Search Results (2,460)

In plant tissues, nanoparticles can stimulate the production of reactive oxygen species (ROS), which, in excess, cause cellular toxicity by damaging membranes, chloroplasts, and DNA. However, they can also activate antioxidant mechanisms, aiding metabolic recovery under oxidative stress. In agriculture, iron oxide (nFe) nanoparticles stand out for their gradual release of the nutrient, preventing leaching and increasing productivity. This study aims to investigate whether iron oxide nanoparticles are effective alternatives for overcoming iron deficiencies, mitigating oxidative stress and restoring metabolic functions, while maintaining photosynthesis. The high H₂O₂ concentration observed in nFe 500 mg L⁻¹ (nFe 500) suggests that Fe, after being transported by the nanoparticles to the leaves, may have acted as a cofactor for antioxidant enzymes involved in H₂O₂ decomposition, reducing malondialdehyde concentration (MDA). Maintaining low oxidative stress suggests that H₂O₂ may function not only as a stress indicator but also as a signaling molecule in intracellular processes. nFe 500 suggests the ability of plants to utilize released Fe²⁺/Fe³⁺, restoring photosynthetic function in iron-deficient plants. Full article

Breast cancer remains a leading cause of cancer-related mortality worldwide, necessitating innovative therapeutic approaches. This scoping review summarizes experimental evidence on the anticancer activity of snake venom and its bioactive components against breast cancer, drawing from a variety of in vitro and in vivo studies. Aimed at critically evaluating the therapeutic potential and underlying mechanisms, this review consolidates findings on venoms from multiple snake species, including both crude preparations and purified proteins or peptides, revealing a diversity of mechanisms of action. Reported effects include induction of apoptosis, generation of reactive oxygen species, disruption of cell membrane integrity, inhibition of cell proliferation and metastasis, and modulation of oncogenic signaling pathways. In vivo findings further indicate tumor growth inhibition and, in some cases, enhanced efficacy when venom-based agents are combined with nanoparticle delivery systems or conventional anticancer drugs. However, a significant proportion of evidence is limited to in vitro studies, with substantial heterogeneity in venom sources, extraction methods, dosages, and cancer models, which constrains generalizability. There is also a lack of systematic data on long-term toxicity, immunogenicity, off-target effects, pharmacokinetics, and formulation challenges. Taken together, these findings highlight snake venom-derived compounds as promising multi-targeted anticancer agents but underscore the urgent need for standardized formulations, rigorous preclinical safety assessments, and translational research to bridge the gap to clinical application. Future investigations should aim to isolate novel venom-derived compounds, refine delivery strategies, and undertake rigorous preclinical safety and pharmacokinetic studies—ultimately moving toward early-phase clinical evaluation to bridge the translational gap and assess the therapeutic potential of these agents. Full article

Background/Objectives: Triple-negative breast cancer (TNBC) exhibits pronounced biological heterogeneity, aggressive behavior, and a high risk of recurrence and metastasis. The conventional treatments for TNBC have notable limitations: surgical resection may leave residual tumor cells; chemotherapy (CT) frequently induces systemic toxicity and drug resistance; and radiotherapy damages surrounding organs and compromises the patients’ immune function. Methods: Herein, we designed a carrier-free nanodrug delivery system composed of self-assembled Curcumin nanoparticles (NPs) coated with a tannic acid (TA)/Fe(III) network (denoted as CUR@TA-Fe(III) NPs). We systematically evaluated the in vitro cytotoxicity and photothermal–ferroptosis synergistic therapeutic efficacy of CUR@TA-Fe(III) NPs in 4T1 breast cancer cells, as well as the in vivo antitumor activity using 4T1 tumor-bearing mouse models. Results: CUR@TA-Fe(III) NPs had high drug loading efficiency (LE) of 27.99%, good dispersion stability, and photothermal properties. Curcumin could inhibit the growth of 4T1 cancer cells, while TA-Fe(III) efficiently converted light energy into heat upon exposure to near-infrared (NIR) light, leading to direct thermal ablation of 4T1 cells. Additionally, TA-Fe(III) could supply Fe(II) via TA, increase intracellular Fe(II) content, and generate reactive oxygen species (ROS) through the Fenton reaction, in turn inducing lipid peroxidation (LPO), a decrease in mitochondrial membrane potential (MMP), and glutathione depletion, eventually triggering ferroptosis. Conclusions: This treatment strategy, which integrates CT, PTT, and ferroptosis, is expected to overcome the limitations of traditional single-treatment methods and provide a more effective method for the treatment of TNBC. Full article

