Decomposition Of Peroxide Research Articles

Platinum nanozyme co-loaded reactive oxygen species-responsive prodrug integrated with dissolvable microneedle for chemotherapy and photodynamic therapy of melanoma

Melanoma, the most aggressive form of skin cancer, is characterized by an increasing incidence rate. However, conventional treatment methods such as surgery, chemotherapy, radiotherapy, and immunotherapy have limitations that hinder their widespread application. In this study, we aim to develop a platinum nanozyme (PtNP) co-loaded reactive oxygen species (ROS)-responsive prodrug integrated with dissolvable microneedle for chemotherapy and photodynamic therapy of melanoma. The utilization of microneedle can significantly enhance the efficiency of transdermal drug delivery while improving treatment efficacy and minimizing toxic side effects. The nanodrug system incorporates a prodrug composed of chemotherapeutic agent, photosensitizer, and ROS-responsive chemical bond. Upon laser irradiation, it generates ROS for effective photodynamic therapy while precisely controlling the release behavior of camptothecin (CPT) within the prodrug formulation. Furthermore, PtNP in the nanodrug exhibits nanozyme-like activity by catalyzing the decomposition of hydrogen peroxide into oxygen to overcome hypoxia-related challenges and enhance the effectiveness of photodynamic therapy. The integration of the nanodrug complex with dissolvable microneedle presents a synergistic approach for the combined delivery of chemotherapy and photodynamic therapy to melanoma patients, offering novel strategies and avenues for clinical treatment.

Nanosensors Monitor Intracellular GSH Depletion: GSH Triggers Cu(II) for Tumor Imaging and Inhibition.

Glutathione (GSH) is the primary antioxidant in cells, and GSH consumption will break the redox balance in cells. Based on this, a method that uses high concentrations of GSH in the tumor microenvironment to trigger the redox reaction of Cu(II) to generate copper nanoprobes with fluorescence and tumor growth inhibition properties is proposed. The nanoprobe mainly exists in the form of Cu(I) and catalyzes the decomposition of hydrogen peroxide into hydroxyl radicals. At the same time, a simple and controllable carbon micro-nano electrode is used to construct a single-cell sensing platform, which enable the detection of glutathione content in single living cells after Cu(II) treatment, providing an excellent example for detecting single-cell biomolecules.

Carbon Quantum Dots/Cu2O Photocatalyst for Room Temperature Selective Oxidation of Benzyl Alcohol.

The luminescence properties and excellent carrier transfer ability of carbon quantum dots (CQDs) have attracted much attention in the field of photocatalysis. In this work, we loaded the CQDs on the surface of Cu2O to enhance the visible-light property of Cu2O. Furthermore, the composite was used for selective oxidation of benzyl alcohol to benzaldehyde. The composite catalyst achieved high selectivity (90%) for benzaldehyde at room temperature, leveraging its visible-light-induced electron transfer properties and its photocatalytic activity for hydrogen peroxide decomposition. ·OH was shown to be the main reactive oxygen species in the selective oxidation reaction of benzyl alcohol. The formation of heterostructures of CQDs/Cu2O promoted charge carrier separation and provided a fast channel for photoinduced electron transfer. This novel material exhibited enhanced levels of activity and stability for selective oxidation of benzyl alcohol. Potential applications of carbon quantum dot composites in conventional alcohol oxidation reactions are shown.

Biomedicial therapeutic potential of copper tannic acid coordination nanosheet with multiple catalytic properties

The utilization of nanomaterials in disease treatment has become a prominent area of research in the medical field. Nanocarrier materials endowed with catalytic and biological enzyme properties have exhibited promising prospects for applications in treating chronic inflammatory diseases, including cancer and diabetes. In this study, we have successfully synthesized a versatile CuTA nanosheets with a cost-effective approach, making it suitable for various pathological models. The CuTA nanosheets exhibit remarkable characteristics, including catalyzing the Fenton reaction for peroxide decomposition and accelerating the release of nitric oxide (NO) through the catalysis of endothelial nitric oxide synthase (eNOS), both of which are dependent on the concentration of the CuTA nanosheets. Furthermore, at a concentration of 2 mg/mL, the CuTA nanosheets achieved a removal rate of free radicals at 63.7%. When exposed to 808 nm near-infrared light, the temperature rose from 8 °C to 42 °C within 10 min. Additionally, at a concentration of 50 µg/mL, the inhibition rates of CuTA nanosheets on Escherichia coli and Staphylococcus aureus reached 98.3% and 96.1%, respectively. These unique characteristics make it highly suitable for effective applications in various fields, including biomedical, drug delivery, and photothermal therapy.

