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Redox Biology Jun 2024Ferroptosis, a lipid peroxidation-driven cell death program kept in check by glutathione peroxidase 4 and endogenous redox cycles, promises access to novel strategies...
Ferroptosis, a lipid peroxidation-driven cell death program kept in check by glutathione peroxidase 4 and endogenous redox cycles, promises access to novel strategies for treating therapy-resistant cancers. Chlorido [N,N'-disalicylidene-1,2-phenylenediamine]iron (III) complexes (SCs) have potent anti-cancer properties by inducing ferroptosis, apoptosis, or necroptosis through still poorly understood molecular mechanisms. Here, we show that SCs preferentially induce ferroptosis over other cell death programs in triple-negative breast cancer cells (LC ≥ 0.07 μM) and are particularly effective against cell lines with acquired invasiveness, chemo- or radioresistance. Redox lipidomics reveals that initiation of cell death is associated with extensive (hydroper)oxidation of arachidonic acid and adrenic acid in membrane phospholipids, specifically phosphatidylethanolamines and phosphatidylinositols, with SCs outperforming established ferroptosis inducers. Mechanistically, SCs effectively catalyze one-electron transfer reactions, likely via a redox cycle involving the reduction of Fe(III) to Fe(II) species and reversible formation of oxo-bridged dimeric complexes, as supported by cyclic voltammetry. As a result, SCs can use hydrogen peroxide to generate organic radicals but not hydroxyl radicals and oxidize membrane phospholipids and (membrane-)protective factors such as NADPH, which is depleted from cells. We conclude that SCs catalyze specific redox reactions that drive membrane peroxidation while interfering with the ability of cells, including therapy-resistant cancer cells, to detoxify phospholipid hydroperoxides.
PubMed: 38955113
DOI: 10.1016/j.redox.2024.103257 -
Journal of Environmental Management Jul 2024Effective elimination of heavy metals from complex wastewater is of great significance for industrial wastewater treatment. Herein, bimetallic adsorbent FeO-CeO was...
Effective elimination of heavy metals from complex wastewater is of great significance for industrial wastewater treatment. Herein, bimetallic adsorbent FeO-CeO was prepared, and HO was added to enhance Sb(V) adsorption by FeO-CeO in complex wastewater of Sb(V) and aniline aerofloat (AAF) for the first time. FeO-CeO showed good adsorption performance and could be rapidly separated by external magnetic field. After five adsorption/desorption cycles, FeO-CeO still maintained good stability. The maximum adsorption capacities of FeO-CeO in single Sb(V), AAF + Sb(V), and HO+AAF + Sb(V) systems were 77.33, 70.14, and 80.59 mg/g, respectively. Coexisting AAF inhibited Sb(V) adsorption. Conversely, additional HO promoted Sb(V) removal in AAF + Sb(V) binary system, and made the adsorption capacity of FeO-CeO increase by 14.90%. HO could not only accelerate the reaction rate, but also reduce the optimal amount of adsorbent from 2.0 g/L to 1.2 g/L. Meanwhile, coexisting anions had little effect on Sb(V) removal by FeO-CeO+HO process. The adsorption behaviors of Sb(V) in three systems were better depicted by pseudo-second-order kinetics, implying that the chemisorption was dominant. The complexation of AAF with Sb(V) hindered the adsorption of Sb(V) by FeO-CeO. The complex Sb(V) was oxidized and decomposed into free state by hydroxyl radicals produced in FeO-CeO+HO process. Then the free Sb(V) was adsorbed by FeO-CeO mostly through outer-sphere complexation. This work provides a new tactic for the treatment of heavy metal-organics complex wastewater.
PubMed: 38955048
DOI: 10.1016/j.jenvman.2024.121610 -
Journal of Colloid and Interface Science Jun 2024A heterojunction of trace CoO bonded on oxygen vacancies (OVs)-rich ZnO (OVs-ZnO/CoO) was synthesized via defect-assisted method to promote peroxymonosulfate (PMS)...
