Search Results (113)

Background: Minimally invasive hyperthermia and regenerative therapies require materials that deliver precise, localized heat without compromising biocompatibility. Most conventional polymers are thermally insulating and challenging to control in vivo, motivating this review. Objectives: We aimed to (i) examine the use of thermally enhanced biopolymers in hyperthermia-based therapies, (ii) appraise evidence from clinical and preclinical studies, (iii) identify and classify principal applications in regenerative medicine. Methods: A PRISMA-guided systematic review (2020–2025) with predefined inclusion/exclusion criteria was conducted and complemented by a bibliometric analysis using VOSviewer for mapping and visualization. Results: Modifying biopolymers—via functionalization with photothermal or magnetic nanoagents (Au; Fe₂O₃/Fe₃O₄/CoFe₂O₄; CuS; Ag; MXenes, e.g., Nb₂C), crosslinking strategies, and hybrid formulations—significantly increased thermal conductivity, enabling localized hyperthermia and controlled drug release. In vitro and in vivo studies showed that europium-doped iron oxide nanoparticles embedded in chitosan generated heat efficiently while sparing healthy tissues, underscoring the need to balance biocompatibility and thermal performance. Hydrogel systems enriched with carbon nanomaterials (graphene, carbon nanotubes) and matrices such as GelMA, PNIPAM, hyaluronic acid, and PLA/PLGA demonstrated tissue compatibility and effective thermal behavior; graphene was compatible with neural tissue without inducing inflammation. Conclusions: Thermally conductive biopolymers show growing potential for oncology and regenerative medicine. The evidence supports further academic and interdisciplinary research to optimize safety, performance, and translational pathways. Full article

This study addresses the challenge of low-temperature synthesis of the high-performance L1₀ Fe-Pt intermetallic phase, which is critical for applications in ultra-high-density data storage and advanced magnetic devices. We demonstrate that the choice of iron precursor is a decisive factor in directing the phase composition and thermal evolution of Fe-Pt nanostructures, ultimately determining their suitability as functional composite materials. Fe-Pt systems were synthesized from aqueous solutions using platinum(IV) chloric acid (H₂PtCl₆) with either iron(III) ammonium sulfate (NH₄Fe(SO₄)₂) or iron(II) sulfate (FeSO₄). Comprehensive characterization using X-ray diffraction and high-resolution transmission electron microscopy revealed distinct composite formations. The iron(III) precursor yielded homogeneous, thermally stable nanocomposites: as-synthesized nanoparticles formed a Pt-based FCC solid solution (~5 nm), which upon annealing at 500 °C transformed into a biphasic nanocomposite of FCC solid solution and an L1₂ Fe₂₁Pt₇₉ intermetallic phase with minimal grain growth (~7 nm). In stark contrast, the system derived from iron(II) sulfate resulted in a heterogeneous composite of 4 nm Pt nanoparticles, an FCC solid solution, and discrete 1–3 nm Fe nanoparticles with L1₂-ordered FePt₃ domains. Annealing this heterogeneous mixture caused phase segregation, forming significantly coarsened Pt-rich crystals (~30 nm) that were approximately 4–6 times larger than the crystallites in the annealed homogeneous composite, with negligible Fe incorporation. Our findings establish that precursor chemistry dictates the initial nanocomposite architecture, which in turn controls the pathway and success of low-temperature intermetallic phase formation. This work provides a crucial design principle for fabricating tailored Fe-Pt composite nanomaterials, moving beyond simple alloys to engineered multiphase systems for practical application. Full article

Electromagnetic heating (EMH) using microwaves has emerged as a promising enhanced oil recovery (EOR) technique, particularly for heavy crude oils where conventional thermal methods encounter technical and environmental challenges. However, its large-scale implementation remains limited due to incomplete understanding of its energy transfer mechanisms. This study proposes an experimental–numerical approach integrating magnetic graphene oxide nanoparticles (Fe₃O₄@GO) with microwave heating to enhance energy absorption near the wellbore. The nanomaterial was synthesized via a modified Hummer’s method followed by in situ magnetite precipitation and studied through multiple material characterization techniques showing uniform 80 nm particles with superparamagnetic behavior—ideal for EMH applications. Nine experiments were conducted on sand–heavy-oil–water systems with nanoparticle concentrations up to 500 ppm using a laboratory microwave heating prototype. A simulation model was then developed in CMG-STARS for history matching to estimate energy absorption as a function of saturation and nanoparticle concentration. Experiments reached temperatures up to 240 °C, with 653 MJ of effective heat transferred to the target zone over 55 h, as estimated from the input heat required in the simulator for history matching. The results confirm that magnetic graphene oxide nanoparticles enhance thermal efficiency and heat distribution in microwave-assisted EOR. Full article

