Nitric Oxide Gas Research Articles

Molecular dissociation of nitric oxide (NO) on VO2(010) surface : A DFT study including vdW forces

The adsorption and coadsorption of O and N atomic species, as well as the dissociation of NO molecule on VO2(010) surface have been studied using the density functional theory (DFT) with GGA-PBE as the exchange–correlation, including van der Waals (vdW) corrections of the form PBE+vdW-DF2. We found that the short-bridge (sb) site is the energetically most stable for both N and O atoms. The inclusion of PBE+vdW-DF2 corrections does not change the preferred adsorption site, however it reduces the value of the adsorption energy relative to ordinary GGA-PBE functional. Also, while the GGA-PBE functional results in finite magnetization on the O and N atoms when adsorbed on the VO2 surface, the inclusion of the vdW forces results in zero magnetization of the atoms. In addition, our Löwdin charge transfer analysis shows electron transfer from the VO2(010) surface to the O atom, which is further supported by an accumulation of charge density around the O atom as well as the charge depletion from the V surface atoms. At a lower coverage θ= 0.25 ML, the N atom behaves like a charge acceptor, that is, electrons are transferred from the VO2 surface to it. At a higher coverage θ= 0.50 ML and 0.75 ML, the N atom behaves like a charge donor, i.e., there is a transfer of electronic charges to the VO2 surface. We emphasize that charge transfer between the adsorbate (O and N) and the surface establishes adsorbate-surface bonding which enhances the stability of the adsorbate. Furthermore, our nudged elastic band calculations (NEB) for determining the minimum energy path (MEP) and activation barrier energy (Ea) for NO dissociation into N and O atoms show Ea= 2.18 eV (1.78 eV) as obtained using the GGA-PBE (PBE+vdW-DF2) functionals. Regarding potential application, this study thus contributes to reducing the amount and harmful effect of NO gas in the atmosphere.

Self-Sulfhydrated, Nitro-Fixed Albumin Nanoparticles as a Potent Therapeutic Agent for the Treatment of Acute Liver Injury.

Exogenous polysulfhydryls (R-SH) supplementation and nitric oxide (NO) gas molecules delivery provide essential antioxidant buffering pool components and anti-inflammatory species in cellular defense against injury, respectively. Herein, the intermolecular disulfide bonds in bovine serum albumin (BSA) molecules were reductively cleaved under native and mild conditions to expose multiple sulfhydryl groups (BSA-SH), then sulfhydryl-nitrosylated (R-SNO), and nanoprecipitated to form injectable self-sulfhydrated, nitro-fixed albumin nanoparticles (BSA-SNO NPs), allowing albumin to act as a NO donor reservoir and multiple sulfhydryl group transporter while also preventing unfavorable oxidation and self-cross-linking of polysulfhydryl groups. In two mouse models of ischemia/reperfusion-induced and endotoxin-induced acute liver injury (ALI), a single low dosage of BSA-SNO NPs (S-nitrosothiols: 4 μmol·kg-1) effectively attenuated oxidative stress and systemic inflammation cascades in the upstream pathophysiology of disease progression, thus rescuing dying hepatocytes, regulating host defense, repairing microcirculation, and restoring liver function. By mechanistically upregulating the antioxidative signaling pathway (Nrf-2/HO-1/NOQ1) and inhibiting the inflammatory cytokine storm (NF-κB/p-IκBα/TNF-α/IL-β), BSA-SNO NPs blocked the initiation of the mitochondrial apoptotic signaling pathway (Cyto C/Bcl-2 family/caspase-3) and downregulated the cell pyroptosis pathway (NLRP3/ASC/IL-1β), resulting in an increased survival rate from 26.7 to 73.3%. This self-sulfhydrated, nitro-fixed functionalized BSA nanoformulation proposes a potential drug-free treatment strategy for ALI.

Multifunctional Molecular Hybrids Photoreleasing Nitric Oxide: Advantages, Pitfalls, and Opportunities.

