release or inhibition of mitochondrial oxidative phosphorylation, are also discussed. The review shows that appropriately designed nanoparticles can effectively counteract hypoxia, enhancing the efficacy of PDT by intensifying reactive oxygen species (ROS) generation and modulating HIF-1α factor expression. The strategies presented here have the potential to significantly improve the efficacy of photodynamic therapy in the treatment of cervical cancer, especially under conditions of limited oxygen availability. Full article

This work presents the synthesis and application of magnetic Fe₃O₄ nanoparticles supported on baobab seed-derived biochar (Fe₃O₄/BSB) for removing Congo red (CR) dye from aqueous solutions through an oxidative process. The biochar support offered a porous structure with a surface area of 85.6 m²/g, facilitating uniform dispersion of Fe₃O₄ nanoparticles and efficient oxidative activity. Fourier-transform infrared (FT–IR) spectroscopy analysis confirmed surface fictionalization after Fe₃O₄ incorporation, while scanning electron microscopy (SEM) images revealed a rough, porous morphology with well-dispersed nanoparticles. Thermogravimetric analysis (TGA) demonstrated enhanced thermal stability, with Fe₃O₄/BSB retaining ~40% of its mass at 600 °C compared to ~15–20% for raw baobab seeds. Batch experiments indicated that operational factors such as pH, nanoparticles dosage, and initial dye concentration significantly affected removal efficiency. Optimal CR removal (94.2%) was achieved at pH 4, attributed to stronger electrostatic interactions, whereas efficiency declined from 94.1% to 82.8% as the initial dye concentration increased from 10 to 80 mg/L. Kinetic studies showed that the pseudo-second-order model accurately described the oxidative degradation process. Reusability tests confirmed good stability, with removal efficiency decreasing only from 92.6% to 80.7% after four consecutive cycles. Overall, Fe₃O₄/BSB proves to be a thermally stable, magnetically recoverable, and sustainable catalyst system for treating dye-contaminated wastewater. Full article

Magnetically separable TiO₂-based composite photocatalysts have gained significant interest in the past two decades; however, the optimization of their synthesis and the stabilization of the magnetic iron oxide within the composite is still an open challenge. The present study investigates the photocatalytic behavior and recyclability of TiO₂-Fe₃O₄ composites, with emphasis on a possible correlation between pollutant degradation efficiency, recyclability, iron oxide stability, and the phase composition of the chosen TiO₂ base. Magnetite nanoparticles were synthesized under varied temperature and alkaline conditions to identify optimal parameters for achieving the desirable magnetic properties. The magnetic nanoparticles were integrated into composite systems with either commercial TiO₂ (Evonik Aeroxide P25 with anatase–rutile mixed phase) or a hydrothermally synthesized anatase TiO₂. The P25-based composite removed 99% paracetamol from aqueous solutions under UV-A irradiation and demonstrated successful recyclability, maintaining 96% paracetamol degradation efficiency after four uses. In contrast, the anatase TiO₂-based magnetic composite exhibited a lower performance (70%) and a significantly hindered recyclability (45% after four cycles). The difference in performance was attributed to variations in the phase composition of the employed TiO₂ in the composites and, consequently, in their charge separation mechanisms. Full article

The solid-state reactions between Fe₂O₃ and molecular sulfur sources could produce FeS nanoparticles efficiently, while the functions of these molecules have been ignored except for the role as sulfur sources. In this work, thioacetamide and thiourea were employed as sulfur sources for the solid-state reactions with Fe₂O₃ to explore their effects on the microstructure and electrochemical performance of the produced FeS. Despite the slight difference in one functional group for two molecules (−CH₃ against −NH₂), thiourea leads to a more complex reaction pathway with FeS₂ as the intermediate phase, while no such an intermediate phase is observed in the reaction with thioacetamide. The former yields FeS of 2D nanoflakes as the final products, compared with the aggregated nanoparticles in reactions with thiourea. As a result, the nanoflakes exhibit a higher discharge capacity with enhanced stability (388.9 mAh∙g⁻¹ vs. 374.7 mAh∙g⁻¹ above 1 V). According to the reaction pathways, the formation of FeS nanoflakes and superior electrochemical performance were addressed, paving a route for the solid-state reactions with molecules to develop high-performance sulfide electrode materials. Full article

