Membrane Permeability Research Articles

9332 Breathless Struggle: Unraveling The Interplay Between DKA And Acute Respiratory Distress Syndrome

Abstract Disclosure: S. Zahra: None. R. Subramani: None. M. Abbas: None. K.Y. Hasan: None. F. Manas: None. C. Bajracharya: None. Introduction: Diabetic Ketoacidosis (DKA) is a life threatening emergency with mortality rate of 0.15%-0.30%. Acute Respiratory Distress Syndrome (ARDS) is a rare complication of DKA which presents as a sudden onset of dyspnea and progressive hypoxia. It is an inflammatory process that damages the alveolar-capillary membrane leading to the fluid leakage into the alveolar space. The incidence of ARDS in DKA remains unknown. It is more commonly seen in adolescents and young adults. The exact pathogenesis of ARDS in DKA is currently unknown. Some proposed mechanisms are that a severe metabolic acidosis in DKA along with increased cytokines production due to long standing hyperglycemia leads to increased capillary membrane permeability allowing fluid to accumulate in the alveolar space. TNF-a and IL-6 along with other pro-inflammatory cytokines are known to cause endothelial damage and increase pulmonary permeability leading to pulmonary edema. However most DKA patients with severe metabolic acidosis do not develop ARDS. Case Presentation:Case 1: A 19 year old male with uncontrolled type I diabetes mellitus presented with altered mental status. On examination, he was tachycardic and tachypneic with dry mucous membranes. Lab workup revealed leukocytosis, severe hyperglycemia, and severe anion gap metabolic acidosis with beta hydroxybutyrate level of 14.20 mmol/L (normal: 0.02-0.27 mmol/L). He was diagnosed with DKA and started on intravenous fluids, and insulin as per institutional DKA protocol. Approximately 12 hours post-admission, the patient experienced sudden-onset dyspnea with deteriorating hypoxia, necessitating emergent intubation and mechanical ventilation. Chest radiography displayed bilateral patchy ground-glass opacifications consistent with acute respiratory distress syndrome (ARDS). Despite the administration of 8 liters of intravenous fluids, the patient exhibited a negative net fluid balance of 2.3 liters, implicating fluid shift. Further investigations, including bronchoscopy and bronchoalveolar lavage, revealed an unobstructed airway, minimal secretions, and no evidence of hemorrhage or infection. Comprehensive infectious work-ups yielded negative results as well, reinforcing the diagnosis of DKA as the underlying cause of ARDS. Conclusion: Acute Respiratory Distress Syndrome is a rare but potentially fatal complication of Diabetic Ketoacidosis. Early recognition of this serious pulmonary complication of DKA and its prompt management is essential to prevent respiratory failure and mortality. Presentation: 6/1/2024

Influence of lipid and metabolite profiles of mitochondrial fraction on pH and color stability of longissimus lumborum muscle with different ultimate beef pH

This study aimed to explore the differences in the lipidome and mitochondrial fraction metabolome of Nellore cattle meat in different ranges of ultimate pH (pHu) normal (≤5.79), intermediate (5.80 to 6.19) and high (≥ 6.20) after 3- and 21-d postmortem. Instrumental color, myoglobin redox state, oxygen consumption, and metmyoglobin-reducing activity were measured during storage. A total of 472 lipids and 22 mitochondrial fraction metabolites were identified. Beef with high pHu showed positive regulation of ceramides involved in apoptosis and negative regulation of lipid classes related to membrane permeability and stability. In addition, lower carnitine content was noted in high-pHu beef than in normal-pHu beef. Acylcarnitines, phosphatidylinositol, and IMP showed upregulation in beef with intermediate pHu, indicating changes mainly related to energy, purine and pyruvate metabolism. Aging time impacted on the lipid content and metabolites involved in different metabolic pathways. These results provided new insights into beef's mitochondrial fraction lipid and metabolic profile with different pHu. In addition, beef with intermediate pHu differs from beef with high pHu due to changes in energy metabolism.