The multifaceted role nitric oxide (NO) plays in human physiology and pathophysiology has opened new scenarios in biomedicine by exploiting this free radical as an unconventional therapeutic against important diseases. The difficulties in handling gaseous NO and the strict dependence of the biological effects on its doses and location have made the light-activated NO precursors, namely NO photodonors (NOPDs), very appealing by virtue of their precise spatiotemporal control of NO delivery. The covalent integration of NOPDs and additional functional components within the same molecular skeleton through suitable linkers can lead to an intriguing class of multifunctional photoactivatable molecular hybrids. In this Perspective, we provide an overview of the recent advances in these molecular constructs, emphasizing those merging NO photorelease with targeting, fluorescent reporting, and phototherapeutic functionalities. We will highlight the rational design behind synthesizing these molecular hybrids and critically describe the advantages, drawbacks, and opportunities they offer in biomedical research.

Application of Floating Beds Constructed with Woodchips for Nitrate Removal and Plant Growth in Wetlands

Constructed wetlands and constructed floating wetlands are widely used for nitrogen (N) removal from surface water to combat eutrophication in freshwaters. Two main N removal pathways in freshwaters are plant biomass N uptake and denitrification, i.e. transformation of nitrate (NO3-) to nitrous oxide (N2O) or nitrogen gas (N2) by different microbes possessing nirK, nirS, nosZI, and nosZII genes. In this study, we tested woodchips-based floating beds (WFBs) as a nature-based and environment-friendly method to remove nitrate-nitrogen (NO3-N) from water. Moreover, we tested whether WFBs could support the growth of three selected plant species and the abundance of microbes on plant roots and woodchips as a proxy for WFBs’ denitrification potential. We conducted a greenhouse experiment for 90 days and measured NO3-N removal rates from water in WFBs mesocosms during five sampling occasions. Plant biomass production, biomass N uptake, and plant morphology related to N uptake and abundance of denitrifying organisms were measured at the end of the experiment. NO3-N removal rates were 29.17 ± 11.07, 28.18 ± 12.62, 25.28 ± 9.90, and 22.16 ± 7.79 mg L–1 d–1 m–2 (mean ± standard deviation) in Glyceria maxima, Juncus effusus, Filipendula ulmaria, and unplanted WFBs treatments, respectively for whole experimental period. N content in above- and belowground biomass of studied species ranged between 0.98 – 1.15 and 1.09 – 1.28 (% dry weight), respectively. Plant relative biomass production was 215 ± 61, 67 ± 18, and 7 ± 17 (% dry weight) for G. maxima, J. effusus and F. ulmaria, respectively. Denitrifiers were detected both on plant roots and woodchips, indicating WFBs’ denitrification potential. Our study highlights that WFBs could be applied to enhance NO3-N removal from surface water through plant biomass uptake and denitrification processes. Future studies should consider the long-term in situ application of WFBs for NO3-N removal from water.

Lesion durability found during mandated percutaneous catheter ablation after surgical cryo-ablation for treatment of non-paroxysmal atrial fibrillation

