ABSTRACT
Fenton and Fenton-like processes, which could produce highly reactive species to degrade organic contaminants, have been widely used in the field of wastewater treatment. Therein, the chemistry of Fenton process including the nature of active oxidants, the complicated reactions involved, and the behind reason for its strongly pH-dependent performance, is the basis for the application of Fenton and Fenton-like processes in wastewater treatment. Nevertheless, the conflicting views still exist about the mechanism of the Fenton process. For instance, reaching a unanimous consensus on the nature of active oxidants (hydroxyl radical or tetravalent iron) in this process remains challenging. This review comprehensively examined the mechanism of the Fenton process including the debate on the nature of active oxidants, reactions involved in the Fenton process, and the behind reason for the pH-dependent degradation of contaminants in the Fenton process. Then, we summarized several strategies that promote the Fe(II)/Fe(III) cycle, reduce the competitive consumption of active oxidants by side reactions, and replace the Fenton reagent, thus improving the performance of the Fenton process. Furthermore, advances for the future were proposed including the demand for the high-accuracy identification of active oxidants and taking advantages of the characteristic of target contaminants during the degradation of contaminants by the Fenton process.
Subject(s)
Hydrogen Peroxide , Iron , Waste Disposal, Fluid , Iron/chemistry , Hydrogen Peroxide/chemistry , Waste Disposal, Fluid/methods , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/analysis , Wastewater/chemistry , Oxidation-Reduction , Hydroxyl Radical/chemistryABSTRACT
AIM: The objective of the present study was to investigate the association between the anatomical characteristics of different tooth groups and the diffusion and bleaching effect of hydrogen peroxide (H2O2). MATERIALS AND METHODS: Computed tomography (CT) images from five patients were used to assess the hard tissue thickness and pulp volume (PV) of four tooth groups: lower (mandibular) incisors (LI), upper (maxillary) incisors (UI), canines (C), and premolars (PM). Additionally, 80 bovine tooth disks were divided into four groups (n = 20) to match the thickness of each tooth group studied. All the specimens were exposed to a 35% H2O2 bleaching gel, with 50 µL applied for 45 min during the first, second, and third sessions. Diffusion was evaluated using the peroxidase enzyme method. Color change analyses (∆E, ∆E00, and ∆WID) were performed after the three application sessions and 7 days after the bleaching treatment using a spectrophotometer. RESULTS: The PM group showed greater thickness and PV, followed by the C, UI, and LI groups (P 0.001). The LI group had six times greater H2O2 diffusion compared with the PM group (P 0.001), while the PM group exhibited a PV nine times larger than the LI group. Furthermore, the LI and UI groups achieved color saturation with one fewer session than the C and PM groups. CONCLUSIONS: Specific tooth groups have anatomical characteristics that interfere with bleaching treatment in terms of the diffusion and whitening effect of H2O2. Furthermore, the diffusion capacity of H2O2 was inversely proportional to the thickness of the tooth groups.
Subject(s)
Hydrogen Peroxide , Tooth Bleaching , Humans , Tooth Bleaching/methods , Animals , Incisor/anatomy & histology , Incisor/diagnostic imaging , Cattle , Tomography, X-Ray Computed/methods , Bicuspid/diagnostic imaging , Bicuspid/anatomy & histology , Tooth Bleaching Agents , Cuspid/diagnostic imaging , Cuspid/anatomy & histology , Dental Pulp/diagnostic imaging , Dental Pulp/anatomy & histology , Dental Pulp/drug effects , Spectrophotometry/methodsABSTRACT
BACKGROUND: This study aimed to explore the effects of the titanium dioxide (TiO2) concentration and particle size in hydrogen peroxide (HP) on tooth bleaching effectiveness and enamel surface properties. METHODS: TiO2 at different concentrations and particle sizes was incorporated into 40% HP gel to form an HP/TiO2 gel. The specimens were randomly divided into 8 groups: C1P20: HP + 1% TiO2 (20 nm); C3P20: HP + 3% TiO2 (20 nm); C5P20: HP + 5% TiO2 (20 nm); C1P100: HP + 1% TiO2 (100 nm); C3P100: HP + 3% TiO2 (100 nm); C5P100: HP + 5% TiO2 (100 nm); C0: HP with LED; and C0-woL: HP without LED. Bleaching was conducted over 2 sessions, each lasting 40 min with a 7-day interval. The color differences (ΔE00), whiteness index for dentistry (WID), surface microhardness, roughness, microstructure, and composition were assessed. RESULTS: The concentration and particle size of TiO2 significantly affected ΔE00 and ΔWID values, with the C1P100 group showing the greatest ΔE00 values and C1P100, C3P100, and C5P100 groups showing the greatest ΔWID values (p < 0.05). No significant changes were observed in surface microhardness, roughness, microstructure or composition (p > 0.05). CONCLUSIONS: Incorporating 1% TiO2 with a particle size of 100 nm into HP constitutes an effective bleaching strategy to achieve desirable outcomes.
