Visual detection and discrimination of nerve and blood agents using a dual-site fluorescent probe in living cells and mice.

Of all chemical warfare agents (CWAs), only nerve and blood agents cause massive mortality at low concentrations. To better detect and discriminate nerve and blood agents, a reliable detection method is desirable. We report a series of fluorescent probes for nerve and blood agent detection. Among the tested probes, SR-Pip detected nerve and blood agents quickly (within 10 s for nerve agents and 1 min for blood agents). SR-Pip coupled with nerve agent produced a weak orange fluorescence with good sensitivity [limit of detection (LOD)= 5.5 µM]. Upon reaction with blood agent, the fluorescence of SR-Pip changed from orange fluorescence to blue fluorescence with detection limits as low as 9.6 nM. This probe effectively visualised different concentrations of nerve agents in living cells and mice. A portable test kit using SR-Pip instantly detected nerve and blood agents. To the best of our knowledge, SR-Pip is the first fluorescent probe for nerve and blood agent detection.

Oxidative Stress: An Intersection Between Radiation and Sulfur Mustard Lung Injury.

Nuclear and chemical weapons of mass destruction share both a tragic and beneficial legacy in mankind's history and health. The horrific health effects of ionizing radiation and mustard gas exposures unleashed during disasters, wars, and conflicts have been harnessed to treat human health maladies. Both agents of destruction have been transformed into therapies to treat a wide range of cancers. The discovery of therapeutic uses of radiation and sulfur mustard was largely due to observations by clinicians treating victims of radiation and sulfur mustard gas exposures. Clinicians identified vulnerability of leukocytes to these agents and repurposed their use in the treatment of leukemias and lymphomas. Given the overlap in therapeutic modalities, it goes to reason that there may be common mechanisms to target as protective strategies against their damaging effects. This commentary will highlight oxidative stress as a common mechanism shared by both radiation and sulfur mustard gas exposures and discuss potential therapies targeting oxidative stress as medical countermeasures against the devastating lung diseases wrought by these agents.

Revealing nitrogenous VX metabolites and the whole-molecule VX metabolism in the urine of guinea pigs.

VX, a well-known organophosphorus nerve agent (OPNA), poses a significant threat to public safety if employed by terrorists. Obtaining complete metabolites is critical to unequivocally confirm its alleged use/exposure and elucidate its whole-molecular metabolism. However, the nitrogenous VX metabolites containing 2-diisopropylaminoethyl moiety from urinary excretion remain unknown. Therefore, this study applied a newly developed untargeted workflow platform to discover and identify them using VX-exposed guinea pigs as animal models. 2-(N,N-diisopropylamino)ethanesulfonic acid (DiPSA) was revealed as a novel nitrogenous VX metabolite in urine, and 2-(Diisopropylaminoethyl) methyl sulfide (DAEMS) was confirmed as another in plasma, indicating that VX metabolism differed between urine and plasma. It is the first report of a nitrogenous VX metabolite in urine and a complete elucidation of the VX metabolic pathway. DiPSA was evaluated as an excellent VX exposure biomarker. The whole-molecule VX metabolism in urine was characterized entirely for the first time via the simultaneous quantification of DiPSA and two known P-based biomarkers. About 52.1% and 32.4% of VX were excreted in urine as P-based and nitrogenous biomarkers within 24 h. These findings provide valuable insights into the unambiguous detection of OPNA exposure/intoxication and human and environmental exposure risk assessment.

Pulmonary rehabilitation in Iranian outpatients with mustard gas lung disease: a randomised controlled trial.