ObjectivesCurrent recommendations support surgical treatment of atrial fibrillation (AF) in patients indicated for cardiac surgery. These procedures are referred to as concomitant and may be carried out using radiofrequency energy or cryo-ablation. This study aimed to assess the electrophysiological findings in patients undergoing concomitant cryo-ablation.MethodsPatients with non-paroxysmal AF undergoing coronary artery bypass grafting and/or valve repair/replacement were included in the trial if concomitant cryo-ablation was part of the treatment plan according to current guidelines. The patients reported in this study were assigned to undergo staged percutaneous radiofrequency catheter ablation (PRFCA), i.e., hybrid treatment, as a part of the SURHYB trial protocol.ResultsWe analyzed 103 patients who underwent PRFCA 105 ± 35 days after surgery. Left and right pulmonary veins (PVs) were found isolated in 65 (63.1%) and 63 (61.2%) patients, respectively. The LA posterior wall isolation and mitral isthmus conduction block were found in 38 (36.9%) and 18 (20.0%) patients, respectively. Electrical reconnections (gaps) in the left PVs were more often localized superiorly than inferiorly (57.9% vs. 26.3%, P = 0.005) and anteriorly than posteriorly (65.8% vs. 31.6%, P = 0.003). Gaps in the right PVs were more equally distributed anteroposteriorly but dominated in superior segments (72.5% vs. 40.0%, P = 0.003). There was a higher number of gaps on the roof line compared to the inferior line (131 (67.2%) vs. 67 (42.2%), P < 0.001). Compared to epicardial cryo-ablation, endocardial was more effective in creating PVs and LA posterior wall isolation (P < 0.05). Cryo-ablation using nitrous oxide (N20) or argon (Ar) gas as cooling agents was similarly effective (P = NS).ConclusionsThe effectiveness of surgical cryo-ablation in achieving transmural and durable lesions in the left atrium is surprisingly low. Gaps are located predominantly in the superior and anterior portions of the PVs and on the roof line. Endocardial cryo-ablation is more effective than epicardial ablation, irrespective of the cooling agent used.

Nitric oxide in oncology: a two-faced Janus

Nitric oxide (NO) plays a significant role in the development of tumor processes, offering potential therapeutic options and serving as a target for influencing tumor growth.The aim of this review was to study the role of nitric oxide in the development of cancer, identify key signaling pathways in which NO is involved, mechanisms and methods of nitric oxide delivery in tumor therapy, as well as its impact as a therapeutic target.Results. Different isoforms of nitric oxide synthase (NOS) regulate nervous functions, vascular functions, and inflammatory processes. Elevated levels of induced nitric oxide synthase (iNOS) are associated with tumor development, and its inhibitors can suppress tumor growth. Research indicates that the effect of NO on tumors depends on the concentration and duration of exposure. Low concentrations stimulate the growth and metastases of tumor cells, whereas high concentrations exert an anti-tumor effect, enhancing therapy sensitivity. NO also impacts angiogenesis, metastases, and immune response. The application of NO in tumor treatment is challenging due to its short half-life and rapid diffusion. Developing various NO delivery methods, like gaseous NO and nanoparticles, holds promise for improving the effectiveness and control of distribution. Silicon and goldbased nanoparticles demonstrate potential for NO delivery, enhancing immune response and showing synergism with chemotherapy. Inhibitors of iNOS suppress tumor growth. Their combined usage with other agents, such as chemotherapy, displays promising results in tumor growth control. Further research and clinical trials are essential to determine optimal conditions for employing NO and iNOS inhibitors in cancer treatment. Overall, studying the influence of NO and iNOS on tumor processes represents a crucial area for developing novel treatment methods, underscoring the therapeutic potential of these molecules as agents and targets to enhance oncological outcomes.Conclusion. Nitric oxide and various isoforms of NOS, in particular induced NOS, play a vital role in the regulation of oncological processes. Research confirms the promise of nitric oxide in oncology as a potential antitumor agent. The use of iNOS inhibitors shows potential in controlling tumor growth, especially when combined with other drugs such as chemotherapy. In addition, the development of NO delivery methods is an area of active research that may improve the efficiency of NO distribution in the body and tumor.

The influence of exogenous and endogenous nitric oxide on the human and animal body

It has been shown that the inhalation of gaseous NO (exogenous nitric oxide) leads to the formation of nitrosonium cations (NO+) in the circulating blood of humans and animals during the oxidation of NO, which can have a detrimental effect on pathogenic viruses and bacteria. When thiols enter the blood simultaneously with NO inhalation, they form S-nitrosothiols with NO+ and cause hypotensive effect in animals. The biological effect of endogenous NO, which is produced in cells and tissues with the participation of NO synthases in animals and humans, is mediated by the dinitrosyl iron complexes (DNIC) formed with thiol-containing ligands. As NO and NO+ donors, these complexes have a variety of regulatory and cytotoxic effects on the animal and human body. In particular, the NO+ released by DNIC was shown to suppress SARS-CoV-2 infection in Syrian hamsters.