Evaluation of inhibitory potential of the flavonoid-rich fraction of Myrica esculenta Buch.-Ham. ex D. Don against DSS-induced colonic inflammation in mice

ObjectiveMyrica esculenta (family Myricaceae), a valuable plant species in China and India, has been traditionally used by many tribes and local communities to manage gut disorders. Scientific validation of its anti-ulcerative colitis activity was aimed. MethodsThe ethyl acetate fraction of Myrica esculenta (MeEa) was prepared and evaluated for its potency against DSS-induced ulcerative colitis (UC) in mice at 200 and 400 mg/kg BW oral dose. The effective dose of MeEa was determined through its effect on DSS-induced UC and was further analyzed through its effects on disease activity index (DAI), colon length, colon weight/length ratio, spleen weight, serum and colon tissue cytokine level, cell count and hemoglobin content. Further, the effect was determined through histopathology and FITC-dextran-induced membrane permeability assay. ResultsBetween the two doses, MeEa at 400 mg/kg BW was found to be the most effective dose in terms of reduced DAI scores, protected colon length from shortening, decreased colon weight/length ratio, reduced spleen weight, decreased pro-inflammatory cytokine level and stabilized the anti-inflammatory cytokine level in serum and colon tissue. MeEa 400 reduced cell counts and increased hemoglobin content and platelet count. MeEa 400 also prevented the colon by protecting epithelial cells and crypts. MeEa 400 provided significant protection from intestinal leakage and reduced FITC dextran level in serum. DiscussionMeEa 400 possesses significant anti-inflammatory potential and acts via attenuation of DSS-induced UC and inhibition of DAI scores. It reduces pro-inflammatory cytokines and stabilizes anti-inflammatory cytokine levels, reduces cell count, and protects epithelial tissue and crypts in the colon, as well as intestinal membrane leakage that occurred due to FITC-dextran administration in mice.

Inhalable Advanced Co-Spray Dried Microparticles/Nanoparticles of a Novel RhoA/Rho Kinase Inhibitor with Lung Surfactant Biomimetic Phospholipids for Targeted Lung Delivery.

Co-spray dried inhalable powder formulations of fasudil monohydrochloride salt (FMCS) and inhalable lung surfactant-based nanocarriers composed of synthetic phospholipids, zwitterionic DPPC (1,2-palmitoyl-sn-glycero-3-phosphocholine) and anionic DPPG (1,2-dipalmitoyl-sn-glycero-3-[phosphor-rac-1-glycerol]) sodium salt, were designed and optimized using organic solution advanced spray drying. FMCS can potentially be used for the treatment of various complex pulmonary diseases with this current work focusing on pulmonary arterial hypertension. Comprehensive physicochemical characterization, electron and optical microscopy imaging, thermal analysis, molecular fingerprinting spectroscopy, in vitro aerosol dispersion performance with human dry powder inhaler (DPI) devices, in vitro membrane permeation and drug release, and in vitro human cellular studies were conducted. Well-defined, small, and smooth nanoparticles/microparticles in the solid state were engineered at different molar ratios of FMCS/DPPC/DPPG (25:75, 50:50, and 75:25) and successfully produced as inhalable powders having the properties necessary for targeted pulmonary delivery as dry powder inhalers. In vitro aerosol performance demonstrated excellent aerosol dispersion with different DPI devices. The phospholipid bilayer biophysical properties were confirmed and retained following cospray drying. Sustained release of fasudil drug and in vitro biocompatibility were demonstrated on human lung cells from different airway regions.

Lysosomal disruption, mitochondrial impairment, histopathological and oxidative stress in rat's nervous system after exposure to a neonicotinoid (imidacloprid).