Explosion incidents associated with comprehensive studies on methyl ethyl ketone peroxide under thermal decomposition: A review

AbstractThis review gathered and discussed the available results on the thermal hazards, thermal kinetics, decomposition mechanism, autocatalytic behavior, thermal explosion, deflagration ability, and incompatibility hazards associated with the thermal decomposition of methyl ethyl ketone peroxide (MEKPO). The present review constructed a diagram showing all activation energy Ea and log A values for the thermal decomposition of MEKPO. Some disagreement exists in the values of Ea and log A (unit: s−1 M1−n) derived from differential scanning calorimetry; thus, more extensive studies must be conducted to resolve disputes. Nearly no literature exists on the thermal explosion and deflagration ability of MEKPO, and the reactions of MEKPO with incompatible contaminants remain unclear. Concerning the complex decomposition mechanism of MEKPO, experimental determination and identifications of intermediates have not been obtained. Available technology must be improved to enable the collection of accurate data on thermal hazards, thermal kinetics, decomposition mechanisms, explosion and deflagration phenomena, autocatalytic behavior, and incompatibility. This review has integrated an up‐to‐date summary of the most recent approaches and offers perspectives regarding future research. These current findings can serve as a reference for completing subsequent experimental investigations, theoretical studies, and designs of inherently safer measures for producing or handling MEKPO.

Catalytically promoted green fuel with hydrogen peroxide: Effect of hypergolic combustion on atomization and flow characteristics using impinging jets

This study explores the jet impingement of a catalytically promoted hypergolic green fuel with High Test Peroxide (HTP). Experimental investigations were conducted using simultaneous high-speed visible, infrared and backlight imaging. Two major aspects were investigated. First, a study exploring the potential of decoupling the combustion phenomenon through the utilization of the fuel without a catalyst as a simulant, enabling a comparative analysis of the atomization process with the authentic hypergolic pair undergoing combustion. A Reynolds versus Weber numbers diagram was obtained for jets with equal momentum in the steady-state flow regime, and a novel breakup mode was observed. The named Reactive Foamy Segregation mode was found as a two phenomenological regime, where a reacting foam exists together with a segregation stream. An analysis of the liquid film velocity formed by impinging jets indicated that the hypergolic pair exhibited significantly lower speeds and corroborates with the introduced breakup mode. Second, an analysis about the transient and steady-state jet flow effects, revealing the existence of separate planes for the reacting foam and plumes, regions with different oxidizer to fuel ratios. This natural effect was intensified by the force generated from the exothermic reaction of hydrogen peroxide decomposition. Notably, the central region of the sheet exhibited the lowest temperature, indicating that the liquid-phase mixture and propellants’ residence time were insufficiently effective in decomposing the peroxide. These findings contribute to a deeper understanding of the complex fluid dynamics involved in catalytically promoted hypergolic reactions applied in liquid rocket engines.

Increase of OH radical yields due to the decomposition of hydrogen peroxide by gold nanoparticles under X-ray irradiation.

We elucidate the decomposition mechanism of hydrogen peroxide, which is formed by water radiolysis, by gold nanoparticles (GNPs) under X-ray irradiation. The variations in yields of hydrogen peroxide generated in the presence of GNPs are evaluated using the Ghormley technique. The increase of yields of OH radicals has been quantified using Ampliflu® Red solutions. Almost all hydrogen peroxide generated by irradiation of <25 Gy is decomposed by GNPs, while the yield of OH radicals increases by 1.6 times. The amount of OH radicals thus obtained is almost equivalent to that of the decomposed hydrogen peroxide. The decomposition of hydrogen peroxide is an essential reaction to produce additional OH radicals efficiently in the vicinity of GNPs.

Fenton Reaction in vivo and in vitro. Possibilities and Limitations.

The review considers the problem of hydrogen peroxide decomposition and hydroxyl radical formation in the presence of iron in vivo and in vitro. Analysis of the literature data allows us to conclude that, under physiological conditions, transport of iron, carried out with the help of carrier proteins, minimizes the possibility of appearance of free iron ions in cytoplasm of the cell. Under pathological conditions, when the process of transferring an iron ion from a donor protein to an acceptor protein can be disrupted due to modifications of the carrier proteins, iron ions can enter cytosol. However, at pH values close to neutral, which is typical for cytosol, iron ions are converted into water-insoluble hydroxides. This makes it impossible to decompose hydrogen peroxide according to the mechanism of the classical Fenton reaction. A similar situation is observed in vitro, since buffers with pH close to neutral are used to simulate free radical oxidation. At the same time, iron hydroxides are able to catalyze decomposition of hydrogen peroxide with formation of a hydroxyl radical. Decomposition of hydrogen peroxide with iron hydroxides is called Fenton-like reaction. Studying the features of Fenton-like reaction in biological systems is the subject of future research.