The influence of various technologies for the use of gaseous nitric oxide on the functional and morphological state of the lungs, markers of myocardial damage and clinical outcomes in cardiosurgical interventions with cardiopulmonary bypass

The aim of the study was to evaluate the impact of various technologies for the use of gaseous nitric oxide on the state of the lungs and heart during heart valve surgery under cardiopulmonary bypass (CPB).Methods. The study included 93 patients of both sexes. All patients underwent heart valve surgery and combined surgical interventions under CPB. The patients were divided into 4 groups. Group 1 (control, n = 30) used the standard protocol for anesthetic and perfusion management. Group 2 (n = 30) received inhalation of nitric oxide (20 ppm) within 3 days before surgery, as well as before and after CPB. Group 3 (n = 30) inhaled nitric oxide (40 ppm) throughout surgery with the medication delivered through inspiratory part of the ventilator and combined with perfusion of the pulmonary artery and reduced volume ventilation during CPB. Group 4 (n = 33) received nitric oxide (40 ppm) via oxygenator of the heart-lung machine. We assessed changes in the functional parameters of the lungs at different phases of surgery, performed a morphological examination of the lungs in the initial phase (before CPB), at the peak of ischemia, and after reperfusion. The state of the myocardium after surgery was assessed by troponin I (cTnI) activity at the beginning of the operation, after transfer to the ICU, at 12, 24 and 48 hours after the surgery. Myocardial damage index (MDI) was calculated according to the following formula: MDI = TnIlate / TnIearly. The clinical outcomes of the surgeries were evaluated.Results. There were no statistically significant differences in the functional state of the lungs with various options for inhalation delivery and administration via the CPB circuit. The most intact indicators of the functional state of the lungs were seen in patients of Group 3 who received inhaled nitric oxide throughout surgery and combined mechanical ventilation with the addition of nitric oxide and perfusion of the pulmonary artery during CPB. Morphological examination of the lungs showed that inhalation of nitric oxide before CPB does not prevent the development of morphological disorders. Morphological changes found in Group 3 were the smallest. The supply of nitric oxide into the CPB circuit statistically significantly improved the restoration of pulmonary blood flow during reperfusion. The cTnI level statistically significantly increased in all groups of patients, however, it was statistically significantly lower in Groups 2, 3, and 4 compared with Group 1 at the end of surgery, in Groups 3 and 4 compared with Groups 1 and 2 after 12 and 24 hours, and in Group 3 after 48 hours. The most favorable changes in the MDI were seen in Group 3; statistically significantly lower MDI was registered 12 and 48 hours after surgery in this group compared with Groups 1, 2, and 4. A lower complication rate, a shorter duration of ventilation and stay in the ICU were observed in Groups 3 and 4.Conclusion. Nitric oxide has a protective effect on the lungs and heart when used during anesthesia and cardiopulmonary bypass in heart valve surgery. It preserves the lung function and morphology and statistically significantly reduces cTnI level and myocardial damage index in the postoperative period. The extent of the protective effect depends on the nitric oxide exposure time and is most pronounced when nitric oxide is used throughout the surgery, including during CPB.

Hydroxylamine production by Alcaligenes faecalis challenges the paradigm of heterotrophic nitrification

Heterotrophic nitrifiers continue to be a hiatus in our understanding of the nitrogen cycle. Despite their discovery over 50 years ago, the physiology and environmental role of this enigmatic group remain elusive. The current theory is that heterotrophic nitrifiers are capable of converting ammonia to hydroxylamine, nitrite, nitric oxide, nitrous oxide, and dinitrogen gas via the subsequent actions of nitrification and denitrification. In addition, it was recently suggested that dinitrogen gas may be formed directly from ammonium. Here, we combine complementary high-resolution gas profiles, 15 N isotope labeling studies, and transcriptomics data to show that hydroxylamine is the major product of nitrification in Alcaligenes faecalis . We demonstrated that denitrification and direct ammonium oxidation to dinitrogen gas did not occur under the conditions tested. Our results indicate that A. faecalis is capable of hydroxylamine production from an organic intermediate. These results fundamentally change our understanding of heterotrophic nitrification and have important implications for its biotechnological application.