Imidacloprid (IMI), a neonicotinoid pesticide, has been widely used due to its high efficiency against insect pests. However, its prolonged exposure may pose significant risks to non-target organisms, including mammals. Recent studies have raised concerns about its potential neurotoxicity, yet the underlying mechanisms remain poorly understood. This study aimed to assess the neurotoxic effects of chronic Imidacloprid exposure in Wistar rats, focusing on oxidative stress, mitochondrial dysfunction, and lysosomal disruption. Wistar rats were orally administered two doses of Imidacloprid (5mg/kg and 50mg/kg body weight) for three months. Neurotoxic effects were assessed by measuring key biochemical markers such as the enzymatic activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), and glutathione S-transferase (GST). Non-enzymatic markers, including glutathione (GSH) levels and malondialdehyde (MDA) index, were also evaluated. Mitochondrial function was assessed by analyzing oxygen consumption, swelling, and membrane permeability and histopathological changes. Lysosomal stability was examined using the Neutral Red Retention Time (NRRT) assay. Neutral red is a dye that accumulates in the acidic environment of lysosomes. Healthy lysosomes retain the dye, while compromised lysosomes lose it, indicating destabilization. By measuring the amount of neutral red retained in lysosomes, the NRRT assay assesses lysosomal integrity. Lysosomal pH variations were also monitored to evaluate functional changes. Microscopic analysis provided insight into structural changes in lysosomes and other cell components. Lysosomal destabilization was further confirmed by morphological alterations observed through light microscopy, revealing a progressive, time-dependent degeneration of lysosomal structures, including lysosomal expansion, neutral red dye leakage, and cell rounding. These changes reflected a temporal evolution of lysosomal damage, progressing from minor structural disruptions to more severe alterations as exposure continued, observable at the microscopic level. During the study, clinical observations of intoxicated rats included symptoms such as lethargy, reduced activity levels, and impaired motor coordination. High-dose Imidacloprid exposure led to noticeable behavioral changes, including decreased exploratory behavior and altered grooming patterns. Additionally, signs of neurotoxic effects, such as tremors or ataxia, were observed in the rats exposed to the higher dose, reflecting the systemic impact of chronic pesticide exposure. The results revealed a significant decrease in the enzymatic activities of CAT, GPx, and SOD, accompanied by an increase in GST activity. A notable reduction in glutathione levels and a rise in MDA index were observed, indicating enhanced oxidative stress in the brain. Mitochondrial impairment was evidenced by disturbances in oxygen consumption, increased swelling, and altered membrane permeability. Lysosomal destabilization was confirmed by reduced retention of neutral red dye, structural changes in lysosomes, and a significant rise in lysosomal pH in the IMI-exposed groups. In addition, the histopathological features indicate that imidacloprid at the given dose and exposure duration may have caused notable neurotoxic effects in Wistar rat brain tissue. Chronic exposure to Imidacloprid induces oxidative stress, mitochondrial dysfunction, lysosomal disruption and histopathological alterations in the central nervous system of Wistar rats. These findings provide valuable insights into the neurotoxic mechanisms of neonicotinoid pesticides, highlighting the need for further research to understand the long-term effects of Imidacloprid exposure on mammalian health.

Ergosterol Biosynthesis and Regulation Impact the Antifungal Resistance and Virulence of Candida spp.

Ergosterol is a key fungal sterol that is mainly found in the plasma membrane and is responsible for the proper membrane structure, rigidity, permeability and activity of membrane proteins. Ergosterol plays a crucial role in the ability of fungi to adapt to environmental stresses. The biosynthesis of ergosterol is also intimately connected with the antifungal resistance and virulence of pathogenic fungi. The most common etiological agents of life-threatening fungal infections are yeasts belonging to the genus Candida. The antifungal agents mostly used to treat Candida spp. infections are azoles, which act as competitive inhibitors of sterol demethylase, a key enzyme in the fungal ergosterol biosynthetic pathway. Although most studies on ergosterol biosynthesis, its regulation and the uptake of sterols are from the baker’s yeast Saccharomyces cerevisiae, the study of ergosterol biosynthesis and its relationship to antifungal drug resistance and virulence in pathogenic fungi is of utmost importance. The increasing antifungal drug resistance of Candida spp. and the limited armamentarium of antimycotics pose a challenge in the development of new therapeutic approaches. This review summarizes the available data on ergosterol biosynthesis and related phenomena in Candida albicans and non-albicans Candida species (Candida glabrata, Candida parapsilosis, Candida tropicalis and Candida auris) with special emphasis on C. albicans and C. glabrata as the most common etiological agents of systemic candidiasis.