The novelty of silver extraction by leaching in acetic acid with hydrogen peroxide as an organic alternative lixiviant for cyanide

In this article, the dissolution kinetics of pure metallic silver in acetic acid with a hydrogen peroxide solution were carried out. The effects of stirring speed, acetic acid concentration, hydrogen peroxide concentration, and temperature were examined. The results show that increasing the stirring speed decomposes the hydrogen peroxide and negatively affects the dissolution rate of silver. In addition, an acetic acid concentration in the range of 0.25–1 M has a positive effect and a negative effect in the range of 1–3 M. A hydrogen peroxide concentration in the range of 0.5–2 M has a significantly positive effect on the dissolution rate, while it has a negative effect in the range of 2–3 M. The temperature in the range of 61.5–70 °C has a negative effect due to the decomposition of hydrogen peroxide. The shrinking core model was applied to all parameters to obtain the dissolution kinetics. The dissolution process of silver was controlled by the surface reaction-controlled shrinking core model, i.e. 1-(1-X)1/3 = kst, with an activation energy of 28.80 kJ/mol.

A dual-mode sensing platform for electron spin resonance and UV-vis detection of alkaline phosphatase based on Cu-based metal-organic frameworks.

Alkaline phosphatase (ALP) is an indispensable hydrolase in living organisms and the abnormality of ALP activity is correlated with a variety of diseases. Exploring ALP activity is important for clinical diagnosis and biomedical research to understand its physiological function. In this study, a dual-mode biosensing platform was constructed based on Cu-based metal-organic frameworks (Cu-MOFs) for electron spin resonance (ESR) and ultraviolet-visible (UV-vis) sensing of ALP. Cu-MOFs, as peroxidase mimics, catalyzed the decomposition of hydrogen peroxide (H2O2) and the generation of reactive oxygen species (ROS) which could oxidize ABTS into ABTS˙+ with good ESR and UV-vis signals. Pyrophosphate ions (PPi) with high affinity to Cu2+ in Cu-MOFs could suppress the peroxidase-like activity of Cu-MOFs, and ALP could hydrolyze PPi, resulting in the recovery of Cu-MOF catalytic activity. Thus, a quantitative dual-mode method for detection of ALP activity was established with good linearity in the range of 0-42 U L-1 and limits of detection as low as 0.386 and 0.523 U L-1 respectively for ESR and UV-vis detection. Benefiting from its high sensitivity and excellent selectivity, this method was applied for ALP detection in human serum and satisfactory recoveries were achieved. The off-on dual-mode sensing platform is more reliable than the single-mode sensor and shows merits like simple operation and cost-friendliness, making it have great potential in the diagnosis of ALP-related diseases.

Design of poly(N-isopropylacrylamide) coated MnO2 nanoparticles for thermally regulated catalytic decomposition of H2O2

We report the synthesis of thermoresponsive poly(N-isopropylacrylamide) coated manganese dioxide nanoparticles for the catalytic decomposition of hydrogen peroxide (H2O2), with the goal of developing a temperature-controlled catalytic system.

Clean treatment and reuse of cotton mercerizing waste alkali resources using multi-stage evaporation technology

Mercerizing is a key procedure for enhancing the performance of cotton fabrics. However, it has the disadvantages of large wastewater discharge, high alkalinity and difficult treatment. To achieve the recycling of NaOH from mercerizing wastewater, a cleaner recovery system based on multi-stage evaporation was proposed. The properties of different alkali liquors and their applications in bleaching and mercerizing were compared and analyzed. The cooperative enterprises have also evaluated the carbon emission reduction and economic benefits of the recommended system. The results show that the NaOH concentration was increased by 2 times after the mercerizing waste alkali was treated. Compared to NaOH, the whiteness of cotton fabric bleached with recycled alkali decreased by 6.0% ∼ 8.7%, mainly due to the ineffective decomposition of hydrogen peroxide. The cotton fabric mercerized with recovered alkali exhibits a crystallinity of 52.7%, a barium value of 220, and a capillary effect of 8.5 cm/30 min. These values meet the production requirements of the textile industry. The recovery system can recover 57.68 t of mercerization waste liquid, save 9.88 t of 32% NaOH solution, 45 t of water and 3.92 t of 98% sulfuric acid per day. Compared to the conventional process, the system not only reduces energy consumption and pollutant discharge at their source, but also improves the utilization rate of water resources and chemicals.