OBJECTIVE: People with mustard gas lung disease experience cough, sputum, breathlessness and exercise limitation. We hypothesised that pulmonary rehabilitation (PR) would be beneficial in this condition. DESIGN: An assessor-blind, two-armed, parallel-design randomised controlled clinical trial. SETTING: Secondary care clinics in Iran. PARTICIPANTS: 60 men with breathlessness due to respiratory disease caused by documented mustard gas exposure, mean (SD) age 52.7 (4.36) years, MRC dyspnoea score 3.5 (0.7), St. George's Respiratory Questionnaire (SGRQ) 72.3 (15.2). INTERVENTIONS: Participants were allocated either to a 6-week course of thrice-weekly PR (n=31) or to usual care (n=29), with 6-week data for 28 and 26, respectively. OUTCOME MEASURES: Primary endpoint was change in cycle endurance time at 70% baseline exercise capacity at 6 weeks. Secondary endpoints included 6 min walk distance, quadriceps strength and bulk, body composition and health status. For logistical reasons, blood tests that had been originally planned were not performed and 12-month follow-up was available for only a small proportion. RESULTS: At 6 weeks, cycle endurance time increased from 377 (140) s to 787 (343) s with PR vs 495 (171) s to 479 (159) s for usual care, effect size +383 (231) s (p<0.001). PR also improved 6 min walk distance+103.2 m (63.6-142.9) (p<0.001), MRC dyspnoea score -0.36 (-0.65 to -0.07) (p=0.016) and quality of life; SGRQ -8.43 (-13.38 to -3.48) p<0.001, as well as quadriceps strength+9.28 Nm (1.89 to 16.66) p=0.015. CONCLUSION: These data suggest that PR can improve exercise capacity and quality of life in people with breathlessness due to mustard gas lung disease and support the wider provision of this form of care. TRIAL REGISTRATION NUMBER: IRCT2016051127848N1.

Galectin-3 inhibition ameliorates alveolar epithelial cell pyroptosis in phosgene-induced acute lung injury.

Phosgene is a type of poisonous gas that can cause acute lung injury (ALI) upon accidental exposure. Casualties still occur due to phosgene-induced acute lung injury (P-ALI) from accidents resulting from improper operations. The pathological mechanisms of P-ALI are still understudied. Thus, we performed scRNA-seq on cells isolated from all subpopulations of the BALF in P-ALI and found that Gal3 expression was significantly higher in the gas group than in the control group. Further analysis revealed a ligand-receptor correspondence between alveolar macrophages (AMs) and alveolar epithelial cells (AEC), with Gal3 playing a key role in this interaction. To confirm and elaborate on this discovery, we selected four time points during the previous week: sham (day 0), day 1, day 3, and day 7 in the P-ALI mouse model and found that Gal3 expression was significantly elevated in P-ALI, most abundantly expressed in AM cells. This was further confirmed with the use of a Gal3 inhibitor. The inhibition of Gal3 and elimination of AMs in mice both attenuated epithelial cell pyroptosis, as confirmed in in vitro experiments, and revealed the Gal3/caspase-8/GSDMD signaling pathway. These findings suggest that Galectin-3 inhibition can ameliorate AEC pyroptosis by inhibiting the Gal3/caspase-8/GSDMD signaling pathway, thus reducing alveolar damage in mice with P-ALI. This finding provides novel insights for improving treatment efficacy for P-ALI.

Chromogenic Detection of the Organophosphorus Nerve Agent Simulant DCP Mediated by Rhodium(II,II) Paddlewheel Complexes.

Organophosphorus nerve agents (OPNAs) pose a great threat to humanity. Possessing extreme toxicity, rapid lethality, and an unassuming appearance, these chemical warfare agents must be quickly and selectively identified so that treatment can be administered to those affected. Chromogenic detection is the most convenient form of OPNA detection, but current methods suffer from false positives. Here, nitrogenous base adducts of dirhodium(II,II) acetate were synthesized and used as chromogenic detectors of diethyl chlorophosphate (DCP), an OPNA simulant. UV-vis spectrophotometry was used to evaluate the sensitivity and selectivity of the complexes in the detection of DCP. Visual limits of detection (LOD) for DCP were as low as 1.5 mM DCP, while UV-vis-based LODs were as low as 0.113 µM. The dirhodium(II,II) complexes were also tested with several potential interferents, none of which produced a visual color change that could be mistaken for OPNA response. Ultimately, the Rh2(OAc)4(1,8-diazabicyclo[5.4.0]undec-7-ene)2 complex showed the best combination of detection capability and interferent resistance. These results, when taken together, show that dirhodium(II,II) paddlewheel complexes with nitrogenous base adducts can produce instant, selective, and sensitive detection of DCP. It is our aim to further explore and apply this new motif to produce even more capable OPNA sensors.

Effective skin decontamination with RSDL® (reactive skin decontamination lotion kit) following dermal exposure to a Novichok class nerve agent.