A heterojunction of trace CoO bonded on oxygen vacancies (OVs)-rich ZnO (OVs-ZnO/CoO) was synthesized via defect-assisted method to promote peroxymonosulfate (PMS) activation and pollutants degradation. Experiments and theoretical calculations demonstrated that electrons could efficiently transfer from OVs-ZnO to CoO. OVs-ZnO and CoO played different roles in activating PMS. PMS was easily adsorbed on the OVs-ZnO to form PMS* complex and mediated electron transfer to oxide ciprofloxacin (CIP), whereas, CoO facilitated breakup of peroxide bond to produce radicals. The optimal OVs-ZnO/CoO with Co content of 1.34% exhibited good PMS decomposition ability (94.2% in 30 min) compared to unmodified ZnO (24.2%), stability and anti-interference feature in removing CIP, 96.9% CIP (10 ppm) and 79.6% of total organic carbon were removed in 30 min. Moreover, the OVs-ZnO/CoO achieved 91.2% CIP removal ratio with 1.0 mM PMS via a flow-through device in 180 min. This study proposes a new strategy to enhance PMS activation of ZnO and provides new viewpoint in PMS activation way.
PubMed: 38955012
DOI: 10.1016/j.jcis.2024.06.224 -
Journal of Colloid and Interface Science Jun 2024The CO preferential oxidation reaction (CO-PROX) is an effective strategy to remove residual poisonous CO in proton exchange membrane fuel cells, in which oxygen...
The CO preferential oxidation reaction (CO-PROX) is an effective strategy to remove residual poisonous CO in proton exchange membrane fuel cells, in which oxygen vacancies play a critical role in CO adsorption and activation. Herein, a series of CuO/CeO catalysts derived from Ce-MOFs precursors were synthesized using different organic ligands via the hydrothermal method and the CO-PROX performance was investigated. The CuO/CeO-135 catalyst derived from homophthalic tricarboxylic acid (1,3,5-HBTC) exhibited superior catalytic performance with 100 % CO conversion at a relatively low temperature (T = 100 °C), with a wide reaction temperature range and excellent stability. The superior catalytic properties were attributed to the structural improvements provided by the 1,3,5-HBTC precursors and the promotional effects of oxygen vacancies. Additionally, in-situ Raman spectroscopy was performed to verify the dynamic roles of oxygen vacancies for CO adsorption and activation, while in-situ DRIFTS analysis revealed key intermediates in the CO-PROX reaction, shedding light on the mechanistic aspects of the catalytic process. This work not only demonstrates insights into the effective CuO/CeO catalysts for CO preferential oxidation, but also provides a feasible way to synthesize MOF-derived catalysts.
PubMed: 38955009
DOI: 10.1016/j.jcis.2024.06.110 -
Waste Management (New York, N.Y.) Jul 2024Climate impacts of landfill gas emissions were investigated for 20- and 100-year time horizons to identify the effects of atmospheric lifetimes of short- and long-lived...
Climate impacts of landfill gas emissions were investigated for 20- and 100-year time horizons to identify the effects of atmospheric lifetimes of short- and long-lived drivers. Direct and indirect climate impacts were determined for methane and 79 trace species. The impacts were quantified using global warming potential, GWP (direct and indirect); atmospheric degradation (direct); tropospheric ozone forming potential (indirect); secondary aerosol forming potential (indirect) and stratospheric ozone depleting potential (indirect). Effects of cover characteristics, landfill operational conditions, and season on emissions were assessed. Analysis was conducted at five operating municipal solid waste landfills in California, which collectively contained 13% of the waste in place in the state. Climate impacts were determined to be primarily due to direct emissions (99.5 to 115%) with indirect emissions contributing -15 to 0.5%. Methane emissions were 35 to 99% of the total emissions and the remainder mainly greenhouse gases (hydro)chlorofluorocarbons (up to 42% of total emissions) and nitrous oxide. Cover types affected emissions, where the highest emissions were generally from intermediate covers with the largest relative landfill surface areas. Landfill-specific direct emissions varied between 683 and 103,411 and between 381 and 37,925 Mg CO-eq./yr for 20- and 100-yr time horizons, respectively. Total emissions (direct + indirect) were 680 to 103,600 (20-yr) and were 374 to 38,108 (100-yr) Mg CO-eq./yr. Analysis time horizon significantly affected emissions. The 20-yr direct and total emissions were consistently higher than the 100-yr emissions by up to 2.5 times. Detailed analysis of time-dependent climate effects can inform strategies to mitigate climate change impacts of landfill gas emissions.
PubMed: 38954923
DOI: 10.1016/j.wasman.2024.06.015 -
Ecotoxicology and Environmental Safety Jul 2024In most of advanced oxidation processes (AOPs) used to destroy harmful organic chemicals in water/wastewater hydroxyl radical (OH) reactions oxidize (increasing the...
