Search Results (3,954)

This study investigates the development of mixed matrix membranes based on polyethersulfone incorporated with attapulgite for gas separation applications, addressing the existing gap regarding the use of this mineral in dense membranes obtained exclusively by solvent evaporation and its combined effects on microstructure and transport. The membranes were prepared by phase inversion via solvent evaporation, using solvent/polymer ratios of 75/25 and 80/20 and a thickness of 0.25 mm. The solutions were evaluated in terms of viscosity, and the membranes were characterized by structural techniques such as X-ray diffraction (XRD), atomic force microscope (AFM), contact angle, mechanical properties (tensile testing), and water vapor permeation. The results showed that attapulgite incorporation promoted a reduction in surface roughness (up to ~40%) and a decrease in contact angle (from ~89° to ~68°), indicating increased hydrophilicity. In addition, water vapor permeability was influenced in a non-linear manner, with optimized performance observed at 3 wt% filler loading. Solution viscosities remained within ranges suitable for processing. Structural analyses indicated compatibility between the phases, while morphology changes dependent on filler content were decisive for transport behavior. It is concluded that attapulgite is a promising additive for fine-tuning membrane properties, enabling optimization of the sorption–diffusion balance and improvement of membrane performance in separation applications. Full article

Background: Carbonic Anhydrases (CAs) represent regulators of cell adaptation to hypoxia, pH regulation, and metabolic fitness. Among cancers, multiple myeloma (MM) is a plasma cell malignancy sustained by hypoxia-driven metabolic adaptation, extracellular acidification, and redox imbalance. Tight regulation of tumor extracellular pH, mediated by Carbonic Anhydrases IX and XII, is crucial for myeloma survival, progression, and stemness, making these isoforms attractive therapeutic targets. Methods: We designed and synthesized a library of terpenoid-based hybrids by derivatizing chlorothymol and 4-isopropyl-3-methylphenol with either the natural coumarin umbelliferon or the 2,2′-dipicolylamine (DPA) scaffold. This chemical strategy aimed to selectively inhibit tumor-associated CAs IX/XII through coumarin- or DPA-mediated recognition, while terpenoid fragments were introduced to enhance lipophilicity, membrane permeability, and potential redox-modulating properties. The compounds were tested by a Stopped-Flow assay for CA inhibition, in cell-based assays for antiproliferative properties and by means of several antioxidant assays. Results: The most active compounds, connecting the coumarin core to a terpenoid tail, inhibited the targeted CAs in the nanomolar range, showing up higher selectivity over off-target isoforms (I and II). In studies performed on MM cell lines, selected derivatives reduced viability (IC₅₀ = 15.8–85.4 µM) and displayed favorable selectivity over normal cells. In silico investigations suggested that the compounds were able to interact selectively with the target enzymes. Conclusions: Collectively, these results support a dual-targeting strategy in which selective inhibition of tumor-associated CAs, combined with redox modulation, interferes with adaptive mechanisms of MM cells, providing a rational framework for the development of multifunctional agents against metabolically resilient hematological malignancies. Full article

Cell encapsulation within semipermeable membranes is a promising strategy for protecting transplanted cells from host immune responses, while permitting the diffusion of nutrients and therapeutic molecules. Although alginate-based microcapsules are commonly used, ionically crosslinked capsules often exhibit limited structural stability and tunability in terms of membrane permeability. In this study, we developed covalently stabilized microcapsules. Alginate microgel beads were first prepared as sacrificial templates and subsequently coated with phenol-modified chitosan and hyaluronic acid (Chitosan–Ph and HA-Ph) via layer-by-layer assembly. The multilayer membrane was then covalently stabilized through horseradish peroxidase (HRP)-mediated oxidative coupling of phenol groups, followed by liquefaction of the alginate core. The crosslinked microcapsules maintained structural integrity after liquefaction, while markedly reducing γ-globulin permeation under in vitro conditions and preserving β-cell viability and glucose responsiveness. The findings of this study demonstrate the feasibility of this system as an in vitro platform for stable cell encapsulation, with potential relevance to cell therapy. Full article