In recent years, various poisoning incidents have been reported, involving the alleged use of the so-called Novichok agents, resulting in their addition to the Schedule I list of the Organisation for the Prohibition of Chemical Warfare (OPCW). As the physicochemical properties of these agents are different from the 'classical' nerve agents, such as VX, research is needed to evaluate whether and to what extent existing countermeasures are effective. Here, we evaluated the therapeutic potential of RSDL® (Reactive Skin Decontamination Lotion Kit) for the neutralization of percutaneous toxicity caused by Novichok agents, both in vitro and in vivo. Experiments showed the three selected Novichok agents (A230, A232, A234) could be degraded by RSDL lotion, but at a different rate. The half-life of A234, in the presence of an excess of RSDL lotion, was 36 min, as compared to A230 (<5 min) and A232 (18 min). Following dermal exposure of guinea pigs to A234, application of the RSDL kit was highly effective in preventing intoxication, even when applied up until 30 min following exposure. Delayed use of the RSDL kit until the appearance of clinical signs of intoxication (3-4 h) was not able to prevent intoxication progression and deaths. This study determines RSDL decontamination as an effective treatment strategy for dermal exposure to the Novichok agent A234 and underscores the importance of early, forward use of skin decontamination, as rapidly as possible.

Dexamethasone sodium phosphate loaded nanoparticles for prevention of nitrogen mustard induced corneal injury.

Nitrogen mustard (NM) is a potent vesicating chemical warfare agent that is primarily absorbed through skin, inhalation, or ocular surface. Ocular exposure of NM can cause acute to chronic keratopathy which can eventually lead to blindness. There is a current lack of effective countermeasures against ocular exposure of NM despite their imperative need. Herein, we aim to explore the sustained effect of Dexamethasone sodium phosphate (DSP)-loaded polymeric nanoparticles (PLGA-DSP-NP) following a single subconjunctival injection in the management and prevention of corneal injury progression upon exposure to NM. DSP is an FDA approved corticosteroid with proven anti-inflammatory properties. We formulated PLGA-DSP-NP with zinc chelation ion bridging method using PLGA polymer, with particles of approximately 250 nm and a drug loading of 6.5 wt%. Under in vitro sink conditions, PLGA-DSP-NP exhibited a sustained drug release for two weeks. Notably, in NM injured cornea, a single subconjunctival (SCT) injection of PLGA-DSP-NP outperformed DSP eyedrops (0.1%), DSP solution, placebo NP, and saline, significantly mitigating corneal neovascularization, ulceration, and opacity for the two weeks study period. Through PLGA-DSP-NP injection, sustained DSP release hindered inflammatory cytokine recruitment, angiogenic factors, and endothelial cell proliferation in the cornea. This strategy presents a promising localized corticosteroid delivery system to effectively combat NM-induced corneal injury, offering insights into managing vesicant exposure.

Chloropicrin induced ocular injury: Biomarkers, potential mechanisms, and treatments.

Ocular tissue, especially the cornea, is overly sensitive to chemical exposures. The availability and adoption of chemical threat agent chloropicrin (CP) is growing in the United States as a pesticide and fumigant; thereby increasing the risk of its use in warfare, terrorist attacks and non-intentional exposure. Exposure to CP results in immediate ocular, respiratory, and dermal injury; however, we lack knowledge on its mechanism of toxicity as well as of its breakdown products like chlorine and phosgene, and effective therapies are elusive. Herein, we have reviewed the recent findings on exposure route, toxicity and likely mechanisms of CP induced ocular toxicity based on other vesicating chemical warfare agents that cause ocular injury. We have focused on the implication of their toxicity and mechanistic outcomes in the ocular tissue, especially the cornea, which could be useful in the development of broad-spectrum effective therapeutic options. We have discussed on the potential countermeasures, overall hallmarks and challenges involved in studying ocular injuries from chemical threat agent exposures. Finally, we reviewed useful available technologies and methods that can assist in the identification of effective medical countermeasures for chemical threat agents related ocular injuries.

Identification of early events in nitrogen mustard pulmonary toxicity that are independent of infiltrating inflammatory cells using precision cut lung slices.