Nosocomial infections caused by Candida albicans pose serious challenges to healthcare systems due to their persistence on medical surfaces and resistance to conventional disinfectants. This study evaluates antifungal properties of SnO₂ doped with silver and cuprite nanoparticles and WO₃ thin films, as well as cobalt (CoFe₂O₄) and cobalt–nickel (Co_0.5Ni₀.₅Fe₂O₄) ferrite nanoparticles, activated by ultraviolet C (UVC) radiation, direct electric current (up to 100 V), and magnetic fields. SnO₂ films were synthesized by Spray Pyrolysis and WO₃ by Sputtering deposition, Ferrites nanoparticles by sol–gel, while metallic nanoparticles were synthetized via chemical reduction. Characterization consisted mainly of SEM, TEM, and XRD, and their antimicrobial activity was tested against C. albicans. WO₃ films achieved 86.2% fungal inhibition after 5 min of UVC exposure. SnO₂ films doped with nanoparticles reached 100% inhibition when combined with UVC and 100 V. Ferrite nanoparticles alone showed moderate activity (21.9%–40.4%) but exhibited strong surface adhesion to fungal cells, indicating potential for magnetically guided antifungal therapies. These results demonstrate the feasibility of using multifunctional nanomaterials for rapid, non-chemical disinfection. The materials are low-cost, scalable, and adaptable to hospital settings, making them promising candidates for reducing healthcare-associated fungal infections through advanced surface sterilization technologies. Full article

Background/Objectives: Magnetic nanoparticles, particularly iron oxide-based materials, such as magnetite (Fe₃O₄), have gained significant attention as contrast agents in medical imaging This study aimsto syntheze and characterize Fe₃O₄-based core–shell nanostructures, including Fe₃O₄@TiO₂ and Fe₃O₄@SiO₂, and to evaluate their potential as tunable contrast agents for diagnostic imaging. Methods: Fe₃O₄, Fe₃O₄@TiO₂, and Fe₃O₄@SiO₂ nanoparticles were synthesized via co-precipitation at varying temperatures from iron salt precursors. Fourier transform infrared spectroscopy (FTIR) was used to confirm the presence of Fe–O bonds, while X-ray diffraction (XRD) was employed to determine the crystalline phases and estimate average crystallite sizes. Morphological analysis and particle size distribution were assessed by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) and transmission electron microscopy (TEM). Magnetic properties were investigated using vibrating sample magnetometry (VSM). Results: FTIR spectra exhibited characteristic Fe–O vibrations at 543 cm⁻¹ and 555 cm⁻¹, indicating the formation of magnetite. XRD patterns confirmed a dominant cubic magnetite phase, with the presence of rutile TiO₂ and stishovite SiO₂ in the coated samples. The average crystallite sizes ranged from 24 to 95 nm. SEM and TEM analyses revealed particle sizes between 5 and 150 nm with well-defined core–shell morphologies. VSM measurements showed saturation magnetization (Ms) values ranging from 40 to 70 emu/g, depending on the synthesis temperature and shell composition. The highest Ms value was obtained for uncoated Fe₃O₄ synthesized at 94 °C. Conclusions: The synthesized Fe₃O₄-based core–shell nanomaterials exhibit desirable structural, morphological, and magnetic properties for use as contrast agents. Their tunable magnetic response and nanoscale dimensions make them promising candidates for advanced diagnostic imaging applications. Full article