Subject(s)
Gels , Hydrogen Peroxide , Surface Properties , Titanium , Tooth Bleaching Agents , Tooth Bleaching , Titanium/chemistry , Tooth Bleaching/methods , Hydrogen Peroxide/therapeutic use , Hydrogen Peroxide/administration & dosage , Humans , Particle Size , Dental Enamel/drug effectsABSTRACT
During photosynthesis, reactive oxygen species (ROS) are formed, including hydrogen peroxide (H2O2) and singlet oxygen (1O2), which have putative roles in signalling, but their involvement in photosynthetic acclimation is unclear. Due to extreme reactivity and a short lifetime, 1O2 signalling occurs via its reaction products, such as oxidised poly-unsaturated fatty acids in thylakoid membranes. The resulting lipid peroxides decay to various aldehydes and reactive electrophile species (RES). Here, we investigated the role of ROS in the signal transduction of high light (HL), focusing on GreenCut2 genes unique to photosynthetic organisms. Using RNA seq. data, the transcriptional responses of Chlamydomonas reinhardtii to 2 h HL were compared with responses under low light to exogenous RES (acrolein; 4-hydroxynonenal), ß-cyclocitral, a ß-carotene oxidation product, as well as Rose Bengal, a 1O2-producing photosensitiser, and H2O2. HL induced significant (p < 0.05) up- and down-regulation of 108 and 23 GreenCut2 genes, respectively. Of all HL up-regulated genes, over half were also up-regulated by RES, including RBCS1 (ribulose bisphosphate carboxylase small subunit), NPQ-related PSBS1 and LHCSR1. Furthermore, 96% of the genes down-regulated by HL were also down-regulated by 1O2 or RES, including CAO1 (chlorophyllide-a oxygnease), MDH2 (NADP-malate dehydrogenase) and PGM4 (phosphoglycerate mutase) for glycolysis. In comparison, only 0-4% of HL-affected GreenCut2 genes were similarly affected by H2O2 or ß-cyclocitral. Overall, 1O2 plays a significant role in signalling during the initial acclimation of C. reinhardtii to HL by up-regulating photo-protection and carbon assimilation and down-regulating specific primary metabolic pathways. Our data support that this pathway involves RES.
Subject(s)
Chlamydomonas reinhardtii , Photosynthesis , Signal Transduction , Singlet Oxygen , Singlet Oxygen/metabolism , Photosynthesis/genetics , Chlamydomonas reinhardtii/genetics , Chlamydomonas reinhardtii/metabolism , Gene Expression Regulation, Plant , Hydrogen Peroxide/metabolism , Light , Reactive Oxygen Species/metabolismABSTRACT
Screen-printed carbon electrodes (SPCE) functionalized with MXene-based three-dimensional nanomaterials are reported for rapid determination of creatinine. Ti3C2TX MXene with in situ reduced AuNPs (MXene@AuNP) were used as a coreactant accelerator for efficient immobilization of enzymes. Creatinine could be oxidized by chitosan-embedded creatinine amidohydrolase, creatine amidinohydrolase, or sarcosine oxidase to generate H2O2, which could be electrochemically detected enhanced by Prussian blue (PB). The enzyme@CS/PB/MXene@AuNP/SPCE detected creatinine within the range 0.03-4.0 mM, with a limit of detection of 0.01 mM, with an average recovery of 96.8-103.7%. This indicates that the proposed biosensor is capable of detecting creatinine in a short amount of time (4 min) within a ± 5% percentage error, in contrast with the standard clinical colorimetric method. With this approach, reproducible and stable electrochemical responses could be achieved for determination of creatinine in serum, urine, or saliva. These results demonstrated its potential for deployment in resource-limited settings for early diagnosis and tracking the progression of chronic kidney disease (CKD).