Nitrogen mustard (NM; mechlorethamine) is a cytotoxic vesicant known to cause acute lung injury which can progress to chronic disease. Due to the complex nature of NM injury, it has been difficult to analyze early responses of resident lung cells that initiate inflammation and disease progression. To investigate this, we developed a model of acute NM toxicity using murine precision cut lung slices (PCLS), which contain all resident lung cell populations. PCLS were exposed to NM (1-100 µM) for 0.5-3 h and analyzed 1 and 3 d later. NM caused a dose-dependent increase in cytotoxicity and a reduction in metabolic activity, as measured by LDH release and WST-1 activity, respectively. Optimal responses were observed with 50 µM NM after 1 h incubation and these conditions were used in further experiments. Analysis of PCLS bioenergetics using an Agilent Seahorse showed that NM impaired both glycolytic activity and mitochondrial respiration. This was associated with injury to the bronchial epithelium and a reduction in methacholine-induced airway contraction. NM was also found to cause DNA damage in bronchial epithelial cells in PCLS, as measured by expression of γ-H2AX, and to induce oxidative stress, which was evident by a reduction in glutathione levels and upregulation of the antioxidant enzyme catalase. Cleaved caspase-3 was also upregulated in airway smooth muscle cells indicating apoptotic cell death. Characterizing early events in NM toxicity is key in identifying therapeutic targets for the development of efficacious countermeasures.

The risk associated with organophosphorus nerve agents: from their discovery to their unavoidable threat, current medical countermeasures and perspectives.

The first organophosphorus nerve agent was discovered accidently during the development of pesticides, shortly after the first use of chemical weapons (chlorine, phosgene) on the battlefield during World War I. Despite the Chemical Weapons Convention banning these substances, they have still been employed in wars, terrorist attacks or political assassinations. Characterised by their high lethality, they target the nervous system by inhibiting the acetylcholinesterase (AChE) enzyme, preventing neurotransmission, which, if not treated rapidly, inevitably leads to serious injury or the death of the person intoxicated. The limited efficacy of current antidotes, known as AChE reactivators, pushes research towards new treatments. Numerous paths have been explored, from modifying the original pyridinium oximes to developing hybrid reactivators seeking a better affinity for the inhibited AChE. Another crucial approach resides in molecules more prone to cross the blood-brain barrier: uncharged compounds, bio-conjugated reactivators or innovative formulations. Our aim is to raise awareness on the threat and toxicity of organophosphorus nerve agents and to present the main synthetic efforts deployed since the first AChE reactivator, to tackle the task of efficiently treating victims of these chemical warfare agents.

Biomarker profiling in plants to distinguish between exposure to chlorine gas and bleach using LC-HRMS/MS and chemometrics.

Since its first employment in World War I, chlorine gas has often been used as chemical warfare agent. Unfortunately, after suspected release, it is difficult to prove the use of chlorine as a chemical weapon and unambiguous verification is still challenging. Furthermore, similar evidence can be found for exposure to chlorine gas and other, less harmful chlorinating agents. Therefore, the current study aims to use untargeted high resolution mass spectrometric analysis of chlorinated biomarkers together with machine learning techniques to be able to differentiate between exposure of plants to various chlorinating agents. Green spire (Euonymus japonicus), stinging nettle (Urtica dioica), and feathergrass (Stipa tenuifolia) were exposed to 1000 and 7500 ppm chlorine gas and household bleach, pool bleach, and concentrated sodium hypochlorite. After sample preparation and digestion, the samples were analyzed by liquid chromatography high resolution tandem mass spectrometry (LC-HRMS/MS) and liquid chromatography tandem mass spectrometry (LC-MS/MS). More than 150 chlorinated compounds including plant fatty acids, proteins, and DNA adducts were tentatively identified. Principal component analysis (PCA) and linear discriminant analysis (LDA) showed clear discrimination between chlorine gas and bleach exposure and grouping of the samples according to chlorine concentration and type of bleach. The identity of a set of novel biomarkers was confirmed using commercially available or synthetic reference standards. Chlorodopamine, dichlorodopamine, and trichlorodopamine were identified as specific markers for chlorine gas exposure. Fenclonine (Cl-Phe), 3-chlorotyrosine (Cl-Tyr), 3,5-dichlorotyrosine (di-Cl-Tyr), and 5-chlorocytosine (Cl-Cyt) were more abundantly present in plants after chlorine contact. In contrast, the DNA adduct 2-amino-6-chloropurine (Cl-Ade) was identified in both types of samples at a similar level. None of these chlorinated biomarkers were observed in untreated samples. The DNA adducts Cl-Cyt and Cl-Ade could clearly be identified even three months after the actual exposure. This study demonstrates the feasibility of forensic biomarker profiling in plants to distinguish between exposure to chlorine gas and bleach.