Glycated hemoglobin (HbA1c) is an important biomarker applied for the diagnosis, evaluation, and management of diabetes; therefore, its accurate determination is crucial. In this study, an innovative nanoplatform was developed, integrating carbon nanotubes (CNTs) with enhanced hydrophilicity achieved through cyclodextrin (CD) functionalization, and combined with gold nanoparticles (AuNPs) electrochemically deposited onto a screen-printed carbon electrode. The nanomaterials significantly improved the analytical performance of the sensor due to their increased surface area and high electrical conductivity. This nanoplatform was employed as a substrate for the covalent attachment of thiolated ferrocene-labeled HbA1c specific aptamer through Au-S binding. The electrochemical signal of ferrocene was covered by a stronger oxidation peak of Fe²⁺ from the HbA1c structure, leading to the elaboration of a nanostructured aptasensor capable of the direct detection of HbA1c. The electrochemical aptasensor presented a very wide linear range (0.688–11.5%), an acceptable limit of detection (0.098%), and good selectivity and stability, being successfully applied on real samples. This miniaturized, simple, easy-to-use, and fast-responding aptasensor, requiring only a small sample volume, can be considered as a promising candidate for the efficient on-site determination of HbA1c. Full article

This study addresses the critical challenge of maintaining drilling fluid performance and wellbore stability in high-pressure, high-temperature (HPHT) environments, where conventional water-based drilling fluids often fail. This research investigates whether the integration of single- and dual-nanomaterial systems into base fluids can significantly enhance rheological behavior and shale inhibition potential. Using secondary experimental datasets and computational modeling, five nanomaterials—SiO₂, Al₂O₃, TiO₂, Fe₂O₃, and Fe₃O₄—were evaluated individually and in dual combinations with polymers. Key performance metrics, including plastic viscosity, fluid loss, and shale recovery, were analyzed and fitted to the Herschel–Bulkley rheological model. The results showed that single-nanomaterial systems modestly improved viscosity and fluid loss control, with SiO₂ and Fe₂O₃ offering the best standalone performance. Dual systems—particularly SiO₂–Al₂O₃ and Fe₃O₄–polymer combinations—demonstrated superior rheological performance with reduced viscosity (down to 19 cP), minimized fluid loss (<4 mL/30 min), and enhanced shale recovery (>90%). These improvements suggest synergistic effects between nanomaterials, supporting their use in designing advanced, thermally stable drilling fluids for extreme HPHT wells. Full article

Cadmium (Cd) mobilization in paddy soils during redox fluctuations poses significant risks to rice safety. This study investigated the efficacy of nano-calcium carbonate (NCC), nano-hydroxyapatite (NHAP), and their composite (C+P) in immobilizing Cd under simulated flooding–drainage cycles. Soil treatments (0.5% and 1.0% w/w) were subjected to 40 day anaerobic and 20 day aerobic incubation. The results demonstrated that NCC and C+P elevated the soil pH by 1.35–1.39 and 0.72–1.01 units during the anaerobic and aerobic phases, respectively. These amendments suppressed Fe(II) and Mn(II) release by 41–75%, correlating with reduced Cd bioavailability. While nanomaterials minimally influenced Cd speciation during flooding, aerobic conditions triggered a marked shift: residual Cd fractions increased by 80.8–116.4% under NCC, driven by CdCO₃ precipitation and phosphate complexation. Cd release rates decreased by 53.6–66.8% in NCC and C+P treatments during oxidation. Microbial analysis revealed diminished bacterial diversity but enriched Firmicutes (up to 58.9%), which positively correlated with pH and residual Cd. Redundancy analysis identified pH and Fe/Mn dynamics as key regulators of the microbial community structure. NCC emerged as the most effective amendment. This study highlights the potential of NCC-based strategies for mitigating Cd risks in acidic paddy soils, particularly during post-flooding drainage. Full article

FeCo alloys, renowned for their exceptional magnetic properties, such as high saturation magnetization and elevated Curie temperatures, hold significant potential for various technological applications. This study combines density-functional theory (DFT) and Monte Carlo (MC) simulations to investigate the magnetic properties of FeCo alloys and nanoclusters. DFT-derived exchange coupling constants ($J_{ij}$) and magnetic anisotropy ($K_i$) along with machine learning (ML) predicted spin vectors ($S_i$) serve as inputs for the Monte Carlo framework, enabling a detailed exploration of magnetic coercivity ($H_c$) across different compositions and temperatures. The simulations reveal an optimal Fe concentration, particularly around Fe_0.65Co_0.35, where magnetic coercivity reaches its peak, aligning with experimental trends. A similar simulation procedure was conducted for a Fe₅₈Co₃₂ nanocluster at 300 K and 500 K, demonstrating magnetic behavior comparable to bulk materials. This integrative computational approach provides a powerful tool for simulating and understanding the magnetic properties of alloys and nanomaterials, thus aiding in the design of advanced magnetic materials. Full article