The oxidative dehydrogenation of propane (ODHP) catalyzed by oxygen offers several advantages, including resistance to carbon deposition and low energy consumption. However, achieving high propylene selectivity at industrially relevant conversions remains challenging, as existing catalysts typically require temperatures exceeding 500 °C, promoting over-oxidation to CO_x. In this study, we developed a NiO nanoparticle-decorated graphitic carbon nitride catalyst (NiO@CN-600) via thermal polymerization–oxidation for photo-thermal synergistic ODHP. At 430 °C, thermal catalysis achieved a propane conversion of 14%. Remarkably, introducing light irradiation boosted conversion to 24%, a 10% increase. Further experimental results reveal that the photo-thermal synergistic catalysis can be described by the following mechanism: initial thermal energy provides sufficient activation energy, enabling the reaction to overcome the energy barrier and proceed smoothly. Simultaneously, the introduction of light energy enhances the activity of lattice oxygen, making it more likely to detach from the lattice and form oxygen vacancies, which in turn boosts the efficiency of the oxidation reaction on the catalyst surface. Full article

Pathogenic bacterial infections pose serious health risks, underscoring the need for timely treatments. Manganese dioxide (MnO₂) nanoparticles (NPs) have attracted considerable attention owing to their outstanding chemical stability, favorable biocompatibility, high reactivity, and catalytic ability to decompose hydrogen peroxide, making them promising antibacterial agents. A clear understanding of their antibacterial mechanisms is essential for evaluating their therapeutic potential in clinical settings. In this study, MnO₂ NPs were synthesized by reacting potassium permanganate (KMnO₄) with poly(allylamine hydrochloride) (PAH), ensuring complete conversion to MnO₂ NPs. The resulting NPs were characterized for their physicochemical properties, and their antibacterial activity against E. coli and S. aureus was evaluated using growth curve assays and reactive oxygen species (ROS) quantification. Results indicated the killing efficiency of MnO₂ NPs increased with exposure time and concentration, reflecting high susceptibility of both bacterial strains. Scanning electron microscopy (SEM) analysis revealed that the interaction between MnO₂ NPs and bacterial cells caused significant disruption of cell wall integrity. This study provides a valuable platform for evaluating MnO₂ nanoparticles as antibacterial agents and for exploring their mechanisms in medical applications. Full article

Bismuth-based oxyfluorides (BiO_xF_3−2x) have recently emerged as promising photocatalysts due to their unique electronic structures and tunable physicochemical properties. This review provides a comprehensive overview of these materials, focusing on their crystal structures, band gap characteristics, and photocatalytic performance. Particular attention is given to BiOF, Bi₇O₅F₁₁, and β-BiO_xF_3−2x, highlighting the influence of fluorine’s high electronegativity and internal electric fields on charge separation and light absorption. The potential of Aurivillius-type oxyfluorides is also discussed. Structural modifications, such as the introduction of oxygen vacancies, morphology control, and metal/non-metal doping, are examined for their effects on photocatalytic efficiency. Furthermore, various synthesis techniques and heterojunction engineering strategies involving semiconductors, carbon-based materials, and metal nanoparticles are explored to improve light harvesting and reduce charge recombination. Applications in pollutant degradation and CO₂ photoconversion are reviewed, demonstrating the versatility of these materials. Despite their promise, the challenges associated with phase identification and composition control are also emphasized, underlining the need for rigorous structural characterization. Future directions for optimizing the photocatalytic activity of bismuth-based oxyfluorides are outlined, focusing on strategies to enhance their performance. Full article