Subject(s)
Biosensing Techniques , Carbon , Creatinine , Electrochemical Techniques , Electrodes , Ferrocyanides , Gold , Hydrogen Peroxide , Limit of Detection , Metal Nanoparticles , Sarcosine Oxidase , Ureohydrolases , Creatinine/blood , Creatinine/urine , Carbon/chemistry , Humans , Sarcosine Oxidase/chemistry , Gold/chemistry , Biosensing Techniques/methods , Biosensing Techniques/instrumentation , Ferrocyanides/chemistry , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Hydrogen Peroxide/chemistry , Metal Nanoparticles/chemistry , Ureohydrolases/chemistry , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Chitosan/chemistry , Point-of-Care Testing , Amidohydrolases , TitaniumABSTRACT
Using a chemiluminescence reaction between luminol and H2O2 in basic solution, an ultrasensitive electrochemiluminescence (ECL) aptasensor was developed for the determination of tobramycin (TOB), as an aminoglycoside antibiotic. Ti3C2/Ni/Sm-LDH-based nanocomposite effectively catalyzes the oxidation of luminol and decomposition of H2O2, leading to the formation of different reactive oxygen species (ROSs), thus amplifying the ECL signal intensity of luminol, which can be used for the determination of TOB concentration. To evaluate the performance of the electrochemiluminescence aptasensor and synthesized nanocomposite, different methods such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses were performed. The considerable specific area, large number of active sites, and enhanced electron transfer reaction on this nanocomposite led to the development of an ECL aptasensor with high sensitivity and electrocatalytic activity. After optimizing the preparation method and analysis conditions, the aptasensor revealed a wide linear response ranging from 1.0 pM to 1.0 µM with a detection limit of 18 pM, displaying outstanding accuracy, specificity, and response stability. The developed ECL sensor was found to be applicable to the determination of TOB in human serum samples and is anticipated to possess excellent clinical potentials for detecting other antibiotics, as well.
Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , Electrochemical Techniques , Limit of Detection , Luminescent Measurements , Nanocomposites , Tobramycin , Nanocomposites/chemistry , Humans , Electrochemical Techniques/methods , Aptamers, Nucleotide/chemistry , Luminescent Measurements/methods , Biosensing Techniques/methods , Tobramycin/blood , Tobramycin/analysis , Luminol/chemistry , Anti-Bacterial Agents/blood , Anti-Bacterial Agents/analysis , Hydrogen Peroxide/chemistry , Nickel/chemistry , Titanium/chemistryABSTRACT
OBJECTIVE: To compare the color change, the risk and intensity of tooth sensitivity (TS), and gingival irritation (GI) of at-home bleaching applied on the buccal surface only or the buccal and lingual surfaces. MATERIALS AND METHODS: Sixty patients with canines A2 or darker were selected and their superior arches were randomized in two groups: at-home bleaching on the buccal-only or on the buccal and lingual surfaces, with 7.5% hydrogen peroxide, for 1 h daily/2 weeks. The color change was evaluated at baseline, 7, 14 days, and 1 month after bleaching using shade guides scales (ΔSGU) and a spectrophotometer (ΔEAB, ΔE00, and ΔWID). Risk and intensity of TS and GI were recorded daily using visual analogic scale (0-10). Patient satisfaction was evaluated with the orofacial esthetics. Paired t-test, McNemar's, and Wilcoxon signed-rank test were used for data analysis (α = 5%). RESULTS: Neither the color change nor the risk/intensity of TS was statistically different between groups (p > 0.05). Patient satisfaction increased after bleaching for both groups (p < 0.05). CONCLUSION: The addition of one contact surface does not result in an increased whitening degree compared to bleaching applied solely on the buccal surface. CLINICAL SIGNIFICANCE: Understanding the influence of surfaces interacting with the bleaching agent is crucial for comprehending the bleaching mechanism and avoiding unnecessary material expenses. Notably, employing the buccal-only technique is sufficient to achieve the desired efficacy.
Subject(s)
Tooth Bleaching , Humans , Tooth Bleaching/methods , Single-Blind Method , Female , Male , Adult , Hydrogen Peroxide/administration & dosage , Young AdultABSTRACT
Oxidative stress is a hallmark of secondary injury of spinal cord injuries. Controlling oxidative stress is crucial for mitigating secondary injury and promoting functional recovery after spinal cord injuries. Calycosin is an O-methylated isoflavone with antioxidant activity. To evaluate the effect of calycosin on spinal cord neurons under oxidative stress and clarify the molecular mechanism underlying the effect, we tested the neuroprotective activity of calycosin in a primary spinal cord neuron culture model. We found that calycosin protected neurons from H2O2-induced neuronal death in a dose-dependent manner. Further experiments revealed that calycosin decreased H2O2-induced mitochondrial fragmentation and mitochondrial membrane potential loss, and subsequently reduced H2O2-triggered release of mitochondrial cytochrome c into the cytoplasm. In addition, calycosin inhibited H2O2-induced reactive oxygen species generation and activation of NF-κB signaling in spinal cord neurons. Furthermore, the expression of several antioxidant enzymes such as HO-1, NQO1, GCLC, GCLM, TrxR1, and Trx1 was significantly promoted by calycosin. More importantly, we revealed that the Nrf2/Keap1 signal is crucial for the effect of calycosin, because calycosin increased the amount of nuclear Nrf2 while decreasing the amount of cytoplasmic Nrf2. Nrf2 knockdown with siRNA transfection abolished the neuroprotective effect of calycosin. Taken together, this study disclosed a novel mechanism by which calycosin combats oxidative stress. Our study thus sheds light on the potential clinical application of calycosin in SCI treatment.