Nitrogen Removal Performance and Microbial Community Structure of IMTA Ponds (Apostistius japonicus-Penaeus japonicus-Ulva)

Denitrification and anaerobic ammonium oxidation (anammox) are key processes for nitrogen removal in aquaculture, reducing the accumulated nitrogen nutrients to nitrogen gas or nitrous oxide gas. Complete removal of nitrogen from aquaculture systems is an important measure to solve environmental pollution. In order to evaluate the nitrogen removal potential of marine aquaculture ponds, this study investigated the denitrification and anammox rates, the flux of nitrous oxide (N2O) at the water–air interface, the sediment microbial community structure, and the gene expression associated with the nitrogen removal process in integrated multi-trophic aquaculture (IMTA) ponds (Apostistius japonicus-Penaeus japonicus-Ulva) with different culture periods. The results showed that the denitrification and anammox rates in sediments increased with the increase of cultivation periods and depth, and there was no significant difference in nitrous oxide gas flux at the water–air interface between different cultivation periods (p > 0.05). At the genus and phylum levels, the abundance of microorganisms related to nitrogen removal reactions in sediments changed significantly with the increase of cultivation period and depth, and was most significantly affected by the concentration of particulate organic nitrogen (PON) in sediments. The expression of denitrification gene (narG, nirS, nosZ) in surface sediments was significantly higher than that in deep sediments (p < 0.05), and was negatively correlated with denitrification rate. All samples had a certain anammox capacity, but no known anammox bacteria were found in the microbial diversity detection, and the expression of gene (hzsB) related to the anammox process was extremely low, which may indicate the existence of an unknown anammox bacterium. The data of this study showed that the IMTA culture pond had a certain potential for nitrogen removal, and whether it could make a contribution to reducing the pollution of culture wastewater still needed additional practice and evaluation, and also provided a theoretical basis for the nitrogen removal research of coastal mariculture ponds.Graphical

Exodontia of third molars in a single surgery using conscious sedation in an anxious patient: case report

The conscious sedation performed by inhaling nitrous oxide gas (N2O) associated with oxygen gas (O2) provides an ideal analgesic and anxiolytic effect for patients who are insecure and anxious to undergo dental procedures. The aim of the present study is to report a clinical case of a single surgery to extract teeth 18, 28, 38, and 48 in an odontophobic patient who undergoes anxiety by using conscious sedation through the inhalation of nitrous oxide gas diluted in oxygen gas. The patient achieved a state of deep relaxation during sedation, with a decrease in his initial heart rate, high oxygen saturation, and low intraoperative bleeding. The authors concluded that conscious sedation using nitrous oxide is an important ally in oral surgeries for anxious patients.

Cheerfulness in the history of psychiatry.

In 1762, Louis-Antoine Marquis de Caraccioli (1719-1803), a prolific writer of the eighteenth century, dedicated a book to a psychological theme that medicine has forgotten: 'gaité' in French, which we will translate as 'cheerfulness'. At the beginning of the nineteenth century, this work inspired two doctoral theses in medicine, one defended in Montpellier, the other in Paris. In their texts, Louis Monferran (1785-?) and Vincent Rémi Giganon (1794-1857) explored the therapeutic benefits of the medical prescription of cheerfulness. In addition to lifestyle recommendations, they focused on the psychotropic substances available to them: alcohol, coca, hemp and opiates. In an original and novel way, Giganon introduced and recommended 'le gaz oxydule d'azote inspiré', or inhaled nitrous oxide gas.