The Kornblum DeLaMare rearrangement in natural product synthesis: 25 years of innovation.

Covering: 1998 up to the end of 2023Since its initial disclosure in 1951, the Kornblum DeLaMare rearrangement has proved an important synthetic transformation and has been widely adopted as a biomimetic step in natural product synthesis. Utilising the base catalysed decomposition of alkyl peroxides to yield a ketone and alcohol has found use in many syntheses as well as a key strategic step, including the unmasking of furans, as a biomimetic synthetic tool, and the use of the rearrangement to install oxygen enantioselectively. Since ca. 1998, its impact as a synthetic transformation has grown significantly, especially given the frequency of use in natural product syntheses, therefore this 25 year time period will be the focus of the review.

Reaction rate and thermal effects of hydrogen peroxide decomposition in microfluidic chips containing channel-type silver catalysts

A test device for the reaction performance of hydrogen peroxide reaction solution for catalytic decomposition in a microchannel silver catalytic bed.

Micromotor-based electrochemical immunoassays for reliable determination of amyloid-β (1–42) in Alzheimer's diagnosed clinical samples.

Alzheimer's disease (AD), in addition to being the most common cause of dementia, is very difficult to diagnose, with the 42-amino acid form of Aβ (Aβ-42) being one of the main biomarkers used for this purpose. Despite the enormous efforts made in recent years, the technologies available to determine Aβ-42 in human samples require sophisticated instrumentation, present high complexity, are sample and time-consuming, and are costly, highlighting the urgent need not only to develop new tools to overcome these limitations but to provide an early detection and treatment window for AD, which is a top-challenge. In recent years, micromotor (MM) technology has proven to add a new dimension to clinical biosensing, enabling ultrasensitive detections in short times and microscale environments.To this end, here an electrochemical immunoassay based on polypyrrole (PPy)/nickel (Ni)/platinum nanoparticles (PtNPs) MM is proposed in a pioneering manner for the determination of Aβ-42 in left prefrontal cortex brain tissue, cerebrospinal fluid, and plasma samples from patients with AD. MM combines the high binding capacity of their immunorecognition external layer with self-propulsion through the catalytic generation of oxygen bubbles in the internal layer due to decomposition of hydrogen peroxide as fuel, allowing rapid bio-detection (15 min) of Aβ-42 with excellent selectivity and sensitivity (LOD = 0.06 ng/mL). The application of this disruptive technology to the analysis of just 25 μL of the three types of clinical samples provides values concordant with the clinical values reported, thus confirming the potential of the MM approach to assist in the reliable, simple, fast, and affordable diagnosis of AD by determining Aβ-42.

Construction of Manganese-Based Oyster (Crassostrea gigas) Ferritin Nanozyme with Catalase-like Enzyme Activity.

MnO2 is a nanozyme that inhibits the decomposition of hydrogen peroxide (H2O2) into a hydroxyl radical (OH•), thus preventing its conversion into reactive oxygen species (ROS). Oyster ferritin (GF1) is a macromolecular protein that provides uniform size and high stability and serves as an excellent template for the biomineralization of nanozyme. This study presents a unique method in which MnO2 is grown in situ in the GF1 cavity, yielding a structurally stable ferritin-based nanozyme (GF1@Mn). GF1@Mn is demonstrated to be stable at 80 °C and pH 4-8, exhibiting a higher affinity with H2O2 than many other catalases (CAT) with a Michaelis constant (Km) of 25.45 mmol/L. In vitro experiments have demonstrated the potential of GF1@Mn to enhance cell survival by reducing nitric oxide (NO) production while mitigating macrophage damage from ROS. The findings are essential to developing ferritin-based nanozymes and hold great potential for applications in functional food development.