Subject(s)
Hydrogen Peroxide , Isoflavones , Kelch-Like ECH-Associated Protein 1 , Mitochondria , NF-E2-Related Factor 2 , Neurons , Signal Transduction , Spinal Cord , Isoflavones/pharmacology , NF-E2-Related Factor 2/metabolism , Kelch-Like ECH-Associated Protein 1/metabolism , Animals , Hydrogen Peroxide/pharmacology , Hydrogen Peroxide/toxicity , Spinal Cord/metabolism , Spinal Cord/drug effects , Spinal Cord/pathology , Signal Transduction/drug effects , Neurons/drug effects , Neurons/metabolism , Neurons/pathology , Mitochondria/metabolism , Mitochondria/drug effects , Oxidative Stress/drug effects , Cell Death/drug effects , Rats , Neuroprotective Agents/pharmacologyABSTRACT
The global concern over water pollution caused by contaminants of emerging concern has been the subject of several studies due to the complexity of treatment. Here, the synthesis of a graphene oxide-based magnetic material (GO@Fe3O4) produced according to a modified Hummers' method followed by a hydrothermal reaction was proposed; then, its application as a photocatalyst in clonazepam photo-Fenton degradation was investigated. Several characterization analyses were performed to analyze the structure, functionalization and magnetic properties of the composite. A 23 factorial design was used for the optimization procedure to investigate the effect of [H2O2], GO@Fe3O4 dose and pH on clonazepam degradation. Adsorption experiments demonstrated that GO@Fe3O4 could not adsorb clonazepam. Photo-Fenton kinetics showed that total degradation of clonazepam was achieved within 5 min, and the experimental data were better fitted to the PFO model. A comparative study of clonazepam degradation by different processes highlighted that the heterogeneous photo-Fenton process was more efficient than homogeneous processes. The radical scavenging test showed that O 2 · - was the main active free radical in the degradation reaction, followed by hydroxyl radicals (â¢OH) and holes (h+) in the valence layer; accordingly, a mechanism of degradation was proposed to describe the process.
Subject(s)
Clonazepam , Graphite , Photolysis , Water Pollutants, Chemical , Graphite/chemistry , Clonazepam/chemistry , Water Pollutants, Chemical/chemistry , Hydrogen Peroxide/chemistry , Adsorption , Water Purification/methods , KineticsABSTRACT
BACKGROUND: The unique size, physical and chemical properties, and ultra-high stability of nanozymes have attracted extensive attentions in sensing, but improvement of catalytic activity of the nanozymes is still an urgent issue. Given the ultra-high simulated enzyme activity of metal nanoparticles and the advantage of multi-enzyme catalysis, an Au-decorated MoS2 nanosheets (MoS2/Au NS) integrating the double peroxidase-like (POD) activity is developed. RESULTS: By optimizing and adjusting the density of AuNPs, as well as its morphology and other parameters, a monodisperse and high-density distribution of AuNPs on MoS2 nanosheets was obtained, which can greatly improve the POD-like activity of MoS2/Au NS. Nafion solution was applied to assist the modification of MoS2/Au NS on the electrode surface so as to improved its stability. An electrochemical H2O2 detection platform was constructed by modifying MoS2/Au NS nanozyme on the SPCE using the conductive Nafion solution. And the negatively charged sulfonic acid group can eliminate negatively charged electroactive substances to improve the specificity. Then ascorbic acid was used to stimulate tumor cells to produce H2O2 as therapeutic model, an ultrasensitive chronocoulometry detection for H2O2 in cell lysate was established. The logarithmically of ΔQ and the logarithmically of H2O2 concentration showed a good linear relationship between 1 µM and 500 mM, with a LOD value of 0.3 µM. SIGNIFICANCE: The developed H2O2 sensor has excellent stability, reproducibility (RSD = 2.3 %, n = 6) and selectivity, realized the quantitative detection of H2O2 in cell lysate. Compared with commercial fluorescence detection kits for H2O2 in cell lysate, it is worth mentioning that the electrochemical H2O2 sensor developed in this study is simpler and faster, with higher sensitivity and lower cost. This provides a potential substitute for disease diagnosis and treatment evaluation based on accurate detection of H2O2.