Mechanisms and recent advances in the diagnosis and treatment of nitrous oxide-induced peripheral neuropathy: a narrative review

Under standard conditions, nitrous oxide (N2O) manifests as a colorless, odorless gas with a mildly sweet taste. The compound finds applications in various fields, including its use as an aerosol propellants, an accelerant in motor racing, and an anesthetic in surgical procedures and dentistry. Unfortunately, the recreational misuse of N2O has become prevalent among young individuals due to its euphoric and hallucinogenic effects. Compounding this issue is the fact that nitrous oxide can be easily obtained from over-the-counter household items, facilitating its non-medical use. The global community has witnessed a surge in the recreational utilization of nitrous oxide gas in recent years. Despite the widespread non-medical abuse of N2O, there remains inadequate understanding of the potential adverse effects resulting from exposure to it. This paper provides an overview of management findings, laboratory and electrodiagnostic characteristics, as well as clinical presentations associated with neurological disorders induced by nitrous oxide usage.

Rock Phosphate and Biochar Effects on Greenhouse Gas Emissions and Soil Fertility in Southern Alberta Potato Field

The application of biochar soil amendment and rock phosphate fertilizer to the soil could lead to achieving net zero emissions and food security; however, the effectiveness of using biochar and rock phosphate in southern Alberta brown chernozemic soil is not yet assessed. In the first trial of this study, varying levels of urea (N), with varying levels of biochar (B) were applied. The same level of rock phosphate (RP) and triple super phosphate (TSP) were applied to compare efficiency of the two fertilizers. The second trial involved applying the same nutrients, but with higher levels than the first trial. The results indicated that the fertilizer application rates did not affect the growth and yield of potatoes because of the application rates of the fertilizer and fertility status of the soil, whereas in the second trial, TSP and RP treatments had the same growth and yield. Furthermore, the high application rate of nitrogen fertilizer and RP with or without biochar in the potato plot emitted high nitrous oxide gas emissions while the low application rate of nitrogen fertilizer and RP kept the carbon dioxide in the soil. Nevertheless, in the second experiment, the application of biochar and rock phosphate reduced nitrous oxide and carbon dioxide emissions. We observed high residual nitrogen and manganese nutrients after harvest in the plot treated to rock phosphate and biochar. Therefore, rock phosphate and biochar have the potential to increase food production and mitigate climate change.

Adsorption of NO on ZnO monolayer doped with transition metal (Ti, V, Cr, Mn, Co, and Zr): The first-principles study

Nitric oxide (NO) is a harmful gas produced by fuel combustion in the petrochemical industry. In this paper, the gas sensitivity of NO molecule on ZnO monolayer (ZnO-ML) doped with transition metal (TM = Ti, V, Cr, Mn, Co, and Zr) is systematically investigated by the first-principles calculation. The results show that the adsorption mode of NO molecule on the doped system (TM-ZnO-ML) changes from physisorption to chemisorption, and adsorption energies range from −1.59 eV to −3.12 eV, which are 8–16 times the origin adsorption energy (−0.19 eV) on the pristine ZnO-ML. Meanwhile, the charge transfer between NO molecule and substrates increases by 4–13 times compared with the pristine ZnO-ML. Furthermore, under the applied electric field of −0.4 V/Å, the charges transferred from V-ZnO-ML to the NO increase to 0.54 e. All of the results reveal the broad application prospect of TM-ZnO-ML in NO gas sensors.