Cell fixation improves performance of in situ crosslinking mass spectrometry while preserving cellular ultrastructure

Crosslinking mass spectrometry (XL-MS) has the potential to map the interactome of the cell with high resolution and depth of coverage. However, current in vivo XL-MS methods are hampered by crosslinkers that demonstrate low cell permeability and require long reaction times. Consequently, interactome sampling is not high and long incubation times can distort the cell, bringing into question the validity any protein interactions identified by the method. We address these issues with a fast formaldehyde-based fixation method applied prior to the introduction of secondary crosslinkers. Using human A549 cells and a range of reagents, we show that 4% formaldehyde fixation with membrane permeabilization preserves cellular ultrastructure and simultaneously improves reaction conditions for in situ XL-MS. Protein labeling yields can be increased even for nominally membrane-permeable reagents, and surprisingly, high-concentration formaldehyde does not compete with conventional amine-reactive crosslinking reagents. Prefixation with permeabilization uncouples cellular dynamics from crosslinker dynamics, enhancing control over crosslinking yield and permitting the use of any chemical crosslinker.

Lysosome Targeted Nanoparticle Aggregation Reverses Immunosuppressive Tumor Microenvironment for Cancer Immunotherapy.

Nanotechnology has proven its enormous application value in clinical practice. However, current research on nanomedicines mainly focuses on developing nanoparticles as delivery carriers to maximize the bioavailability of therapeutic agents, with little attention on exploring their potential to directly regulate physiological processes. In this study, inspired by the lysosomal swelling caused by excessive accumulation of undegraded substances, this work presents a lysosomal-targeting aggregated nanoparticle (LTANP) for cancer treatment. By rationally engineering surface composition, properties, and interparticle interactions, LTANP achieves efficient tumor accumulation and selective targeted aggregation in lysosomes of cancer cells, leading to unrelievable lysosomal swelling, and ultimately inducing lysosomal membrane permeabilization (LMP) of cancer cells. Further analysis shows that nanoparticle aggregation-mediated LMP can effectively trigger immunogenic cell death (ICD) by impairing autophagy-lysosome pathway, evoking robust antitumor immune responses and reversing tumor immunogenicity from "cold" to "hot" in a melanoma model. Additionally, LTANP can combine with clinically approved programmed death ligand-1 (PD-L1) antibodies to further unleash T cell-mediated antitumor immunity, significantly enhancing antitumor performance, inhibiting tumor recurrence and metastasis. This work demonstrates the potential of rationally engineered nanostructures in directly combating cancer and provides novel insights for the development of advanced nanoparticle-based cancer treatment.

The effects of metformin on inflammation and apoptosis in rats with preeclampsia.

Defined clinically by elevated blood pressure along with either proteinuria and/or maternal organ dysfunction, representing a major cause of morbidity and mortality pregnant women and newborns. Metformin (MET), an oral antidiabetic medication, has been shown to prevent preeclampsia (PE) through various mechanisms, including reducing inflammation, improving endothelial dysfunction, improving mitochondrial function, and altering cellular homeostasis and energy metabolism. Herein, we explored the role of MET in PE and its underlying molecular mechanisms using in in vivo experiments. RT-qPCR, Western blot (WB), and immunohistochemistry (IHC) were conducted to assess the mRNA or protein expression of genes related to mitochondrial apoptosis. Additionally, ELISA was conducted to quantify the expression of mitochondrial apoptosis and inflammation-related genes, as well as PE biomarkers. Treatment with MET in PE rats ameliorated hypertension and proteinuria, altered the expression of PE biomarkers, and significantly inhibited L-NAME-induced inflammation and cell apoptosis. MET modulated the levels of inflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and IL-10, mitigating inflammation in PE rats. Furthermore, MET regulated mitochondrial outer membrane permeability (MOMP), thereby reducing cell apoptosis occurring in the mitochondrial pathway of PE rats. This study demonstrates that MET alleviates inflammation and cell apoptosis in PE rats by modulating the expression of inflammatory factors and MOMP. Our results indicate that MET has huge therapeutic potential against PE.