Subject(s)
Antineoplastic Agents , Disulfides , Electrochemical Techniques , Gold , Hydrogen Peroxide , Metal Nanoparticles , Molybdenum , Gold/chemistry , Molybdenum/chemistry , Hydrogen Peroxide/analysis , Hydrogen Peroxide/chemistry , Disulfides/chemistry , Metal Nanoparticles/chemistry , Electrochemical Techniques/methods , Humans , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Antineoplastic Agents/analysis , Nanostructures/chemistry , Limit of Detection , Peroxidase/chemistry , Peroxidase/metabolism , Drug Screening Assays, AntitumorABSTRACT
Herein, the selenium (Se) modified gold nanoparticles (Se-AuNPs) was synthesized using cerium doped carbon dots (Ce-CDs) as a reducing agent and template. As desired, Se-AuNPs displays enhanced peroxidase (POD)-like activity in the presence of Hg2+. The mechanism for the enhanced activity was attributed to the increased affinity between Se-AuNPs-Hg2+ and the substrate, in which Se and Au elements have a strong binding capacity to Hg2+, forming Hg-Se bonds and Au-Hg amalgam to generate more ·OH. This POD-like activity of Se-AuNPs-Hg2+ correlates with the colorimetric reaction by the catalytic reaction between 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2. The oxidation of TMB was completely inhibited by the introduction of the reductive S2-. Based on the above findings, a strategy for the colorimetric detection of Hg2+ and S2- by Se-AuNPs was established with linear ranges of 0.33-66 µg/L and 0.625-75 µg/L, and low detection limits of 0.17 µg/L and 0.12 µg/L (3.3 δ/k), respectively. When the colorimetric probes for detection of Hg2+ and S2- was applied in environmental water samples, the recoveries were in the range of 90.3-108.0 %. This method will provide a new idea for the colorimetric detection strategy of Hg2+ due to the strong interaction between Hg and Se.
Subject(s)
Colorimetry , Gold , Mercury , Metal Nanoparticles , Selenium , Colorimetry/methods , Mercury/analysis , Gold/chemistry , Metal Nanoparticles/chemistry , Selenium/chemistry , Limit of Detection , Water Pollutants, Chemical/analysis , Benzidines/chemistry , Peroxidase/chemistry , Peroxidase/metabolism , Hydrogen Peroxide/chemistry , Hydrogen Peroxide/analysisABSTRACT
BACKGROUND: Hydrogen peroxide (H2O2) plays a vital role in human health and have been regarded as a crucial analyte in metabolic processes, redox transformations, foods research and medical fields. Especially, the long-time and excessive digestion of H2O2 may even cause severe diseases. Although conventional instrumental methods and nanozymes-based colorimetric methods have been developed to accomplish the quantitative analysis of H2O2, the drawbacks of instrument dependence, cost-effectiveness, short lifespan, non-portable and unsustainable detection efficacies will limit their applications in different detection scenarios. RESULTS: Herein, to address these challenges, we have proposed a novel strategy for nanozyme (RuO2) hydrogel preparation by the solid support from cross-linked polyvinyl alcohol (PVA) and chitosan (CS) to both inherit the dominant peroxidase-like (POD) activity and protect the RuO2 from losing efficacies. Taking advantages from the hydrogel, the encapsulated RuO2 were further prepared as the regularly spherical beads (PCRO) to exhibit the sustainable, recyclable, and robust catalysis. Moreover, the intrinsic color interferences which originated from RuO2 can be avoided by the encapsulation strategy to promote the detection accuracy. Meanwhile, the high mechanical strength of PCRO shows the high stability, reproducibility, and cyclic catalysis to achieve the recyclable detection performance and long lifetime storage (40 days), which enables the sensitively detection of H2O2 with the detection limit as lower to 15 µM and the wide detection linear range from 0.025 to 1.0 mM. SIGNIFICANCE: On the basis of the unique properties, PCRO has been further adopted to construct a smartphone detection platform to realize the instrument-free and visual analysis of H2O2 in multi-types of milk and real water samples through capturing, processing, and analyzing the RGB values from the colorimetric photographs. Therefore, PCRO with the advanced detection efficacies holds the great potential in achieving the portable and on-site analysis of targets-of-interest.