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a major cause of morbidity and mortality worldwide, particularly due to the emergence of drug-resistant strains. Membrane-active antimicrobial peptides (AMPs) represent attractive therapeutic candidates because they target bacterial envelope integrity and disrupt essential cellular processes. We evaluated two rationally designed LL-37-derived peptides: a truncated C-terminally amidated analog (LL37-1) and a modified variant incorporating N-terminal acetylation and a single D-amino acid substitution (D-LL37). Dose–response analysis demonstrated that D-LL37 exhibited greater antimycobacterial potency, with lower inhibitory concentrations of 90% (IC₉₀) and 50% (IC₅₀) values (18.40 ± 0.39 μM and 10.11 ± 0.60 μM, respectively) compared with LL37-1 (25.44 ± 0.36 μM and 15.45 ± 1.40 μM). Fluorescence-based permeability assays revealed partial membrane disruption (36% and 44% at IC₉₀ for LL37-1 and D-LL37, respectively), which was supported by ultrastructural alterations observed by scanning electron microscopy, including bacillary shortening, rough surface formation, cell clusters, and the presence of cellular debris, all of which are consistent with membrane damage. RT-qPCR analysis demonstrated significant upregulation of the P-type ATPase genes ctpF, ctpA, and ctpH following D-LL37 exposure. Collectively, these findings indicate that optimized LL-37-derived peptides exert antitubercular activity associated with envelope perturbation and coordinated activation of ion transport-related stress responses. Full article

The rapid proliferation of microalgae in aquatic systems poses significant environmental and public health challenges, particularly in regions lacking adequate water treatment facilities. This study reports a sustainable approach for microalgae removal through the development of low-cost membranes derived from expanded polystyrene (EPS) waste and modified with polyethylene glycol (PEG) as a pore-forming agent. Membranes were fabricated via non-solvent-induced phase separation with PEG loadings of 0–20 wt.% and characterized in terms of morphology, porosity, wettability, and hydraulic performance. Filtration efficiency was evaluated using Spirulina platensis as a model microalga. Incorporation of PEG (up to 15 wt.%) enhanced membrane porosity (77–84%), improved hydrophilicity (water contact angle reduced from 68° to 48°), and increased water flux (10.98–39.2 L·m⁻²·h⁻¹), while maintaining complete microalgal rejection (100%). Optimized membranes exhibited asymmetric finger-like structures, contributing to improved permeability. Full article

Perovskite mixed proton–electron hydrogen-permeable membranes have been widely applied in the field of membrane separation due to their 100% selectivity for hydrogen separation. La_5.5WO_11.25-δ-La_0.87Sr_0.13CrO_3-δ (LWO-LSF) four-channel hollow fiber membranes were prepared by the phase inversion and sintering technique using a one-step thermal processing (OSTP) approach. The effects of temperature, feed gas concentration, sweep gas flow, permeation mode, and water vapor on hydrogen flux were systematically investigated. At 900 °C, the hydrogen permeation flux of 50% H₂/N₂ feed from the shell side to the lumen side was 0.613 mL·min⁻¹·cm⁻², which was 62.59% higher than that from the lumen side to the shell side. The enhanced hydrogen permeation performance is attributed to the lower gas mass transfer resistance under shell-side feeding. Under humidified conditions on the sweep side, the hydrogen flux increased by an additional 3.42%. The presence of water vapor increased the number of proton carriers, effectively enhancing proton–electron-coupled transport and thereby increasing the hydrogen permeation flux. Full article

Developing membranes with superior antifouling properties is crucial for efficient and sustainable water treatment. In this study, polysulfone (PSM) composite membranes were fabricated by incorporating hydroxylated titanium nanotubes (TNT@OH) via the non-solvent-induced phase separation method. The hydroxylation of TNTs enhanced their dispersion in the polymer matrix and promoted strong polymer–nanoparticle interactions. Comprehensive characterization using FTIR, XRD, TGA, FESEM, and AFM confirmed the successful integration of TNT@OH, resulting in membranes with improved hydrophilicity, porosity, and thermal stability. The contact angle decreased from ~88° for neat PSM to ~50° at 7 wt% TNT@OH, while surface free energy increased significantly. Mechanical strength and flexibility were also enhanced at optimal TNT@OH loadings (3–5 wt%), owing to uniform dispersion and strong interfacial bonding. Filtration experiments using humic acid (HA) and natural organic matter (NOM) demonstrated remarkable improvements in water flux, rejection efficiency, and fouling resistance. The composite membranes achieved HA rejection rates of up to 98%, with reduced irreversible fouling and higher flux recovery ratios across multiple filtration–cleaning cycles. The proposed antifouling mechanism is attributed to the formation of a stable hydration layer by surface hydroxyl groups, which prevents foulant adhesion and facilitates cleaning. These findings suggest that incorporating TNT@OH into polysulfone membranes is a promising approach for developing high-performance ultrafiltration membranes with enhanced permeability, mechanical robustness, and long-term antifouling stability, thereby making them suitable for advanced water purification applications. Full article