Development of Tetracycline by AgO Nanoparticles and Studying its Activity on Antibiotic-Resistant Bacteria

General background: Antibiotic resistance in bacteria has become a critical global health issue, necessitating the development of new strategies to enhance antibiotic efficacy. Specific background: Nanoparticles, particularly silver nanoparticles (AgNPs), have emerged as potential enhancers of antibiotics due to their unique properties and interactions with bacterial cells. Knowledge gap: However, the combination of nanoparticles with existing antibiotics, such as tetracycline, and their impact on bacterial inhibition and safety has not been fully explored. Aims: This study aims to investigate the antibacterial activity of silver oxide nanoparticles (AgO NPs) combined with tetracycline (TCS) and evaluate their effectiveness against resistant bacterial strains. Results: AgO NPs were synthesized using a photodeposition method, yielding nanoparticles with an average diameter of 2.24 nm. The AgO NPs + TCS combination demonstrated superior antibacterial activity, with a minimum inhibitory concentration (MIC) of 16 μg/mL against Staphylococci and 32 μg/mL against Pseudomonas aeruginosa, significantly outperforming standard tetracycline. Hemolysis assays confirmed the safety of the synthesized compound at all concentrations. Novelty: Silver oxide nanoparticles and tetracycline exhibit a unique synergistic interaction, enhancing antimicrobial effects by increasing bacterial membrane permeability, facilitating greater antibiotic infiltration. Implications: These findings suggest that AgO NPs combined with tetracycline offer a promising solution to overcome bacterial resistance, providing a potent and safe alternative to conventional antibiotic treatments. Highlights: AgO NPs and tetracycline show enhanced antibacterial effects. More effective than standard tetracycline against resistant bacteria. Safe with no toxicity observed in hemolysis tests. Keywords: Antibiotic resistance, silver nanoparticles, tetracycline, photodeposition, antibacterial activity

Tea polyphenols coating improves physiological properties, microstructure and chemical composition of cuticle to suppress quality deterioration of passion fruit during cold storage

The plant cuticle plays a crucial role in modulating postharvest quality and extending shelf life of horticultural crops. Passion fruit often suffers from quality degradation primarily due to peel wrinkling after harvest. Tea polyphenols (TPs) hold potential for enhancing postharvest preservation. However, the specific effects of TPs coating on preservation of passion fruit, as well as the underlying mechanisms involving cuticle regulation, have not been thoroughly investigated. This study demonstrated that treating ‘Qinmi no.9’ passion fruit with TPs at a concentration of 0.1 g L−1 significantly mitigates weight loss, maintains firmness, and reduces cell membrane permeability during storage at 10 °C. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that TPs treatment notably enhances cuticle thickness and structural integrity. Furthermore, gas chromatography–mass spectrometry (GC–MS) and metabolomics analyses indicated that TPs treatment obviously promotes the accumulation of palmitic acid, stearic acid, and their derivatives—primarily 12-Octadecenoic acid and 10(E)-Octadecenoic acid—as well as increases the levels of 11-Octadecenoic acid, primary alcohols such as 1-Eicosanol, and long-chain alkanes (including C31 and C32 alkanes) in the fruit peel cuticle. These biochemical changes contribute to the quality maintenance of passion fruit during cold storage. The findings suggest that TPs treatment is a promising biological strategy for extending shelf life and mitigating quality degradation by regulating cuticle metabolism in postharvest passion fruit.

Pinonic Acid Derivatives Containing Thiourea Motif: Promising Antifungal Lead Compound Targeting Cellular Barrier of Colletotrichum fructicola.