Subject(s)
Chitosan , Hydrogels , Hydrogen Peroxide , Polyvinyl Alcohol , Hydrogen Peroxide/chemistry , Hydrogen Peroxide/analysis , Chitosan/chemistry , Polyvinyl Alcohol/chemistry , Catalysis , Hydrogels/chemistry , Colorimetry , Limit of DetectionABSTRACT
The advent of wearable sensors heralds a transformation in the continuous, noninvasive analysis of biomarkers critical for disease diagnosis and fitness management. Yet, their advancement is hindered by the functional challenges affiliated with their active sensing analysis layer. Predominantly due to suboptimal intrinsic material properties and inconsistent dispersion leading to aggregation, thus compromising sensor repeatability and performance. Herein, an innovative approach to the functionalization of wearable electrochemical sensors was introduced, specifically addressing these limitations. The method involves a proton-induced self-assembly technique at the organic-water (O/W) interface, facilitating the generation of biomarker-responsive films. This research offers flexible, breathable sensor capable of real-time precision tracking l-cysteine (l-Cys) precision tracking. Utilizing an activation mechanism for Prussian blue nanoparticles by hydrogen peroxide, the catalytic core exhibits a specific response to l-Cys. The implications of this study refine the fabrication of film-based analysis electrodes for wearable sensing applications and the broader utilization of two-dimensional materials in functional-specific response films. Findings illuminate the feasibility of this novel strategy for precise biomarker tracking and extend to pave the way for constructing high-performance electrocatalytic analytical interfaces.
Subject(s)
Cysteine , Electrochemical Techniques , Ferrocyanides , Wearable Electronic Devices , Cysteine/analysis , Cysteine/chemistry , Humans , Electrochemical Techniques/instrumentation , Electrochemical Techniques/methods , Ferrocyanides/chemistry , Hydrogen Peroxide/analysis , Hydrogen Peroxide/chemistry , Electrodes , Biosensing Techniques , Biomarkers/analysis , Nanoparticles/chemistryABSTRACT
In recent years, great progress has been made on the study of nanozymes with enzyme-like properties. Here, bimetallic Fe and Ni nanoclusters were anchored on the nanosheets of nitrogen-rich layered graphitic carbon nitride by one-step pyrolysis at high temperature (Fe/Ni-CN). The loading content of Fe and Ni on Fe/Ni-CN is as high as 8.0%, and Fe/Ni-CN has a high specific surface area of 121.86 m2 g-1. The Fe/Ni-CN can effectively oxidize 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2, and exhibits efficient peroxidase-like activity, leading to a 17.2-fold increase compared to pure graphitic carbon nitride (CN). Similar to the natural horseradish peroxidase (HRP), the Fe/Ni-CN nanozyme follows catalytic kinetics. The Michaelis-Menten constant (Km) value of the Fe/Ni-CN nanozyme for TMB is about 8.3-fold lower than that for HRP, which means that the Fe/Ni-CN nanozyme has better affinity for TMB. In addition, the catalytic mechanism was investigated by combination of free radical quenching experiments and density-functional theory (DFT) calculations. The results show that the high peroxidase-like activity is due to the easy adsorption of H2O2 after bimetal loading, which is conducive to the production of hydroxyl radicals. Based on the extraordinary peroxidase-like activity, the colorimetric detection of p-phenylenediamine (PPD) was constructed with a wide linear range of 0.2-30 µM and a low detection limit of 0.02 µM. The sensor system has been successfully applied to the detection of residual PPD in real dyed hair samples. The results show that the colorimetric method is sensitive, highly selective and accurate. This study provides a new idea for the efficient enhancement of nanozyme activity and effective detection of PPD by a bimetallic synergistic strategy.
Subject(s)
Colorimetry , Graphite , Iron , Nickel , Nitrogen Compounds , Phenylenediamines , Graphite/chemistry , Phenylenediamines/chemistry , Colorimetry/methods , Nitrogen Compounds/chemistry , Nickel/chemistry , Iron/chemistry , Hydrogen Peroxide/analysis , Hydrogen Peroxide/chemistry , Nitriles/chemistry , Limit of Detection , Catalysis , Benzidines/chemistryABSTRACT
Fenton-conditioning is commonly used to improve dewatering ability for municipal biological sludge, however, its application in industries is scarce. In this study, biochar (FT-BC) was successfully synthesized from a Fenton-conditioned landfill leachate biological sludge under oxygen-limited. As compared to the corresponding blank and poly ferric-pretreated biochars (BC and PF-BC), moderate Fenton conditioning of the sludge could enable good removal performance for Cr (â ¥) by FT-BC. It was found that the oxygen central free radicals (OCFRs) on the biochar surface was intensively promoted due to Fenton electrophilic addition of ·OH onto the oxygen-containing functional groups in biomass. The amounts of OCFRs correlated positively well with the removal efficiency, indicating these persistent free radicals (PFRs)would mainly responsible for the reductive immobilization of Cr(VI)on the FT-BC surface. This study is expected to provide a new method for reclamation of industrial biological sludges with poor agglomeration by introducing simple Fenton pre-conditioning.