Background: Terahertz (THz) waves exhibit both photon-like and electron-like properties, showing emerging potential in biomedical applications. Cutaneous squamous cell carcinoma (CSCC) is one of the most common skin tumors. Studies have reported that THz waves can induce apoptosis in cancer cells or ablate tumor tissues. Our previous studies also confirmed that 0.1 THz radiation could significantly promote apoptosis in cutaneous melanoma cells, while it had no apparent effect on fibroblast viability, proliferation, migration, and apoptosis. However, the effects of 0.1 THz radiation on CSCC cells have not yet been explored. Furthermore, there remains a lack of investigation into the structural and functional effects on fibroblasts. Therefore, it is necessary to conduct a systematic study to evaluate the influence of 0.1 THz radiation on both CSCC cells and fibroblasts in order to better understand its potential therapeutic applications in the treatment of skin cancer. Purpose: This study aims to explore the biological effects of 0.1 THz radiation on SCC-7 cells and to uncover the molecular mechanisms underlying THz-induced apoptosis, as well as its potential effect on L-929 cells. Methods: Cell viability was evaluated through the CCK-8 assay, while cell cycle distribution was analyzed with the DNA content detection kit. Wound healing assays were performed to assess cell migration, and Annexin V-FITC staining was used to detect apoptosis. Caspase-3 activity was measured using the caspase-3 activity assay kit. Cell morphology was observed using the Atomic Force Microscope (AFM) and the Transmission Electron Microscopy (TEM). Alterations in membrane potential were detected with the M09 membrane potential probe kit, and intracellular Ca²⁺ levels were quantified using the Fluo-8 AM fluorescent probe. Mitochondrial permeability transition pore (mPTP) opening was assessed with the MPTP detection kit, mitochondrial membrane potential changes were measured using the JC-1 probe kit, and cellular ATP levels were measured with the enhanced ATP assay kit. Subsequently, proteomic analysis was performed. Intracellular reactive oxygen species (ROS) levels were quantified with the ROS detection kit, and cytochrome c (Cyt c) release was quantified using the mouse Cyt c ELISA kit. Apoptosis-inducing factor (AIF) expression was analyzed at both mRNA and protein levels by quantitative real-time PCR (qPCR) and Western blot. AIF expression in CSCC tissues was further evaluated based on the GSE42677 and GSE45164 databases. Finally, cyclosporin A (CsA) was used to inhibit mPTP, and in combination with the iMAC inhibitor, the Aifm1 expression and Cyt c release were examined. Results: Our results showed that THz waves significantly disrupted the membrane integrity of SCC-7 cells and induced mitochondrial structural and functional damage. This resulted in a significant increase in ROS levels and the activation of mPTP and the mitochondrial apoptosis channel (MAC). THz radiation promoted the release of Cyt c and AIF from mitochondria, triggering a noncanonical caspase-3-dependent apoptosis pathway. Notably, L-929 cells did not show significant phenotypic or apoptotic changes under the same irradiation conditions. Bioinformatics analysis of the Gene Expression Omnibus (GEO) database revealed that AIF expression was significantly altered in CSCC tissues compared to normal skin tissues. Conclusions: These findings indicated that 0.1 THz radiation effectively induced apoptosis in SCC-7 cells by triggering mitochondrial dysfunction and ROS generation, which led to the release of AIF. Furthermore, the dysregulation of AIF in CSCC tissues suggested its potential as a promising biomarker. These results provided important molecular insights into the therapeutic potential of THz radiation, particularly for the treatment of cutaneous squamous cell carcinoma. Full article