Current Pt-based methane combustion catalysts require high noble metal loadings (≥1 wt%) and exhibit insufficient low-temperature activity. To address this, we developed a 0.5 wt% Pt catalyst supported by sulfate-modified Fe-Ce-TiO₂ (denoted 0.5Pt/CFT-TS) via sol–gel synthesis using titanium oxysulfate (TiOSO₄) precursor. Control catalysts prepared with TiCl₄, titanium butoxide, or commercial TiO₂ showed inferior performance. Structural characterization revealed that the TiOSO₄ derived carrier possesses a mesoporous framework (156.2 m²/g surface area, 8.1 nm pore size) with residual SO₄²⁻ inducing strong Brønsted acidity (1.23 mmol/g NH₃ adsorption) and elevated Ce³⁺ concentration (49.45%). These properties synergistically enhanced oxygen vacancy density (51.16% O_α fraction) and stabilized sub-nm Pt nanoparticles. The resulting Pt⁰-Fe³⁺/Ce⁴⁺-Oᵥ interface facilitated dynamic redox cycling (Fe³⁺ + Ce⁴⁺ + 0.5O²⁻ ⇌ Fe²⁺ + Ce³⁺ + 0.5Oᵥ + 0.25O₂), lowering oxygen vacancy regeneration barriers (H₂-TPR peak reduced by 45 °C) and decreasing methane activation energy to 46.77 kJ/mol. This catalyst achieved T₉₀ = 163 °C and complete conversion at 450 °C under industrial conditions (1% CH₄/4% O₂, GHSV = 30,000 h⁻¹), establishing a novel design strategy for low-Pt combustion catalysts. Full article

The development of effective catalysts for the oxygen reduction reaction (ORR) is crucial for improving the performance of fuel cells. Efficient carbon-supported Pt-Co nanocatalysts were successfully prepared by a generic two-step method: (i) electroless deposition of a Co-P coating on Vulcan XC72R carbon powder and (ii) subsequent spontaneous partial galvanic replacement of Co by Pt, upon immersion of the Co/C precursor in a chloroplatinate solution. The prepared Pt-Co particles (of a core-shell structure) are dispersed on a Vulcan XC-72 support, forming agglomerates made of nanoparticles smaller than 10 nm. The composition and surface morphology of the samples were characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS) as well as transmission electron microscopy (TEM). The crystal structures of the Co-P/C precursor and Pt-Co/C catalyst were investigated by X-ray diffraction (XRD). XPS analysis was performed to study the chemical state of the surface layers of the precursor and catalyst. The electrochemical behavior of the Pt-Co/C composites was evaluated by cyclic voltammetry (CV). Linear sweep voltammetry (LSV) experiments were used to assess the catalytic activity towards the ORR and compared with that of a commercial Pt/C catalyst. The Pt-Co/C catalysts exhibit mass-specific and surface-specific activities (of j_m = 133 mA mg⁻¹ and j_esa = 0.661 mA cm⁻², respectively) at a typical overpotential value of 380 mV (+0.85 V vs. RHE); these are superior to those of similar electrodes made of a commercial Pt/C catalyst (j_m = 50.6 mA mg⁻¹; j_esa = 0.165 mA cm⁻²). The beneficial effect of even small (<1% wt.%) quantities of Co in the catalyst on Pt ORR activity may be attributed to an optimum catalyst composition and particle size resulting from the proposed preparation method. Full article

In this study, we report, for the first time, the tribo-catalytic degradation of methyl orange (MO) using Cu/Al₂O₃ nanoparticles under mechanical stirring conditions. The hybrid catalyst was synthesized via a wet impregnation method and characterized through different techniques, confirming structural integrity and compositional uniformity. When subjected to friction generated by a PTFE-coated magnetic stir bar, Cu/Al₂O₃ nanoparticles exhibited high tribo-catalytic activity, achieving up to 95% MO degradation within 10 h under dark conditions. The observed activity surpasses that of alumina alone and is attributed to the synergistic effects between copper and alumina, facilitating charge separation and enhancing reactive oxygen species (ROS) formation. Tribo-catalytic efficiency was further influenced by stirring speed and contact area, confirming the key role of mechanical friction. Reusability tests demonstrated stable performance over five cycles, highlighting the material’s durability and potential for practical environmental remediation applications. Full article