Synergizing iron nutrition and rice quality is essential for the development of integrated high-quality rice. In this study, a two-year field experiment was conducted to investigate the influence of ferric oxide nanoparticles (Fe₂O₃ NPs) foliar spraying on rice yield, quality, and iron bioavailability, with spraying water as the control (CK). Our results demonstrate that Fe₂O₃ NPs foliar application increase grain yield by 1.22–3.97% for the improved filled grain rate and 1000-grain weight, essentially attributed to improved net photosynthetic rate and SPAD value after heading. In addition, Fe₂O₃ NPs application achieved a higher rate of brown rice, polished rice, and head rice, and decreased chalkiness grain rate and chalkiness degree. Rice taste value treated with Fe₂O₃ NPs application was notably increased by 2.75–9.43% compared to CK, respectively, which is also reflected in the superior breakdown value (5.85–15.18%) and inferior setback value (12.38–28.19%). Meanwhile, foliar spraying Fe₂O₃ NPs significantly increased the iron content (16.97–58.74% and 26.48–94.01%) and proportion (2.90–5.35% and 13.10–26.44%), while they decreased the molar ratio of phytate to Fe (19.70–33.67% and 31.55–45.77%) in brown rice and polished rice, increasing iron bioavailability. Our findings indicate that Fe₂O₃ NPs can be effectively applied as a foliar fertilizer to enhance rice yield, quality, and iron nutrition. Full article

Endocytic uptake and lysosomal localization are suggested to be the key mechanisms underlying the toxicity of metal oxide nanoparticles (MONPs), with dissolution in the acidic milieu driving the response. In this study, we aimed to investigate if MONPs of varying solubility are similarly sequestered intracellularly, including in lysosomes and the role of the acidic lysosomal milieu on toxicity induced by copper oxide (CuO) nanoparticles (NPs), nickel oxide (NiO) NPs, aluminum oxide (Al₂O₃) NPs, and titanium dioxide (TiO₂) NPs of varying solubility in FE1 lung epithelial cells. Mitsui-7 multi-walled carbon nanotubes (MWCNTs) served as contrasts against particles. Enhanced darkfield hyperspectral imaging (EDF-HSI) with fluorescence microscopy was used to determine their potential association with lysosomes. The v-ATPase inhibitor Bafilomycin A1 (BaFA1) was used to assess the role of lysosomal acidification on toxicity. The results showed co-localization of all MONPs with lysosomes, with insoluble TiO₂ NPs showing the greatest co-localization. However, only acute toxicity induced by soluble CuO NPs was affected by the presence of BaFA1, showing a 14% improvement in relative survival. In addition, all MONPs were found to be associated with large actin aggregates; however, treatment with insoluble TiO₂ NPs, but not soluble CuO NPs, impaired the organization of F-actin and α-tubulin. These results indicate that MONPs are sequestered similarly intracellularly; however, the nature or magnitude of their toxicity is not similarly impacted by it. Future studies involving a broader variety of NPs are needed to fully understand the role of differential sequestration of NPs on cellular toxicity. Full article