The development of heterostructures incorporating photocatalysts optimized for visible-light activity represents a major breakthrough in the field of environmental remediation research, offering innovative and sustainable solutions for environmental purification. This study explores the photocatalytic capabilities of a SnFe₂O₄/g-C₃N₄ heterojunction nanocomposite, successfully synthesized from graphitic carbon nitride (g-C₃N₄) and tin ferrate (SnFe₂O₄) and applied to the degradation of the cationic dye brilliant cresyl blue (BCB) in an aqueous solution. These two components are particularly attractive due to their low cost and ease of fabrication. Various characterization techniques, including XRD, FTIR, SEM, and TEM, were used to confirm the successful integration of SnFe₂O₄ and g-C₃N₄ phases in the synthesized catalysts. The photocatalytic and photo-Fenton-like activity of the heterojunction composites was evaluated by the degradation of brilliant cresyl blue under visible LED illumination. Compared to the pure components SnFe₂O₄ and g-C₃N₄, the SnFe₂O₄/g-C₃N₄ nanocomposite demonstrated a superior photocatalytic performance. Furthermore, the photo-Fenton-like performance of the composites is much higher than the photocatalytic performances. The significant improvement in photo-Fenton activity is attributed to the synergistic effect between SnFe₂O₄ and g-C₃N₄, as well as the efficient separation of photoexcited electron/hole pairs. The recyclability of the SnFe₂O₄/g-C₃N₄ composite toward BCB photo-Fenton like degradation was also shown. This study aimed to assess the modeling and optimization of photo-Fenton-like removal BCB using the SnFe₂O₄/g-C₃N₄ nanomaterial. The main parameters (photocatalyst dose, initial dye concentration, H₂O₂ volume, and reaction time) affecting this system were modeled by two approaches: a response surface methodology (RSM) based on a Box–Behnken design and artificial neural network (ANN). A comparison was made between the predictive accuracy of RSM for brilliant cresyl blue (BCB) removal and that of the artificial neural network (ANN) approach. Both methodologies provided satisfactory and comparable predictions, achieving R² values of 0.97 for RSM and 0.99 for ANN. Full article

The selective detection of propane gas molecules using semiconductor gas sensors has always been a challenge within research. In this study, we successfully synthesized a γ-Fe₂O₃ nanomaterial with a selective catalytic effect on propane and loaded it onto a ZnO sensing material to construct a double-layer microsensor, which showed good sensing response characteristics in the detection of the refrigerant R290 (which is mainly propane). In addition, we also prepared a series of iron oxides, including nanomaterials such as α-Fe₂O₃, Fe₃O₄, and FeO, as well as γ-Fe₂O₃ materials with different specific surface areas obtained at various processing temperatures, and we carried out gas sensing research on R290. The results show that the γ-Fe₂O₃ material has a better sensitivity to R290, and the γ-Fe₂O₃ material calcined at 200 °C shows the best performance. Our results can provide a theoretical basis for the design and optimization of semiconductor gas sensors for alkane detection. Full article

Diaryldithiocarbamate complexes, [Fe(S₂CNAr₂)₃], have been prepared and their structure, reactivity, and thermal degradation to afford iron sulfide nanomaterials have been investigated. The addition of three equivalents of LiS₂CNAr₂ to FeCl₂·4H₂O in water-air affords dark red [Fe(S₂CNAr₂)₃] in high yields. All show magnetic measurements consistent with a predominantly high-spin electronic arrangement at room temperature. The molecular structure of [Fe{S₂C(N-p-MeOC₆H₄)₂}₃] reveals the expected distorted octahedral geometry, but Fe-S distances are more consistent with a low-spin electronic configuration, likely a result of the low temperature (120 K) of the data collection. The thermal stability of [Fe{S₂C(N-p-MeC₆H₄)₂}₃] has been investigated. TGA shows that it begins to decompose at a significantly lower temperature (ca. 160 °C) than previously observed for [Fe(S₂CNEt₂)₃], and this is further lowered (to ca. 100 °C) in oleylamine. The decomposition of [Fe{S₂C(N-p-MeC₆H₄)₂}₃] in oleylamine, via either a heat-up or hot injection process, affords nanoparticles of Fe₃S₄ (greigite), while in contrast, dry heating at 450 °C affords FeS (troilite) as large agglomerates. Full article