This study characterized extracellular vesicles (EVs) isolated from medicinal herb Centella asiatica tissue culture and investigated their therapeutic properties using in vitro assays and a ultraviolet (UV)-induced damage mouse model. EVs were isolated from C. asiatica tissue culture and characterized by nanoparticle tracking analysis, and cytotoxicity, antioxidant, anti-melanin, and anti-inflammation properties were evaluated by in vitro assays. C. asiatica EVs were found to contain high levels of polyphenols and mitigate hydrogen peroxide-induced intracellular reactive oxygen species (ROS). The EVs were further able to reduce intracellular melanin content and tyrosinase activity. They exhibited anti-inflammatory effects by downregulating the expression of pro-inflammatory genes, COX2, as well as nitric oxide production. In the UV-induced photodamage mouse model, gels with or without EVs were applied to the UV-damaged site, skin appearance was observed daily, and skin histopathology was analyzed on day 7. In mice with UV-induced skin damage, the daily application of C. asiatica EV gel reduced skin epidermis thickness and inflammation compared to UV-only or blank gel at seven days after UV irradiation. The beneficial effects of C. asiatica EVs on skin quality warrant further studies as promising agents in skin care applications. Full article

We present a novel approach for the synthesis of crystalline zinc oxide (ZnO) nanopowders based on the direct interaction of high-power microwave radiation with a zinc wire in atmospheric air. The process utilizes a localized microwave-induced plasma to rapidly vaporize the metal, followed by oxidation and condensation, resulting in the deposition of ZnO nanostructures on glass substrates. Plasma diagnostics confirmed the generation of a plasma in local thermodynamic equilibrium (LTE), characterized by high electron temperatures. Optical emission spectroscopy highlighted atomic species such as ZnI, ZnII, OI, OII, and NI, as well as molecular species including OH, N₂ and O₂. The spectral fingerprint of N₂ molecules reveals the presence of high energy electrons, while the persistent occurrence of OI and OII emission lines throughout the plasma spectrum reveals that ZnO formation is mainly driven by the continuous dissociation of molecular oxygen. High crystallinity and chemical purity of the synthesized ZnO nanoparticles were confirmed through SEM, TEM, XRD, FTIR, and EDX characterization. The resulting nanorods exhibit a rod-like morphology, with diameters ranging from 12 nm to 63 nm and lengths between 58 nm and 354 nm. This low-cost, high-yield method offers a scalable and efficient route for metal oxide nanomaterial fabrication via direct metal–microwave coupling, providing a promising alternative to conventional physical and chemical synthesis techniques. Full article

Se rods decorated with SnO₂ nanoparticles have been synthesized via a facile hydrothermal approach to bridge the gap between ultraviolet-only and visible-only photocatalysis and to enhance reactive oxygen species generation under visible illumination. Structural and morphological analyses using X-ray diffraction and scanning electron microscopy with energy dispersive spectroscopy have confirmed the coexistence of cassiterite SnO₂ particles intimately interfaced with trigonal selenium rods. Diffuse-reflectance spectroscopy revealed a long absorption tail extending into the 400–550 nm range. Under 450 nm sample illumination, the composite produced singlet oxygen in higher yields than either bare SnO₂ or Se, as evidenced by the indocyanine green assay. The system alone does not produce free radicals, as shown by the terephthalic acid test; however, the addition of rhodamine B acts as an effective sensitizer, enabling hydroxyl radical generation. Photodegradation tests using rhodamine B have shown that the SnO₂–Se system outperforms both its single components, Se and SnO₂, as a catalyst. The synergistic interplay underscores the potential of SnO₂–Se heterostructures in photochemical applications under visible light. Full article