Enhanced breast cancer treatment using phototherapy and RNS therapy with macrophage membrane-coated liposomes

Breast cancer, the predominant malignancy afflicting women, continues to pose formidable challenges despite advancements in therapeutic interventions. This study elucidates the potential of phototherapy, comprising both photothermal and photodynamic therapy (PTT/PDT), as a novel and promising modality. To achieve this goal, we devised liposomes coated with macrophage cell membranes including macrophage-associated membrane proteins, which have demonstrated promise in biomimetic delivery systems for targeting tumors while preserving their inherent tumor-homing capabilities. This integrated biomimetic delivery system comprised IR780, NONOate, and perfluorocarbon. This strategic encapsulation aims to achieve a synergistic combination of photodynamic therapy (PDT) and reactive nitrogen species (RNS) therapy. Under near-infrared laser irradiation at 808 nm, IR780 demonstrates its ability to prolifically generate reactive oxygen species (ROS), including superoxide anion (O2•−), singlet oxygen, and hydroxyl radical (·OH). Simultaneously, NONOate releases nitric oxide (NO) gas upon the same laser irradiation, thereby engaging with IR780-induced ROS to facilitate the formation of peroxynitrite anion (ONOO−), ultimately inducing programmed cell death in cancer cells. Additionally, the perfluorocarbon component of our delivery system exhibits a notable affinity for oxygen and demonstrates efficient oxygen-carrying capabilities. Our results demonstrate that IR780-NO-PFH-Lip@M significantly enhances breast cancer cell toxicity, reducing proliferation and in vivo tumor growth through simultaneous heat, ROS, and RNS production. This study contributes valuable insights to the ongoing discourse on innovative strategies for advancing cancer therapeutics.

NIR-activated electrospun nanodetonator dressing enhances infected diabetic wound healing with combined photothermal and nitric oxide-based gas therapy

Diabetic wounds pose a challenge to healing due to increased bacterial susceptibility and poor vascularization. Effective healing requires simultaneous bacterial and biofilm elimination and angiogenesis stimulation. In this study, we incorporated polyaniline (PANI) and S-Nitrosoglutathione (GSNO) into a polyvinyl alcohol, chitosan, and hydroxypropyltrimethyl ammonium chloride chitosan (PVA/CS/HTCC) matrix, creating a versatile wound dressing membrane through electrospinning. The dressing combines the advantages of photothermal antibacterial therapy and nitric oxide gas therapy, exhibiting enduring and effective bactericidal activity and biofilm disruption against methicillin-sensitive Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Escherichia coli. Furthermore, the membrane’s PTT effect and NO release exhibit significant synergistic activation, enabling a nanodetonator-like burst release of NO through NIR irradiation to disintegrate biofilms. Importantly, the nanofiber sustained a uniform release of nitric oxide, thereby catalyzing angiogenesis and advancing cellular migration. Ultimately, the employment of this membrane dressing culminated in the efficacious amelioration of diabetic-infected wounds in Sprague–Dawley rats, achieving wound closure within a concise duration of 14 days. Upon applying NIR irradiation to the PVA-CS-HTCC-PANI-GSNO nanofiber membrane, it swiftly eradicates bacteria and biofilm within 5 min, enhancing its inherent antibacterial and anti-biofilm properties through the powerful synergistic action of PTT and NO therapy. It also promotes angiogenesis, exhibits excellent biocompatibility, and is easy to use, highlighting its potential in treating diabetic wounds.Graphical

Platelet Membrane Coated Cu9S8-SNAP for Targeting NIR-II Mild Photothermal Enhanced Chemodynamic/Gas Therapy of Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is a highly aggressive and uncommon subtype of breast cancer with a poor prognosis. It is crucial to prioritise the creation of a nanotherapeutic method that is highly selective and actively targeting TNBC. This study explores a new nanosystem, Cu9S8-SNAP@PM (C-S@P), composed of Cu9S8-SNAP coated with a platelet membrane (PM). The purpose of this nanosystem is to cure TNBC using multimodal therapy. The utilisation of PM-coated nanoparticles (NPs) enables active targeting, leading to the efficient accumulation of C-S@P within the tumour. The Cu9S8 component within these NPs serves the potential to exert photothermal therapy (PTT) and chemodynamic therapy (CDT). Simultaneously, the S-Nitroso-N-Acetylvanicillamine (SNAP) component enables nitric oxide (NO) gas therapy (GT). Furthermore, when exposed to NIR-II laser light, Cu9S8 not only increases the temperature of the tumour area for PTT, but also boosts CDT and stimulates the release of NO through thermal reactions to improve the effectiveness of GT. Both in vitro and in vivo experimental results validate that C-S@P exhibits minimal side effects and represents a multifunctional nano-drug targeted at tumors for efficient treatment. This approach promises significant potential for TNBC therapy and broader applications in oncology.