A magnetic shell-structured nano-catalyst was prepared by self-polymerization of dopamine wrapped by ferric oxide as the carrier, which was loaded with palladium nanoparticles (Pd/PDA@Fe₃O₄). The presence of magnetic Fe₃O₄ made it easy for nanoscale palladium particles to recover and prevent the loss of palladium nanoparticles that is unavoidable in traditional usage and preparation procedures. The catalyst was characterized by X-ray diffraction, fourier transform infrared spectroscopy, scanning electron microscopy, thermal weight loss analysis, Raman spectroscopy, X-ray photo-electron spectroscopy, and magnetic properties analysis. The catalytic performance of the prepared catalyst was investigated taking 4-nitrophenol (10 mg/L) and rhodamine B (15 mg/L) as the target pollutants. The results showed that under the conditions of 35 °C, pH = 7 and a catalyst dosage of 3 mg, the catalytic reduction efficiency of 4-nitrophenol, rhodamine B, and the mixture of them all can reach 99%. The catalytic efficiency of Pd/PDA@Fe₃O₄ remained above 90% after being used 10 times. The shell structure of Fe₃O₄ made it possible and easy to recover and recycle the nanoscale palladium, which was a real problem in the usage of nano-catalysts. At the same time, the problem of separation and recovery of palladium nano-catalyst is solved by magnetism, which provides research ideas for the recycling and utilization of nano-materials. Full article

In order to improve the charge transfer properties and reduce the recombination of photogenerated carriers, an Fe₂O₃/C₃N₄ heterojunction was constructed to increase the built-in field. The grain boundary of the Fe₂O₃/C₃N₄ nanocomposite was filled with Cu, Au, Pt, and Pd nanoparticles using in situ synthesis. The nanometal-modified heterostructures showed good absorption in the visible and near-infrared (NIR) regions. The photocurrent responses to the light sources with wavelengths of 405, 532, 650, 780, 808, 980, and 1064 nm were investigated using Au electrodes. The results indicated that the nanocomposite exhibits photocurrent switching behaviour towards the visible-light and NIR regions. Interestingly, the reversible photocurrent response phenomenon (transition from negative to positive photoconductivity) was observed before and after passivation of the grain boundary defects of the Fe₂O₃/C₃N₄ heterojunction with metal nanoparticles. The physical mechanisms involved were discussed. The Cu nanomaterials played donor effects in the interfacial tailoring of the Fe₂O₃/C₃N₄ heterojunction since Cu nanoparticles possess a high concentration of free electrons. It was shown that defects in the nanocomposites play an important role in the photoelectric behaviour and that modulation of the defects not only enhances photocurrent acquisition but also determines the polarity of the photocurrent. This study provides useful guidance not only for microstructure modulation and interdisciplinary applications of the materials themselves but also for the study of light–matter interactions. Full article

A novel magnetic nanomaterial with Fe₃O₄ as the core, PS-DVB as the shell layer, and the surface modified with C18 (C18−PS−DVB−Fe₃O₄) had been synthesized by seeded emulsion polymerization. C18−PS−DVB−Fe₃O₄ retains the advantages of the chemical stability, large porosity, and uniform morphology of organic polymers and has the magnetic properties of Fe₃O₄. A simple, flexible, and efficient magnetic dispersive solid phase extraction (Mag-dSPE) method for the extraction of preservatives, sweeteners, and colorants in river water was established. C18−PS−DVB−Fe₃O₄ was used as an adsorbent for Mag-dSPE and was coupled with high-performance liquid chromatography (HPLC) to detect 11 food additives: acesulfame, amaranth, benzoic acid, tartrazine, saccharin sodium, sorbic acid, dehydroacetic acid, sunset yellow, allura red, brilliant blue, and erythrosine. Under the optimum extraction conditions, combined with ChromCoreTMAQC18 (5 μm, 4.6 × 250 mm), 20 mmol/L ammonium acetate aqueous solution and methanol were used as mobile phases, and the detection wavelengths were 240 nm and 410 nm. The limits of detection (LODs) of 11 food additives were 0.6–3.1 μg/L with satisfactory recoveries ranging from 86.53% to 106.32%. And the material could be reused for five cycles without much sacrifice of extraction efficiency. The proposed method has been used to determine food additives in river water samples, and results demonstrate the applicability of the proposed C18−PS−DVB−Fe₃O₄ Mag-dSPE coupled with the HPLC method to environment monitoring analysis. Full article