Role of macrophage bioenergetics in N-acetylcysteine-mediated mitigation of lung injury and oxidative stress induced by nitrogen mustard.

Nitrogen mustard (NM) is a toxic vesicant that causes acute injury to the respiratory tract. This is accompanied by an accumulation of activated macrophages in the lung and oxidative stress which have been implicated in tissue injury. In these studies, we analyzed the effects of N-acetylcysteine (NAC), an inhibitor of oxidative stress and inflammation on NM-induced lung injury, macrophage activation and bioenergetics. Treatment of rats with NAC (150 mg/kg, i.p., daily) beginning 30 min after administration of NM (0.125 mg/kg, i.t.) reduced histopathologic alterations in the lung including alveolar interstitial thickening, blood vessel hemorrhage, fibrin deposition, alveolar inflammation, and bronchiolization of alveolar walls within 3 d of exposure; damage to the alveolar-epithelial barrier, measured by bronchoalveolar lavage fluid protein and cells, was also reduced by NAC, along with oxidative stress as measured by heme oxygenase (HO)-1 and Ym-1 expression in the lung. Treatment of rats with NAC attenuated the accumulation of macrophages in the lung expressing proinflammatory genes including Ptgs2, Nos2, Il-6 and Il-12; macrophages expressing inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and tumor necrosis factor (TNF)α protein were also reduced in histologic sections. Conversely, NAC had no effect on macrophages expressing the anti-inflammatory proteins arginase-1 or mannose receptor, or on NM-induced increases in matrix metalloproteinase (MMP)-9 or proliferating cell nuclear antigen (PCNA), markers of tissue repair. Following NM exposure, lung macrophage basal and maximal glycolytic activity increased, while basal respiration decreased indicating greater reliance on glycolysis to generate ATP. NAC increased both glycolysis and oxidative phosphorylation. Additionally, in macrophages from both control and NM treated animals, NAC treatment resulted in increased S-nitrosylation of ATP synthase, protecting the enzyme from oxidative damage. Taken together, these data suggest that alterations in NM-induced macrophage activation and bioenergetics contribute to the efficacy of NAC in mitigating lung injury.

The estimation of acute oral toxicity (LD50) of G-series organophosphorus-based chemical warfare agents using quantitative and qualitative toxicology in silico methods.

The idea of this study was the estimation of the theoretical acute toxicity (t-LD50, rat, oral dose) of organophosphorus-based chemical warfare agents from the G-series (n = 12) using different in silico methods. Initially identified in Germany, the G-type nerve agents include potent compounds such as tabun, sarin, and soman. Despite their historical significance, there is a noticeable gap in acute toxicity data for these agents. This study employs qualitative (STopTox and AdmetSAR) and quantitative (TEST; CATMoS; ProTox-II and QSAR Toolbox) in silico methods to predict LD50 values, offering an ethical alternative to animal testing. Additionally, we conducted quantitative extrapolation from animals, and the results of qualitative tests confirmed the acute toxicity potential of these substances and enabled the identification of toxicophoric groups. According to our estimations, the most lethal agents within this category were GV, soman (GD), sarin (GB), thiosarin (GBS), and chlorosarin (GC), with t-LD50 values (oral administration, extrapolated from rat to human) of 0.05 mg/kg bw, 0.08 mg/kg bw, 0.12 mg/kg bw, 0.15 mg/kg bw, and 0.17 mg/kg bw, respectively. On the contrary, compounds with a cycloalkane attached to the phospho-oxygen linkage, specifically methyl cyclosarin and cyclosarin, were found to be the least toxic, with values of 2.28 mg/kg bw and 3.03 mg/kg bw. The findings aim to fill the knowledge gap regarding the acute toxicity of these agents, highlighting the need for modern toxicological methods that align with ethical considerations, next-generation risk assessment (NGRA) and the 3Rs (replacement, reduction and refinement) principles.

Effects of the nerve agent VX on hiPSC-derived motor neurons.