In most of advanced oxidation processes (AOPs) used to destroy harmful organic chemicals in water/wastewater hydroxyl radical (OH) reactions oxidize (increasing the oxygen/carbon ratio in the molecules) and mineralize (transforming them to inorganic molecules, HO, CO, etc.) these contaminants. In this paper, we used the radiolysis of water to produce OH and characterised the rate of oxidation and mineralization by the dose dependences of the Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) content values. Analysis of the dose dependences for 34 harmful organic compounds showed large differences in the oxidation and mineralization rates and these parameters are characteristic to the given group of chemicals. E.g., the rate of oxidation is relatively low for fluoroquinolone antibiotics; it is high for β-blocker medicines. Mineralization rates are low for both fluoroquinolones and β-blockers. The one-electron-oxidant OH in most cases induces two - four-electron-oxidations. Most of the degradation takes place gradually, through several stable molecule intermediates. However, based on the results it is likely, that some part of the oxidation and mineralization takes place parallel. The organic radicals formed in OH reactions react with several O molecules and release several inorganic fragments during the radical life cycle.
PubMed: 38954908
DOI: 10.1016/j.ecoenv.2024.116669 -
Journal of Hazardous Materials Jun 2024A redox co-precipitation method was employed to synthesize CeMn homogeneous solid solutions, utilizing various alcohols as activating agents. Ethanol effectively...
A redox co-precipitation method was employed to synthesize CeMn homogeneous solid solutions, utilizing various alcohols as activating agents. Ethanol effectively orchestrated the precipitation of CeO and MnO, promoting their co-growth. As a result, the CeMn-EA achieved 90 % toluene conversion at 218 ℃ (T =218 ℃) with a weight hourly space velocity (WHSV) of 48000 ml/(g·h). It also demonstrated high adaptability to increased WHSV, suggesting its potential for industrial-scale applications. The uniform dispersion of Ce and Mn accelerated the coupling between Ce/Ce and Mn/Mn, engineering numerous oxygen vacancies, which enhanced the activation of gas-phase oxygen and the mobility of lattice oxygen. In situ DRIFTS confirmed that toluene oxidation accommodated both Langmuir-Hinshelwood (L-H) and Mars-van Krevelen (MvK) mechanisms, with benzoate identified as a pivotal intermediate. Enhanced oxygen mobility facilitated the cleavage of the benzene ring, which was the rate-determining step. Additionally, the introduction of HO significantly enhanced the dissociation and adsorption of toluene and facilitated the activation of gas-phase oxygen. At higher temperatures, HO could further activate lattice oxygen engaging in toluene oxidation. ENVIRONMENTAL IMPLICATION: Volatile organic compounds (VOCs) have emerged as major air pollutants due to the changes in air pollution patterns. They can act as precursors to near-surface ozone and haze. Toluene, a typical VOC, is primarily released from anthropogenic sources and poses significant risks to human health and the environment. Ce-based catalysts have been demonstrated efficiency in toluene oxidation due to their excellent oxygen storage and release properties. This study synthesized CeMn homogeneous solid solutions utilizing various alcohols as activating agents, which possessed abundant oxygen vacancies and optimum oxygen activation capacity to oxidize toluene in time.
PubMed: 38954854
DOI: 10.1016/j.jhazmat.2024.135051 -
Journal of the American Chemical Society Jul 2024Molecular switches have received major attention to enable the reversible modulation of various molecular properties and have been extensively used as trigger elements...
Molecular switches have received major attention to enable the reversible modulation of various molecular properties and have been extensively used as trigger elements in diverse fields, including molecular machines, responsive materials, and photopharmacology. Antiaromaticity is a fascinating property that has attracted not only significant fundamental interest but is also increasingly relevant in different applications, in particular organic (opto)electronics. However, designing systems in which (anti)aromaticity can be judiciously and reversibly switched ON and OFF remains challenging. Herein, we report a helicene featuring an indenofluorene-bridged bisthioxanthylidene as a novel switch wherein a simultaneous two-electron (electro)chemical redox process allows highly reversible modulation of its (anti)aromatic character. Specifically, the two thioxanthylidene rotors, attached to the initially aromatic indenofluorene scaffold via overcrowded alkenes, adopt an -folded structure, which upon oxidation convert to singly bonded, twisted conformations. This is not only associated with significant (chir)optical changes but importantly also results in formation of the fully conjugated, formally antiaromatic -indacene motif in the helical core of the switch. This process proceeds without the buildup of radical cation intermediates and thus enables highly reversible switching of molecular geometry, aromaticity, absorbance, and chiral expression under ambient conditions, as evidenced by NMR, UV-vis, CD, and (spectro)electrochemical analyses, supported by DFT calculations. We expect this concept to be extendable to a wide range of robust antiaromatic-aromatic switches and to provide a basis for modulation of the structure and properties of these fascinating inherently chiral polycyclic π-scaffolds.