Subject(s)
Charcoal , Sewage , Charcoal/chemistry , Sewage/chemistry , Free Radicals/chemistry , Chromium/chemistry , Water Pollutants, Chemical/chemistry , Iron/chemistry , Oxygen/chemistry , Hydrogen Peroxide/chemistryABSTRACT
Age-related macular degeneration (AMD) and diabetic retinopathy (DR) are common retinal diseases responsible for most blindness in working-age and elderly populations. Oxidative stress and mitochondrial dysfunction play roles in these pathogenesis, and new therapies counteracting these contributors could be of great interest. Some molecules, like coenzyme Q10 (CoQ10), are considered beneficial to maintain mitochondrial homeostasis and contribute to the prevention of cellular apoptosis. We investigated the impact of adding CoQ10 (Q) to a nutritional antioxidant complex (Nutrof Total®; N) on the mitochondrial status and apoptosis in an in vitro hydrogen peroxide (H2O2)-induced oxidative stress model in human retinal pigment epithelium (RPE) cells. H2O2 significantly increased 8-OHdG levels (p < 0.05), caspase-3 (p < 0.0001) and TUNEL intensity (p < 0.01), and RANTES (p < 0.05), caspase-1 (p < 0.05), superoxide (p < 0.05), and DRP-1 (p < 0.05) levels, and also decreased IL1ß, SOD2, and CAT gene expression (p < 0.05) vs. control. Remarkably, Q showed a significant recovery in IL1ß gene expression, TUNEL, TNFα, caspase-1, and JC-1 (p < 0.05) vs. H2O2, and NQ showed a synergist effect in caspase-3 (p < 0.01), TUNEL (p < 0.0001), mtDNA, and DRP-1 (p < 0.05). Our results showed that CoQ10 supplementation is effective in restoring/preventing apoptosis and mitochondrial stress-related damage, suggesting that it could be a valid strategy in degenerative processes such as AMD or DR.
Subject(s)
Apoptosis , Hydrogen Peroxide , Oxidative Stress , Retinal Pigment Epithelium , Ubiquinone , Humans , Ubiquinone/analogs & derivatives , Ubiquinone/pharmacology , Retinal Pigment Epithelium/metabolism , Retinal Pigment Epithelium/drug effects , Oxidative Stress/drug effects , Apoptosis/drug effects , Hydrogen Peroxide/metabolism , Hydrogen Peroxide/pharmacology , Mitochondria/metabolism , Mitochondria/drug effects , Antioxidants/pharmacology , Epithelial Cells/metabolism , Epithelial Cells/drug effects , Cell Line , Dietary SupplementsABSTRACT
Moringa oleifera is widely grown throughout the tropics and increasingly used for its therapeutic and nutraceutical properties. These properties are attributed to potent antioxidant and metabolism regulators, including glucosinolates/isothiocyanates as well as flavonoids, polyphenols, and phenolic acids. Research to date largely consists of geographically limited studies that only examine material available locally. These practices make it unclear as to whether moringa samples from one area are superior to another, which would require identifying superior variants and distributing them globally. Alternatively, the finding that globally cultivated moringa material is essentially functionally equivalent means that users can easily sample material available locally. We brought together accessions of Moringa oleifera from four continents and nine countries and grew them together in a common garden. We performed a metabolomic analysis of leaf extracts (MOLE) using an LC-MSMS ZenoTOF 7600 mass spectrometry system. The antioxidant capacity of leaf samples evaluated using the Total Antioxidant Capacity assay did not show any significant difference between extracts. MOLE samples were then tested for their antioxidant activity on C2C12 myotubes challenged with an oxidative insult. Hydrogen peroxide (H2O2) was added to the myotubes after pretreatment with different extracts. H2O2 exposure caused an increase in cell death that was diminished in all samples pretreated with moringa extracts. Our results show that Moringa oleifera leaf extract is effective in reducing the damaging effect of H2O2 in C2C12 myotubes irrespective of geographical origin. These results are encouraging because they suggest that the use of moringa for its therapeutic benefits can proceed without the need for the lengthy and complex global exchange of materials between regions.