Background/Objectives: Peptide-based inorganic nanoparticles (PINPs) have emerged as promising candidates for intracellular delivery due to their unique structural and functional attributes. These hybrid nanostructures combine the high surface area and tunable optical/magnetic properties of metal cores (e.g., Au, Ag, Fe₃O₄) with the biocompatibility, targeting specificity, and responsive behavior of peptides. In particular, peptides with amphipathic or cell-penetrating features could facilitate efficient transport of molecular cargos across cellular membranes while enabling stimulus-responsive drug release in target tissues. Methods: We review key synthesis methods (especially green, peptide-mediated one-pot approaches), functionalization strategies (e.g., thiol-gold bonds, click chemistries), and characterization techniques (TEM, DLS, FTIR, etc.) that underpin PINP design. In addition, we highlight diverse peptide classes (linear, cyclic, amphipathic, self-assembling) and their roles (targeting ligands, capping/stabilizing agents, reducing agents) in constructing multifunctional nanocarriers. Results: The prospects of PINPs are considerable: they enable targeted drug delivery with imaging/theranostic capability, improve drug stability and cellular uptake, and harness peptide programmability for precision nanomedicine. However, challenges such as in vivo stability, immunogenicity, and standardization of evaluation must be addressed. Conclusions: Overall, PINPs represent multifunctional platforms that could significantly advance drug delivery and diagnostic applications in the future. Full article

Purpose: The synthesis of nanoscale particles with antibacterial properties has garnered significant attention in pharmaceutical research, driven by the escalating threat of antibiotic-resistant bacteria. This study investigates the antibacterial efficacy of Zn–Co ferrite nanoparticles against virulent, antibiotic-resistant, and biofilm-forming strains of Escherichia coli. Methods: Three nanoparticle variants—S1 (Zn_0.7Co_0.3Fe₂O₄), S2 (Zn_0.5Co_0.5Fe₂O₄), and S3 (Zn_0.3Co_0.7Fe₂O₄)—were synthesized using the solution combustion method by systematically varying the Zn:Co molar ratio. The Scanning Electron Micrograph, X-ray diffraction analysis, Complementary Fourier-transform infrared, Minimum Inhibitory Concentration, and Minimum Bactericidal Concentration were performed. Results: The SEM spectroscopy study revealed distinct morphological differences as a function of the cobalt substitution level within the spinel ferrite matrix. At the highest level of cobalt substitution (Zn_0.3Co_0.7Fe₂O₄), the microstructure displayed significant irregularities, with enhanced agglomeration and a notably broader particle size distribution. X-ray diffraction analysis confirmed the formation of crystalline structures, with an average crystallite size of 12.65 nm. Complementary Fourier-transform infrared spectroscopy revealed characteristic absorption bands in the 400–600 cm⁻¹ range, indicative of the cubic spinel structure of the ferrite nanoparticles. The higher-frequency band was associated with metal–oxide stretching in the tetrahedral sites, while the lower-frequency band corresponded to stretching in the octahedral sites. The Minimum Inhibitory Concentration and Minimum Bactericidal Concentration assays revealed that Zn–Co ferrite nanoparticles possess potent antibacterial activity against virulent, antibiotic-resistant, and biofilm-forming strains of E. coli. Conclusion: Increasing the molar ratio of Zn to Co enhances the antibacterial activity of the nanoparticles. These findings suggest that Zn–Co ferrite nanoparticles could serve as a promising alternative to conventional antibacterial agents for combating multidrug-resistant pathogenic bacteria in the future. Full article

This work focuses on the sustainable green synthesis of magnetic iron oxide nanoparticles (Fe₃O₄NPs) using bioreductants derived from orange peel extracts for application in the efficient oxygen evolution reactions (OER). The synthesized catalysts were characterized using X-ray diffraction analysis, field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and UV–visible spectroscopy. The Fe₃O₄NPs exhibit a well-defined spherical morphology with a larger Brunauer–Emmett–Teller surface area and a significant electrochemically active surface area. The green synthesis using orange peel extracts leads to an excellent electrocatalytic activity of the apparent spherical Fe₃O₄NPs (diameter of 9.62 ± 0.07 nm), which is explored for OER in an alkaline medium (1.0 M KOH) using linear-sweep and cyclic voltammetry techniques. These nanoparticles achieved a benchmark current density of 10 mA cm⁻² at a low overpotential of 0.3 V versus RHE, along with notable durability and stability. The outstanding OER electrocatalytic activity is attributed to their unique morphology, which offers large surface area and an ideal porous structure that enhances the adsorption and activation of reactive species. Furthermore, structural defects within the nanoparticles facilitate efficient electron transfer and migration of these species, further accelerating the OER process. Full article