In order to explore novel antifungal lead compounds from plant essential oil, thirty-two pinonic acid derivatives containing thiourea groups were designed and synthesized using α-pinene as a raw material. One of these pinonic acid derivatives compound 3a exhibited noteworthy in vitro antifungal activity against Colletotrichum fructicola (EC50 = 9.22 mg/L), which was comparable to that of the positive control kresoxim-methyl (EC50 = 9.69 mg/L). Structure-activity relationship (SAR) studies demonstrated that the introduction of thiourea groups, F atoms, and Cl atoms into the structure of pinonic acid derivatives significantly improved their antifungal activity. The in vivo antifungal test revealed that compound 3a could effectively control pear anthracnose. It also proved that compound 3a showed low acute oral toxicity to honeybees (LD50 > 100 μg/bee) and low or no cytotoxicity to LO2 and HEK293 cell lines. The preliminary mechanism of action studies revealed that compound 3a caused mycelium deformity, increased cell membrane permeability, blocked the normal process of phospholipase C on the cell membrane, and reduced mycelium protein content. The results of molecular docking studies demonstrated the stable binding of compound 3a to phospholipase C and chitin synthetase. This study suggested that compound 3a could be used as a promising lead compound for the development of novel antifungal agents targeting the cellular barrier of C. fructicola.

Lipid bilayer permeabilities and antibiotic effects of tetramethylguanidinium and choline fatty acid ionic liquids

Ionic liquids (ILs) have been studied as potential components in antibiotic formulations based on their abilities to permeabilize and penetrate lipid bilayer, which correlate with their antibacterial effects. Fatty acid-based ILs (FAILs), in which the anion is a long-chain fatty acid, can permeabilize lipid membranes and have been used in biomedical applications since they have low human cell cytotoxicity. In this work we investigated the abilities of several different FAILs to permeabilize lipid bilayers and how that permeabilization correlates with antibacterial activity, cell membrane permeability, and cytotoxicity. The FAILs consisted of the cations tetramethylguanidinium (TMG) or choline combined with octanoate or decanoate. These FAILs were tested on model bilayer vesicles with three different lipid compositions for membrane permeabilization using a leakage assay. They were then tested for antibiotic and membrane permeabilization on bacterial and mammalian cells. The results show that while the octanoate-based FAILs do not form micelles and have low activities on vesicles and biological cells, the decanoate-based FAILs can permeabilize bilayers and have biological activities that correlate with the model vesicle results. The ILs with both cation and fatty-acid anion have strong activities while the decanoate alone has only minimal permeabilization and antibiotic activity. Membrane permeabilization occurs at FAIL concentrations below their CMC values which suggests that their mechanism of action may not involve micelle formation.

Effects of lanthanides on the structure and oxygen permeability of Ti-doped dual-phase membranes

The trade-off effect of the oxygen permeability and stability of oxygen transport membranes (OTMs) still exists in working atmospheres containing CO2. Herein, we reported a new series of 60 wt%Ce0.9Ln0.1O2-δ-40 wt%Ln0.6Sr0.4Fe0.9Ti0.1O3-δ (CLnO-LnSFTO, Ln = La, Pr, Nd, Sm, Gd, Tb) dual-phase OTMs by selecting different Ln elements based on the reported highly stable Ti-doped CPrO-PrSFTO. The effects of different Ln elements on the structure and oxygen permeability of Ti-doped dual-phase OTMs were systematically studied. Basically, as the atomic number of Ln elements increases, the unit cell parameters of both the fluorite phase and the perovskite phase become smaller. The unit cell volume and spatial symmetry of the perovskite phase are reduced, resulting in a reduction in oxygen permeability. The optimal CLaO-LaSFTO showed JO2 of 0.60 and 0.54 mL min−1 cm−2 with He and CO2 sweeping at 1000 °C, respectively. In addition, all CLnO-LnSFTO OTMs could work for more than 100 h with no significant performance degradation in a CO2 atmosphere, maintaining excellent stability. This work explores candidate OTM materials for CO2 capture and oxygen separation, as well as provides some ideas for addressing the trade-off effect.

Simple fabrication of breathable poly (vinylidene fluoride) fibrous membranes decorated by silica nanoparticles with enhanced waterproof property

In recent years, scientists have undertaken various preparation approaches to improve the waterproof and moisture permeability of fiber membranes, among which electrospinning has emerged as the simplest and most effective one. In this paper, poly (vinylidene fluoride) /silica (PVDF/SiO2) fibrous membranes were prepared by one-step electrospinning combined with heat treatment. The morphology, surface wettability, water resistance and moisture permeability of the fibrous membranes were also characterized. When the concentration of PVDF was 12 wt.%, the nanofiber membranes exhibited the most uniform and optimal morphology. In addition, the fiber membranes not only exhibited a high water contact angle (WCA) (135.56 °) and a small maximum pore size (dmax) (1.77 μm), but also demonstrated a large hydrostatic pressure (116.86 kPa) and a moderate water vapor transmission rate (WVTR) (3.53 kg m-2 d-1). The PVDF/SiO2 fibrous membranes with good waterproof and moisture permeability obtained in this work are expected to improve the comfort of protective textiles and expand the application range.