PubMed: 38954739
DOI: 10.1021/jacs.4c04191 -
Langmuir : the ACS Journal of Surfaces... Jul 2024The synergistic treatment of oily wastewater containing organic hazards and emulsified oils remains a big challenge for membrane separation technology. Herein, the...
Photocatalytic PAN Nanofibrous Membrane through Anchoring a Nanoflower-Branched CoAl-LDH@PANI Heterojunction for Organic Hazards Degradation and Oil-Containing Emulsified Wastewater Separation.
The synergistic treatment of oily wastewater containing organic hazards and emulsified oils remains a big challenge for membrane separation technology. Herein, the photocatalytic membrane, which combined the physical barrier and catalytic oxidation-driven degradation functionality, was fabricated via anchoring a nanoflower-branched CoAl-LDH@PANI Z-scheme heterojunction onto a porous polyacrylonitrile mat and using tannic acid as an adhesive. The assembly of such a Z-scheme heterojunction offered the superior photocatalytic degradation performance of soluble dyes and tetracycline (up to 94.3%) to the membrane with the improved photocatalytic activity of 2.33 times compared with the CoAl-LDH@pPAN membrane. Quenching experiments suggested that the O was the most reactive oxygen species in the catalytic reaction system of the composite membrane. The greatly enhanced photocatalytic activity was attributed to the effective inhibition of photogenerated hole-electron combination using PANI as a carrier, with charge transferring from LDH to PANI. The possible photocatalytic degradation mechanism was proposed based on VB-XPS, electron spin resonance spectroscopy, and DRS technologies, which was confirmed by density functional theory calculation. Meanwhile, benefiting from the superhydrophilic/oleophobic feature and low oil adhesion, the membrane exhibited high permeability for isooctane emulsion (3990.39 L·m·h), high structure stability, and satisfactory cycling performance. This work provided a strategy to develop superwetting and photocatalytic composite membranes for treating complex multicomponent pollutants in the chemical industry.
PubMed: 38954527
DOI: 10.1021/acs.langmuir.4c00980 -
ACS Applied Materials & Interfaces Jul 2024In the intricate landscape of Traumatic Brain Injury (TBI), the management of TBI remains a challenging task due to the extremely complex pathophysiological conditions...
Logic "AND Gate Circuit" Based Mussel Inspired Polydopamine Nanocomposite as Bioactive Antioxidant for Management of Oxidative Stress and Neurogenesis in Traumatic Brain Injury.
In the intricate landscape of Traumatic Brain Injury (TBI), the management of TBI remains a challenging task due to the extremely complex pathophysiological conditions and excessive release of reactive oxygen species (ROS) at the injury site and the limited regenerative capacities of the central nervous system (CNS). Existing pharmaceutical interventions are limited in their ability to efficiently cross the blood-brain barrier (BBB) and expeditiously target areas of brain inflammation. In response to these challenges herein, we designed novel mussel inspired polydopamine (PDA)-coated mesoporous silica nanoparticles (PDA-AMSNs) with excellent antioxidative ability to deliver a new potential therapeutic GSK-3β inhibitor lead small molecule abbreviated as Neuro Chemical Modulator (NCM) at the TBI site using a neuroprotective peptide hydrogel (PANAP). PDA-AMSNs loaded with NCM (i.e., PDA-AMSN-D) into the matrix of PANAP were injected into the damaged area in an cryogenic brain injury model (CBI). This approach is specifically built while keeping the logic AND gate circuit as the primary focus. Where NCM and PDA-AMSNs act as two input signals and neurological functional recovery as a single output. Therapeutically, PDA-AMSN-D significantly decreased infarct volume, enhanced neurogenesis, rejuvenated BBB senescence, and accelerated neurological function recovery in a CBI.
PubMed: 38954488
DOI: 10.1021/acsami.4c07694