Subject(s)
Antioxidants , Metabolomics , Moringa oleifera , Muscle Fibers, Skeletal , Plant Extracts , Plant Leaves , Moringa oleifera/chemistry , Moringa oleifera/metabolism , Plant Leaves/chemistry , Plant Leaves/metabolism , Antioxidants/pharmacology , Antioxidants/metabolism , Plant Extracts/pharmacology , Plant Extracts/chemistry , Metabolomics/methods , Animals , Mice , Muscle Fibers, Skeletal/metabolism , Muscle Fibers, Skeletal/drug effects , Cell Line , Hydrogen Peroxide/metabolism , Oxidative Stress/drug effects , Metabolome/drug effectsABSTRACT
Para-hydroxycinnamic acid (pHCA) is one of the most abundant naturally occurring hydroxycinnamic acids, a class of chemistries known for their antioxidant properties. In this study, we evaluated the impact of pHCA on different parameters of skin aging in in vitro skin models after H2O2 and UV exposure. These parameters include keratinocyte senescence and differentiation, inflammation, and energy metabolism, as well as the underlying molecular mechanisms. Here we demonstrate that pHCA prevents oxidative stress-induced premature senescence of human primary keratinocytes in both 2D and 3D skin models, while improving clonogenicity in 2D. As aging is linked to inflammation, referred to as inflammaging, we analyzed the release of IL-6, IL-8, and PGE2, known to be associated with senescence. All of them were downregulated by pHCA in both normal and oxidative stress conditions. Mechanistically, DNA damage induced by oxidative stress is prevented by pHCA, while pHCA also exerts a positive effect on the mitochondrial and glycolytic functions under stress. Altogether, these results highlight the protective effects of pHCA against inflammaging, and importantly, help to elucidate its potential mechanisms of action.
Subject(s)
Cellular Senescence , Coumaric Acids , Keratinocytes , Oxidative Stress , Skin Aging , Skin , Humans , Coumaric Acids/pharmacology , Cellular Senescence/drug effects , Keratinocytes/drug effects , Keratinocytes/metabolism , Oxidative Stress/drug effects , Skin/metabolism , Skin/drug effects , Skin Aging/drug effects , Inflammation/metabolism , DNA Damage/drug effects , Hydrogen Peroxide/metabolism , Ultraviolet Rays/adverse effects , Antioxidants/pharmacology , Cells, Cultured , Interleukin-8/metabolism , Interleukin-6/metabolismABSTRACT
During the development of animal organs, various adverse stimuli or toxic environments can induce oxidative stress and delay ovarian development. Paeoniflorin (PF), the main active ingredient of the traditional Chinese herb Paeonia lactiflora Pall., has protective effects on various diseases by preventing oxidative stress. However, the mechanism by which PF attenuates oxidative damage in mouse ovaries remains unclear. We evaluated the protective effects of PF on ovaries in an H2O2-induced mouse oxidative stress model. The H2O2-induced mouse ovarian oxidative stress model was used to explore the protective effect of PF on ovarian development. Histology and follicular development were observed. We then detected related indicators of cell apoptosis, oxidative stress, and autophagy in mouse ovaries. We found that PF inhibited H2O2-induced ovarian cell apoptosis and ferroptosis and promoted granulosa cell proliferation. PF prevented oxidative stress by increasing nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression levels. In addition, the autophagic flux of ovarian cells was activated and was accompanied by increased lysosomal biogenesis. Moreover, PF-mediated autophagy was involved in clearing mitochondria damaged by H2O2. Importantly, PF administration significantly increased the number of primordial follicles, primary follicles, secondary follicles, and antral follicles. PF administration improved ovarian sizes compared with the H2O2 group. The present study suggested that PF administration reversed H2O2-induced ovarian developmental delay and promoted follicle development. PF-activated mitophagy is crucial for preventing oxidative stress and improving mitochondrial quality.
Subject(s)
Glucosides , Hydrogen Peroxide , Mitophagy , Ovary , Oxidative Stress , Animals , Female , Oxidative Stress/drug effects , Glucosides/pharmacology , Mice , Ovary/drug effects , Ovary/metabolism , Mitophagy/drug effects , Hydrogen Peroxide/metabolism , Monoterpenes/pharmacology , Apoptosis/drug effects , Autophagy/drug effects , Heme Oxygenase-1/metabolism , Cell Proliferation/drug effects , NF-E2-Related Factor 2/metabolism , Granulosa Cells/drug effects , Granulosa Cells/metabolismABSTRACT
Peroxiporins are a specialized subset of aquaporins, which are integral membrane proteins primarily known for facilitating water transport across cell membranes. In addition to the classical water transport function, peroxiporins have the unique capability to transport hydrogen peroxide (H2O2), a reactive oxygen species involved in various cellular signaling pathways and regulation of oxidative stress responses. The regulation of H2O2 levels is crucial for maintaining cellular homeostasis, and peroxiporins play a significant role in this process by modulating its intracellular and extracellular concentrations. This ability to facilitate the passage of H2O2 positions peroxiporins as key players in redox biology and cellular signaling, with implications for understanding and treating various diseases linked to oxidative stress and inflammation. This review provides updated information on the physiological roles of peroxiporins and their implications in disease, emphasizing their potential as novel biomarkers and drug targets in conditions where they are dysregulated, such as inflammation and cancer.