Poisoning with the organophosphorus nerve agent VX can be life-threatening due to limitations of the standard therapy with atropine and oximes. To date, the underlying pathomechanism of VX affecting the neuromuscular junction has not been fully elucidated structurally. Results of recent studies investigating the effects of VX were obtained from cells of animal origin or immortalized cell lines limiting their translation to humans. To overcome this limitation, motor neurons (MN) of this study were differentiated from in-house feeder- and integration-free-derived human-induced pluripotent stem cells (hiPSC) by application of standardized and antibiotic-free differentiation media with the aim to mimic human embryogenesis as closely as possible. For testing VX sensitivity, MN were initially exposed once to 400 µM, 600 µM, 800 µM, or 1000 µM VX and cultured for 5 days followed by analysis of changes in viability and neurite outgrowth as well as at the gene and protein level using µLC-ESI MS/HR MS, XTT, IncuCyte, qRT-PCR, and Western Blot. For the first time, VX was shown to trigger neuronal cell death and decline in neurite outgrowth in hiPSC-derived MN in a time- and concentration-dependent manner involving the activation of the intrinsic as well as the extrinsic pathway of apoptosis. Consistent with this, MN morphology and neurite network were altered time and concentration-dependently. Thus, MN represent a valuable tool for further investigation of the pathomechanism after VX exposure. These findings might set the course for the development of a promising human neuromuscular test model and patient-specific therapies in the future.

Highly specific and sensitive chromo-fluorogenic detection of sarin, tabun, and mustard gas stimulants: a multianalyte recognition approach.

Nerve agents are the most notorious substances, which can be fatal to an individual because they block the activity of acetylcholinesterase. Fighting against unpredictable terrorist assaults and wars requires the simple and quick detection of chemical warfare agent vapor. In the present contribution, we have introduced a rhodamine-based chemosensor, BDHA, for the detection of nerve gas-mimicking agents diethylchlorophosphate (DCP) and diethylcyanophosphonate (DCNP) and mustard gas-mimicking agent 2-chloroethyl ethyl sulfide (CEES), both in the liquid and vapor phase. Probe BDHA provides the ability for detection by the naked eye in terms of colorimetric and fluorometric changes. It has been revealed that the interaction between nerve agents mimics and probe BDHA facilitates spirolactam ring opening due to the phosphorylation process. Thus, the highly fluorescent and colored species developed while probe BDHA is colorless and non-fluorescent due to the intramolecular spirolactam ring. Moreover, probe BDHA can effectively recognize DCP, DCNP, and CEES in the µM range despite many toxic analytes and could be identified based on the response times and quantum yield values. Inexpensive, easily carried paper strips-based test kits were developed for the quick, on-location solid and vapor phase detection of these mustard gas imitating agents (CEES) and nerve gas mimicking agents (DCP and DCNP) without needing expensive equipment or skilled personnel. More remarkably, the test strips' color and fluorescence can be rapidly restored, exposing them to triethyl amine (TEA) for cyclic use, suggesting a potential application in the real-time identification of chemical warfare agents. To accomplish the on-location application of BDHA, we have experimented with soil samples to find traces of DCP. Therefore, the chromo-fluorogenic probe BDHA is a promising, instantaneous, and on-the-spot monitoring tool for the selective detection of DCP, DCNP, and CEES in the presence of others.

No-observed-adverse-effect-level (NOAEL) assessment as an optimized dose of cholinesterase reactivators for the treatment of exposure to warfare nerve agents in mice.

Despite the international convention on the prohibition of chemical weapons ratified in 1997, the threat of conflicts and terrorist attacks involving such weapons still exists. Among these, organophosphorus-nerve agents (OPs) inhibit cholinesterases (ChE) causing cholinergic syndrome. The reactivation of these enzymes is therefore essential to protect the poisoned people. However, these reactivating molecules, mainly named oximes, have major drawbacks with limited efficacy against some OPs and a non-negligible ChE inhibitor potential if administered at an inadequate dose, an effect that they are precisely supposed to mitigate. As a result, this project focused on assessing therapeutic efficacy, in mice, up to the NOAEL dose, the maximum dose of oxime that does not induce any observable toxic effect. NOAEL doses of HI-6 DMS, a reference oxime, and JDS364. HCl, a candidate reactivator, were assessed using dual-chamber plethysmography, with respiratory ventilation impairment as a toxicity criterion. Time-course modeling parameters and pharmacodynamic profiles, reflecting the interaction between the oxime and circulating ChE, were evaluated for treatments at their NOAEL and higher doses. Finally, the therapeutic potential against OPs poisoning was determined through the assessment of protective indices. For JDS364. HCl, the NOAEL dose corresponds to the smallest dose inducing the most significant therapeutic effect without causing any abnormality in ChE activity. In contrast, for HI-6 DMS, its therapeutic benefit was observed at doses higher than its NOAEL, leading to alterations in respiratory function. These alterations could not be directly correlated with ChE inhibition and had no adverse effects on survival. They are potentially attributed to the stimulation of non-enzymatic cholinergic targets by HI-6 DMS. Thus, the NOAEL appears to be an optimal dose for evaluating the efficacy of oximes, particularly when it can be linked to respiratory alterations effectively resulting from ChE inhibition.