PH-sensitive release of nitric oxide gas using peptide-graphene co-assembled hybrid nanosheets

Nitric oxide (NO) donating drugs such as organic nitrates have been used to treat cardiovascular diseases for more than a century. These donors primarily produce NO systemically. It is however sometimes desirable to control the amount, location, and time of NO delivery. We present the design of a novel pH-sensitive NO release system that is achieved by the synthesis of dipeptide diphenylalanine (FF) and graphene oxide (GO) co-assembled hybrid nanosheets (termed as FF@GO) through weak molecular interactions. These hybrid nanosheets were characterised by using X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, zeta potential measurements, X-ray photoelectron spectroscopy, scanning and transmission electron microscopies. The weak molecular interactions, which include electrostatic, hydrogen bonding and π-π stacking, are pH sensitive due to the presence of carboxylic acid and amine functionalities on GO and the dipeptide building blocks. Herein, we demonstrate that this formulation can be loaded with NO gas with the dipeptide acting as an arresting agent to inhibit NO burst release at neutral pH; however, at acidic pH it is capable of releasing NO at the rate of up to 0.6 μM per minute, comparable to the amount of NO produced by healthy endothelium. In conclusion, the innovative conjugation of dipeptide with graphene can store and release NO gas under physiologically relevant concentrations in a pH-responsive manner. pH responsive NO-releasing organic-inorganic nanohybrids may prove useful for the treatment of cardiovascular diseases and other pathologies.

A calibration methodology for the novel radioluminescence detector systems

Radioluminescence mapping using well-characterized and optimized optical systems is an effective method for localizing contamination with alpha-emitting radionuclides. To apply this novel approach to radiological emergency management, nuclear safeguards, nuclear decommissioning, and nuclear forensics, an established traceability chain is required. This work presents the development and implementation of a novel calibration methodology to provide valuable information about, and confidence in, the performance of radioluminescence detection systems. The proposed calibration methodology is based on two complementary approaches: (a) application of well-characterized activity standards to establish a traceable relationship between radioluminescence intensity and alpha activity, and (b) use of all optical radiation-based devices that, when calibrated against an alpha activity standard, simulate the radioluminescence induced in nitrogen (N2) and nitric oxide (NO) gases by alpha particles in specific spectral regions. A dedicated 210Po alpha activity standard with a narrow peak of less than 32keV FWHM at 5.3MeV has been developed and used to characterize a lens-based radioluminescence detection system in terms of its sensitivity to alpha-induced radioluminescence in different atmospheres (air, N2, N2 ＋ NO mixture) in the UV-A and UV-C (solar blind) spectral regions. The characterized lens system was then used as an intermediary transfer device to cross-calibrate two portable integrating sphere-based radiance standards designed to simulate radioluminescence in the UV-A and UV-C spectral regions. Both radiance standards can be used as transfer standards simulating up to 510MBq when used in the UV-A and up to 8.7GBq when used in the UV-C spectral regions. They substantially simplify routine quality control of radioluminescence detection systems by eliminating the need for open alpha sources, which are always associated with strict radiation safety precautions. Furthermore, since radiance standards can operate in a wide range of intensities, linearity and detection limits of radioluminescence detectors can be readily determined. The design, construction, radiometric characterization, and calibration of dedicated transfer standards, as well as the development of new calibration procedures for radiometric traceability of radioluminescence detection systems, will enable appropriate accident and post-accident radiation measurements that will lead to more effective countermeasures and better protection of people, wildlife, and the environment.