Healthcare-associated infections (HAIs) represent one of the most persistent challenges in modern healthcare delivery, affecting millions of patients worldwide and imposing substantial clinical and economic burdens on healthcare systems. The emergence of antimicrobial resistance (AMR) has further complicated infection management, creating an urgent need for innovative therapeutic and preventive strategies. Current strategies for combating AMR in hospital settings encompass comprehensive infection prevention and control measures, antimicrobial stewardship programs, enhanced environmental cleaning protocols and innovative surface modification technologies. Nanotechnology has emerged as a valuable approach to address the limitations of conventional antimicrobial strategies. Various nanomaterial categories offer innovative platforms for developing novel treatment strategies and for providing advantages including reduced toxicity through lower dosage requirements, diminished resistance development potential, and enhanced antibacterial effects through combined action mechanisms. Particularly, metal-based nanoparticles and their oxides demonstrate exceptional antimicrobial properties through multiple mechanisms including membrane damage, protein binding and reactive oxygen species generation. This comprehensive review examines the current landscape of hospital-acquired infections, the growing threat of antimicrobial resistance, and the promising role of nanotechnology-based solutions, with particular emphasis on silver nanoparticles as innovative tool for HAI control in clinical settings. Recent advances in nanotechnology-enabled antimicrobial coatings are assessed along with their clinical translation in hospital settings, identifying key barriers concerning material durability, safety profiles, and regulatory pathways. Full article

Surface-enhanced Raman Scattering (SERS) enables ultrasensitive detection but is often hindered by biocompatibility and sustainability concerns due to its reliance on noble metal substrates. To overcome these limitations, we develop a semiconductor-based SERS platform utilizing ultrathin tungsten trioxide (WO₃) nanofilms synthesized via a facile annealing process on fluorine-doped tin oxide (FTO). This system achieves an impressive Raman enhancement factor of 1.36 × 10⁶, enabling ultrasensitive detection of rhodamine 6G (R6G) and methylene blue (MB) at ultralow concentrations, surpassing conventional metal-based SERS platforms. It is further suggested that this is a substrate that can be easily coupled to other metals. An application for the detection of adenine molecules is realized through layered WO₃-Au NPs composites, where embedded gold nanoparticles act as plasma “hot spots” to amplify the sensitivity. Density functional theory (DFT) calculations and band structure analysis confirm that synergistic interface charge transfer and naturally formed oxygen vacancies enhance performance. By combining semiconductor compatibility with other metal amplification, this WO₃-based SERS platform offers a sustainable and high-performance alternative to conventional substrates, paving the way for environmentally friendly and scalable Raman sensing technologies. Full article

This work investigated the oxidation in an atmosphere of N₂O of different surface areas of single nickel nanoparticles deposited on highly oriented pyrolytic graphite (HOPG). Using scanning tunneling microscopy and spectroscopy, it was shown that oxide formation begins at the top of the nanoparticle, while the periphery is resistant to oxidation. The active site of oxygen incorporation is a vibrationally excited group of nickel atoms, and the gap between them is the place where an oxygen adatom penetrates. The characteristic time of vibrational relaxation of the active site is 10⁻⁹–10⁻⁷ s. The reason for the oxidation resistance is the deformation of the nanoparticle atomic lattice near the Ni-HOPG interface. A relative compression of the nanoparticle atomic lattice ξ = 0.4–0.8% was shown to be enough for such an effect to manifest. Such compression increases the activation energy for oxygen incorporation by 6–12 kJ/mol, resulting in inhibition of oxide growth at the periphery of the nanoparticle. In fact, in this work, oxygen adatoms served as probes, and their incorporation between nickel atoms allowed the measurement of the nanoparticle’s lattice parameters at different distances from the Ni–HOPG interface. The developed theoretical framework not only accounts for the observed oxidation behavior but also offers a potential pathway to estimate charge transfer and local work functions for deposited nickel catalysts. Full article