Recent advances in sensing toxic nerve agents through DMMP model simulant using diverse nanomaterials-based chemical sensors.

Recent terrorist assaults have demonstrated the need for the exploration and design of sustainable and stable chemical sensors with quick reaction times combined with great sensitivity. Among several classes of chemical warfare agents, nerve agents have been proven to be the most hazardous. Even short-term exposure to them can result in severe toxic effects. Human beings inadvertently face the after-effects of these chemicals even several years after these chemicals were used. Due to the extreme toxicity and difficulty in handling, dimethyl methylphosphonate (DMMP), a simulant of nerve agents with much lesser toxicity, is frequently used in laboratories as a substitute. Having a chemical structure almost identical to those of nerve agents, DMMP can mimic the properties of nerve agents. Through this paper, authors have attempted to introduce the evolution of several chemical sensors used to detect DMMP in recent years, including field-effect transistors, chemicapacitors, chemiresistors, and mass-sensitive sensors. A detailed discussion of the role of nanomaterials as chemical sensors in the detection of DMMP has been the main focus of the work through a comprehensive overview of the research on gas sensors that have been reported making use of the properties of a wide range of nanomaterials.

Powders to Thin Films: Advances in Conjugated Microporous Polymer Chemical Sensors.

Chemical sensing of harmful species released either from natural or anthropogenic activities is critical to ensuring human safety and health. Over the last decade, conjugated microporous polymers (CMPs) have been proven to be potential sensor materials with the possibility of realizing sensing devices for practical applications. CMPs found to be unique among other porous materials such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) due to their high chemical/thermal stability, high surface area, microporosity, efficient host-guest interactions with the analyte, efficient exciton migration along the π-conjugated chains, and tailorable structure to target specific analytes. Several CMP-based optical, electrochemical, colorimetric, and ratiometric sensors with excellent selectivity and sensing performance were reported. This review comprehensively discusses the advances in CMP chemical sensors (powders and thin films) in the detection of nitroaromatic explosives, chemical warfare agents, anions, metal ions, biomolecules, iodine, and volatile organic compounds (VOCs), with simultaneous delineation of design strategy principles guiding the selectivity and sensitivity of CMP. Preceding this, various photophysical mechanisms responsible for chemical sensing are discussed in detail for convenience. Finally, future challenges to be addressed in the field of CMP chemical sensors are discussed.

The prediction of hydrolysis and biodegradation of organophosphorus-based chemical warfare agents (G-series and V-series) using toxicology in silico methods.

Nerve agents (G- and V-series) are a group of extremely toxic organophosphorus chemical warfare agents that we have had the opportunity to encounter many times on a massive scale (Matsumoto City, Tokyo subway and Gulf War). The threat of using nerve agents in terrorist attacks or military operations is still present, even with establishing the Chemical Weapons Convention as the legal framework. Understanding their environmental sustainability and health risks is critical to social security. Due to the risk of contact with dangerous nerve agents and animal welfare considerations, in silico methods were used to assess hydrolysis and biodegradation safely. The environmental fate of the examined nerve agents was elucidated using QSAR models. The results indicate that the investigated compounds released into the environment hydrolyse at a different rate, from extremely fast (<1 day) to very slow (over a year); V-agents undergo slower hydrolysis compared to G-agents. V-agents turned out to be relatively challenging to biodegrade, the ultimate biodegradation time frame of which was predicted as weeks to months, while for G-agents, the overwhelming majority was classified as weeks. In silico methods for predicting various parameters are critical to preparing for the forthcoming application of nerve agents.