Background/Objectives: The escalating crisis of antibiotic resistance and the inherent limitations of conventional antibiotics necessitate the development of innovative therapeutic strategies. Targeted drug delivery (TDD) offers a powerful approach to enhance efficacy, minimize systemic toxicity, and circumvent bacterial resistance. This systematic review aims to evaluate the potential of unique bacterial transport systems (BTSs), surface specific receptors and intracellular enzymes as platforms for TDD via the “Trojan Horse” strategy (THS). Methods: A comprehensive literature review was conducted, focusing on studies that investigated the specificity and mechanisms of BTSs responsible for the uptake of metabolites that are essential for and unique to bacteria. This includes an analysis of transport systems for siderophores, bacteria-specific sugars, cell wall components, D-amino acids, and vitamins. We assessed preclinical and clinical examples of drug conjugates utilizing these pathways, as well as emerging platforms such as bacteriophage-derived proteins, antibody–antibiotic conjugates, and bacterial extracellular vesicles (EVs). Results: BTSs demonstrate high specificity for their cognate substrates, providing effective molecular gateways for TDD of drugs photosensitizers and diagnostic probes in form of conjugates. The siderophore–cephalosporin conjugate cefiderocol represents a clinically validated example, having received FDA approval. Preclinical studies further reveal that conjugates utilizing sugars (e.g., maltose, trehalose) and vitamins (e.g., B12) can significantly enhance antibiotic uptake and activity against both Gram-positive and Gram-negative pathogens, including drug-resistant strains. Emerging platforms like bacteriophage endolysins and engineered EVs show promise for overcoming biological barriers such as bacterial outer membranes and intracellular host niches. Conclusions: The THS leveraging BTSs represents a clinically viable and promising avenue for next-generation antibacterial therapies. Advantages of BTS include overcoming bacterial resistance, such as reduced membrane permeability and efflux pumps, enabling the “revival” of antibiotics that are poorly permeable or toxic, increasing their local concentration at the target site and reducing side effects on host cells. While significant progress has been made, a striking disconnect persists between the hundreds of conjugates demonstrating potent in vitro activity and the limited agent that has achieved clinical use. This in vitro–in vivo gap reflects, in large part, the early stage of this field rather than a fundamental failure. Further research is critically needed not only to identify novel BTSs and optimize drug-linker chemistry, but also to systematically address the translational barriers—including poor pharmacokinetics, immunogenicity, and unexpected toxicity—that have prevented most promising candidates from advancing beyond preclinical evaluation. Full article

Peptide therapeutics occupy a unique chemical space between small molecules and biologics, combining high target specificity with structural programmability and favorable safety profiles. Recent regulatory approvals and expanding clinical pipelines underscore the growing therapeutic and commercial relevance of peptide-based drugs. This review outlines chemical modification approaches and contemporary design strategies, and evaluates their impact on proteolytic stability, pharmacokinetics, membrane permeability, and target engagement. We then highlight recent advances in artificial intelligence (AI)-guided peptide drug design, including machine learning models, protein language models, and generative architectures that enable high-throughput activity prediction, property optimization, and de novo sequence generation. These approaches collectively accelerate the traditional discovery–design–validation cycle while reducing experimental attrition through data-driven, structure-informed modeling frameworks. Among these applications, AI also enables the rational design of cell-penetrating peptides (CPPs) to enhance intracellular delivery and biological activity. Building on these methodological advances, we further examine their application to peptide therapeutics, with particular emphasis on AI-based predictive models for CPPs as well as on therapeutic applications within the central nervous and pulmonary systems. We conclude by outlining future perspectives and emphasize that the systematic integration of AI-enabled sequence design with rational chemical engineering and advanced delivery technologies, supported by rigorous experimental validation, will be critical for developing robust and clinically durable peptide-based medicines. Full article

Background/Objectives: Staphylococcus aureus persister cells significantly undermine antimicrobial therapy through their transient antibiotic tolerance, contributing to chronic and recurrent infections. Although monoglycerides have shown potential as membrane-active antimicrobial agents, their effect on persister cells remains insufficiently understood. Methods: In this study, we evaluated the anti-persister activities of monocaprin, monolaurin, and monomyristin against S. aureus persister cells. Mechanistic analyses were performed using membrane permeability assays and fluorescence microscopy. Results: All three monoglycerides reduced persister cell survival, with varying degrees depending on fatty acid chain length. Monolaurin exhibited the greatest anti-persister activity, whereas monocaprin and monomyristin exerted concentration-dependent bactericidal effects. Mechanistic analyses revealed that these compounds increased membrane permeability, thereby compromising cell viability in S. aureus persister cells. In contrast, Tween 80 attenuated both the bactericidal effect and the increase in membrane permeability, supporting the involvement of membrane disruption in their mode of action. Conclusions: The antibacterial activity of monocaprin, monolaurin, and monomyristin against S. aureus is closely associated with membrane damage. These membrane-active monoglycerides represent promising antimicrobial candidates for the eradication of S. aureus persister cells. Full article