Separating Neroli from Water Using the PDMS‐ZSM5 Mixed Matrix Membrane and the Pervaporation Method

AbstractIn this study, the separation of neroli from water by PDMS‐ZSM5 mixed matrix membrane and separation performance of the pervaporative process of the prepared membranes with the parameters of permeability flux and separation factor was investigated. The effect of adding nanoparticles in the polymer matrix, the effect of the operating parameter of temperature and concentration on the efficiency of the membrane in the pervaporative process to be placed. Comparison of the results for pure membrane and mixed matrix membrane shows a 3‐fold increase in flux along with a 5‐fold increase in the separation factor in the mixed matrix membrane with a ratio of 12% nano in the membrane matrix so that the permeability and separation factor are 1.256 kg/m2h and 550, respectively. Membrane function was also evaluated in the temperature range of 298–353 K and feed concentration of 122–209 ppm. With increasing temperature to 353 K, permeability of membrane containing 8% ZSM‐5 nanoparticles increased from 0.63 to 0.89 kg/m2h. Also, with increasing feed concentration, permeability increased from to 0.96 kg/m2h. The optimization of these conditions was investigated by response surface method (RSM) based on the design of central points (CCD). The effect of all three parameters on the permeability, flux, and separation factor was investigated simultaneously and the optimal conditions were obtained at 12 wt% of ZSM‐5, a concentration of 209 mg/L of neroli, and a temperature of 304 K. Under these optimal conditions, the values of permeability, flux, and separation factor were 1.414 kg/m2h and 1039.57, respectively.

Surface functionalized porous MXene (Ti3C2Tx)/Polyethyleneimine membrane for efficient osmotic energy conversion

The development of ion-selective membranes is crucial for achieving efficient osmotic power conversion in reverse electrodialysis system. However, balancing ion selectivity and ion permeability in membranes remains a challenge, limiting improvements in energy conversion efficiency for practical applications. In this study, we develop efficient cation exchange membranes by integrating versatile aromatic hydroxyl groups with MXene nanosheets and polyethyleneimine (PEI) into their lamellar structure. This approach holds promise for achieving non-swelling, high selectivity, and enhanced power density for osmotic energy conversion. The abundance positive surface charge within PEI molecules, combined with the 2D sub-nanochannels of MXene nanosheets, facilitates the biomimetic replication of channel size, chemical groups, and adjustable charge density in the resulting membranes. The fabrication of these membranes is easily achieved through simple hydrothermal, functionalization, and surface-charged techniques, suggesting promising scalability. These membranes exhibit remarkable stability against swelling in aqueous solutions for up to 25 days and demonstrate a high selectivity of 0.95 and a superior output power density of 18.3 W/m2 in artificial river water and seawater.

Probing the interaction mechanisms between three β-lactam antibiotics and penicillin-binding proteins of Escherichia coli by molecular dynamics simulations

The presence of antibiotic residues in the aquatic environments poses great potential risks to the aquatic organisms, and even human health. Elucidating the interaction mechanisms between antibiotics and biomacromolecules is crucial for accurately assessing and preventing their potential risks. Therefore, the toxicity of three beta-lactam antibiotics on Escherichia coli (E. coli) was investigated by using the time-dependent toxicity microplate analysis method in this study. Then, molecular docking and molecular dynamics simulation technologies were used to elucidate the potential molecular interactions between β-lactam antibiotics and penicillin-binding proteins of E. coli, and their correlation with the physical and chemical behaviors observed in the physiological and biochemical experiments. The results show that three antibiotics exert inhibitory effects on E. coli cells by modifying their membrane permeability, and even more severe cell damage including rupture, wrinkling, adhesion, indentation, elongation and size alterations. But, toxic effect of the three antibiotics on E. coli varies, and toxicity order is followed by meropenem > cefoperazone > amoxicillin. Van der Waals forces play a vital role in the molecular interactions between the three antibiotics penicillin binding protein of E. coli and the sequence of binding free energy is consistent with the observed toxicity order. Shape compensation is the principal determinant for the binding of antibiotics to penicillin binding proteins, which pertains to the drug-induced alteration in the three-dimensional conformation of penicillin binding proteins.