Determining the possibility of using cold plasma for the oxidation of atmospheric nitrogen into nitrogen oxides and the influence of activating substances on the process

The process of oxidation of molecular nitrogen by high-energy oxidants, such as nitric acid vapor, products of the thermolysis of nitric acid, and hydrogen peroxide, in a cold plasma stream was studied. To implement the process of obtaining nitric acid from atmospheric air using reproductive technology (Zakharov's method), the design of a reactor for obtaining nitrogen oxides by direct oxidation of nitrogen in a cold plasma stream is proposed. At the same time, it was proposed to use the effect of obtaining nitrogen oxides in an air mixture with nitric acid vapors (the Karavaev effect) and during the thermal decomposition of hydrogen peroxide with atmospheric nitrogen (the Nagiev effect). The effectiveness of the use of cold plasma for the oxidation of atmospheric nitrogen was established, which is confirmed by the obtained dependences. It is shown that the amount of nitrogen oxides that are formed depends on the efficiency of the formation of a stable flow of OH- radicals in the plasma flow. It was also found that the amount of nitrogen oxides depends on the parameters of the plasma generator, the composition of the liquid used in the burner, and the amount of air supplied. The effect of nitric acid, hydrogen peroxide, and alcohols as activators of atmospheric nitrogen oxidation in a high-energy field was revealed. It was determined that when comparing three activator substances, which are able to form OH- radicals during their decomposition, it is hydrogen peroxide that is the most promising activator substance for carrying out the process of atmospheric nitrogen oxidation in the plasma flow. The amount of nitrogen oxides formed in the cold plasma region is almost independent of the flow rate of the reaction mixture through the reactor and remains almost unchanged in a wide range of changes in flow rates from 30 to 3000 l/h

Tumor Microenvironment Modulating CaCO3 -Based Colloidosomal Microreactors Can Generally Reinforce Cancer Immunotherapy.

Tumor hypoxia and acidity, two general features of solid tumors, are known to have negative effect on cancer immunotherapy by directly causing dysfunction of effector immune cells and promoting suppressive immune cells inside tumors. Herein, a multifunctional colloidosomal microreactor is constructed by encapsulating catalase within calcium carbonate (CaCO3 ) nanoparticle-assembled colloidosomes (abbreviated as CaP CSs) via the classic double emulsion method. The yielded CCaP CSs exhibit well-retained proton-scavenging and hydrogen peroxide decomposition performances and can thus neutralize tumor acidity, attenuate tumor hypoxia, and suppress lactate production upon intratumoral administration. Consequently, CCaP CSs treatment can activate potent antitumor immunity and thus significantly enhance the therapeutic potency of coloaded anti-programmed death-1 (anti-PD-1) antibodies in both murine subcutaneous CT26 and orthotopic 4T1 tumor xenografts. In addition, such CCaP CSs treatment also markedly reinforces the therapeutic potency of epidermal growth factor receptor expressing chimeric antigen receptor T (EGFR-CAR-T) cells toward a human triple-negative breast cancer xenograft by promoting their tumor infiltration and effector cytokine secretion. Therefore, this study highlights that chemical modulation of tumor acidity and hypoxia can collectively reverse tumor immunosuppression and thus significantly potentiate both immune checkpoint blockade and CAR-T cell immunotherapies toward solid tumors.

Geopolymer composite foams reinforced with refractory filler: The effect of curing regime on microstructure, porosity and thermomechanical properties

Porous geopolymers with sustainable dimensional stability at high temperatures represent a noteworthy challenge for the development of thermomechanical, reliable and multifunctional composites. This study reports on the porosity formation of refractory-reinforced geopolymer paste via hydrogen peroxide decomposition. Reinforcing the slurry with ceramic chamotte and cordierite increases the apparent viscosity more than eight times in the interval to 100 s−1 retaining a pseudoplastic behavior. Cordierite particles increase the plastic viscosity at 6 Pa s and yield stress above 28 Pa. Surprisingly, the particulate ceramic filler acts as a porosity-modifier thereby reducing the mesoporosity region. Microstructural and porosity behavior was studied via digital microscopy, SEM, MIP and micro-CT. The wrinkled morphology of ceramics significantly affects the macroporosity formation in the region of 100 μm reaching a total porosity of ∼60 vol%. The presence of large pores in the macro region and the high distribution of interconnected porosity in ceramics-reinforced composite foams resulted in compressive strengths ranging from 2 to 10 MPa. The effect of curing rate on porosity was most evident in the cordierite reinforcement which led to the occurrence of large interconnected pores. Based on thermomechanical analysis, the ceramic-reinforced foams show high dimensional stability with a reduction in total shrinkage to −0.71 % at 850 °C. These results may foster further developments of innovative routes for the synthesis of geopolymer composite foams for widespread technological applications.

Mesoporous Zr@KIT-6 silicas: synthesis, characterization studies and catalytic application in the decomposition of hydrogen peroxide

Mesoporous Zr@KIT-6 silicas: synthesis, characterization studies and catalytic application in the decomposition of hydrogen peroxide