The microporous layer (MPL) is a key functional component in proton exchange membrane fuel cells (PEMFCs), and clarifying the quantitative relationship between its microstructure and mass transport properties is essential for improving cell performance. In this study, a three-dimensional MPL model was developed using a stochastic reconstruction method, and, together with a random walk algorithm, was employed to systematically investigate the effects of porosity, carbon sphere radius, maximum overlap ratio, seed ratio, and polytetrafluoroethylene (PTFE) content on permeability, effective diffusivity, and tortuosity. The results reveal that increasing porosity reduces tortuosity from 1.7 to 1.3, while permeability and effective diffusivity increase by factors of approximately 6.5 and 1.8, respectively. As the carbon sphere radius increases, tortuosity decreases from 1.55 to 1.35, accompanied by an increase in permeability from 2 × 10⁻¹⁶ m² to 20 × 10⁻¹⁶ m². Moreover, increasing the PTFE content raises permeability from 5 × 10⁻¹⁶ m² to 22.5 × 10⁻¹⁶ m², corresponding to an enhancement by a factor of approximately 4.5. The high-accuracy fitting equations obtained from the simulation results provide theoretical guidance for the microstructural design and optimization of MPLs, which can enhance oxygen transport and water management, reduce mass transport losses, and thereby benefit high-power-density operation and the overall efficiency of PEM fuel cells. Full article

N-nitrosamine compounds, a disinfection byproduct of chlorination and chloramination in water and wastewater treatment processes, are classified as a probable human carcinogen. The current review focuses on analysing the feasibility of membrane technology while examining the challenges and opportunities in the elimination of N-nitrosamine compounds, particularly NDMA, from wastewater. To systematically attain this goal, this paper uses a systematic literature review that screens and critically assesses peer-reviewed experimental and numerical published papers on N-nitrosamine removal, occasioning in 37 high-quality papers for synthesis. In this regard, a detailed analysis of experimental and numerical studies elaborates that conventional RO membranes often introduce a specific low removal of NDMA from wastewater due to their low molecular weight and neutral charge, which addresses a critical issue. The critical analysis of the experimental and numerical studies depicts that the membrane type, structural properties, and chemical interaction have a key role in the removal of NDMA. To systematically improve the NDMA removal, a wide set of investigations have explored innovative treatment methods, including Nano pore plugging and hydrophilic coatings. This demonstrates potential for improving NDMA removal, albeit at the penalty of reduced water permeability. Additionally, the heat treatment of membranes has attained a notable improvement, ensuing in NDMA rejection of up to 92%. A multi-stage RO configuration model has depicted a maximum NDMA rejection of 93.1%. The future research should focus on investigating possible improvement of NDMA removal from wastewater such as Nano pore plugging and hydrophilic coatings, besides optimising RO configurations and membrane designs with a deeper understanding of membrane fouling. Full article

Breast cancer remains a major global health challenge, necessitating the development of effective anticancer strategies to overcome drug resistance and reduce the adverse effects of chemotherapy. Selenium-based therapies have demonstrated promising anticancer activity in various experimental models, including drug-resistant breast cancer cells. Selenium is an essential micronutrient required for the proper functioning of numerous biological processes in human cells. Selenoproteins play key roles in antioxidant defense, redox regulation, and immune system function. Selenium-containing compounds are characterized by high specificity, relatively low toxicity, and favorable cell membrane permeability, which supports their potential application in precision medicine. These compounds can inhibit cancer cell growth through multiple mechanisms, including modulation of redox balance, induction of apoptosis, and interference with signaling pathways involved in tumor progression. This review summarizes current knowledge on the mechanisms by which selenium compounds affect drug-resistant breast cancer cells, highlights key experimental findings, and discusses their potential use as adjuncts to conventional therapies. Full article

Oenococcus oeni (O. oeni) can initiate and complete the malolactic fermentation (MLF) process, which significantly improves wine quality. However, stress factors commonly encountered in wine, such as acid stress and ethanol stress, can hinder this process. Overexpression of certain key functional genes using genetic recombination technology can enhance the stress tolerance of O. oeni. In this study, the large-conductance mechanosensitive channel (mscl) gene was overexpressed in O. oeni SD-2a using genetic recombination technology. The results showed that overexpression of this gene enhanced the growth rate of O. oeni under 10% ethanol stress conditions. Physiological index measurements indicated that overexpression of this gene enhanced the control of cell membrane permeability in the recombinant strain at different time points under ethanol stress and altered cell membrane fluidity at these time points. Proteomic analysis after 12 h of treatment under 10% ethanol stress revealed that mscl overexpression significantly altered the protein expression pattern of O. oeni. The most significantly affected proteins included some cell membrane transporters (for sugars, lipids, amino acids, and nucleotides) and proteins involved in cell wall synthesis. These results suggest that mscl overexpression enhances the ethanol stress tolerance of O. oeni by altering its cell membrane properties and affecting the expression levels of proteins related to cell membrane transport and cell wall synthesis. This study provides a theoretical reference for obtaining O. oeni recombinant strains with enhanced stress tolerance through genetic recombination technology. Full article