Role of ferroptosis in mitochondrial damage in diabetic retinopathy

Diabetic retinopathy is driven by oxidative stress-mitochondrial damage. Activation of ROS producing cytosolic NADPH oxidase 2 (Nox2) in diabetes precedes retinal mitochondrial damage, initiating a vicious cycle of free radicals. Elevated ROS levels peroxidize membrane lipids increasing damaging lipid peroxides (LPOs). While glutathione peroxidase 4 (GPx4) neutralizes LPOs, an imbalance in its generation-neutralization leads to ferroptosis, which is characterized by increased LPOs, free iron and decreased GPx4 activity. Mitochondria are rich in polyunsaturated fatty acids and iron and have mitochondrial isoform of GPx4. Our aim was to investigate mitochondrial ferroptosis in diabetic retinopathy, focusing on Nox2 mediated ROS production. Using human retinal endothelial cells, incubated in 5mM or 20mM D-glucose for 12 to 96 hours, with or without Nox2 inhibitors (100μM apocynin, 5μM EHop-016 or 5μM Gp91 ds-tat), or ferroptosis inhibitors (1μM ferrostatin-1, 50μM deferoxamine) or activator (0.1μM RSL3), cytosolic and mitochondrial ROS, LPOs, iron, GPx4 activity, mitochondrial integrity (membrane permeability, oxygen consumption rate, mtDNA copy numbers) and cell death were quantified. High glucose significantly increased ROS, LPOs and iron levels and inhibited GPx4 activity in cytosol, and while Nox2 and ferroptosis inhibitors prevented glucose-induced increase in ferroptosis markers, mitochondrial damage and cell death, RSL3, further worsened them. Furthermore, high glucose also increased ferroptosis markers in the mitochondria, which followed their increase in the cytosol, suggesting a role of cytosolic ROS in mitochondrial ferroptosis. Thus, targeting Nox2-ferroptosis should help break down the self-perpetuating vicious cycle of free radicals, initiated by the damaged mitochondria, and could provide novel therapeutics to prevent/retard the development of diabetic retinopathy.

Membrane Permeability and Drug Targeting Potential of Phospholipid‐Based Nanocarriers in Lung Cancer Therapy

AbstractLung cancer has become the leading cause of cancer‐related deaths, surpassing all other forms of cancer. Among lung cancers, non‐small cell lung cancer (NSCLC) accounts for approximately 85% of cases. The use of tobacco, genetic traits, and radiation exposure are amongst the major reasons of lung cancer. The ongoing research in the medical field has considered the efficacy of nanocarriers in targeting various cancer cells. Among several biomaterials, lipid‐based nanocarriers have gained special attention due to their excellent compatibility, improved targeting efficacy, and encapsulation ability of diverse therapeutic agents. Phospholipids are naturally occurring amphiphilic moieties found in all living creatures. The presence of phospholipids in biomembrane aids the permeability of phospholipid‐based drug carrier. It can also facilitate targeting of therapeutic agents to cancer microenvironment without degrading the encapsulated drug. Phospholipids can be employed to develop conjugated nanocarriers and vesicular nanoformulation that can result in prolonged circulatory half‐life and controlled release of drugs. Phospholipids are also suitable biomaterials to attach a ligand for tissue‐specific targeting. Recent researches have reported effective targeting of chemotherapeutic agents, genes, and vaccines through phospholipid‐based nanocarriers to lung cancer cells. This review focuses on the rationality and applications of phospholipid‐based nanocarriers in lung cancer therapy.