Search Results (571)

Ocular infections and inflammation represent a clear risk to eye health, but standard eye masks often lack the necessary therapeutic features. Moreover, most existing studies employ a blended electrospinning approach, which leads to an inhomogeneous spatial distribution of the therapeutic agents. However, using the coaxial technique can address these limitations. This study develops a coaxial electrospun nanofibrous eye mask with dual antibacterial and antioxidant functions, aiming to provide an innovative ocular treatment tool for eye care. Generally, a core-shell structured bilayer polycaprolactone-polylysine/polyvinyl alcohol-resveratrol (PCL-PLs/PVA-RSV) membrane is successfully prepared by coaxial electrospinning, where the core is resveratrol-loaded PVA and the shell is PLs-loaded PCL. Results show uniform fiber morphology, favorable hydrophilicity, and potential for sustained release due to core-shell design. The membrane significantly inhibits the growth of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli); at the same time, it exhibits excellent free radical scavenging ability and good component biocompatibility, achieving slow release of the two drugs and long-term antioxidant effect. This multifunctional platform offers a synergistic approach to combating microbial infection and oxidative stress, showing great potential for eye care. Full article

Sulfonated aromatic polymers (SAPs) represent promising alternatives to perfluorinated ionomers for proton-exchange membrane fuel cells (PEMFCs), but their high hydrophilicity and limited chemical stability often require structural reinforcement and controlled cross-linking. In this study, composite membranes based on sulfonated poly(phenylsulfone) (SPPSU) and sulfonated poly(ethersulfone) (SPES) were fabricated with and without electrospun PPSU nanofiber mats and subsequently cross-linked through a solvent-induced sulfone-bridge formation at 180 °C. SPPSU/SPES blends (70/30, 50/50, 30/70) displayed good miscibility, while PPSU fibers improved dimensional stability and suppressed excessive swelling. Cross-linking strongly influenced membrane properties: intermediate treatment (20 h) enhanced mechanical strength and solvent resistance with limited loss of IEC, whereas extended treatment (30 h) produced highly stable, low-swelling networks. Despite lower IEC and water uptake, 30 h-treated membranes exhibited higher proton conductivity, attributed to reduced tortuosity and more continuous ionic pathways. Mechanical and hydration analyses identified SPPSU-50, SPPSU-70, and SPPSU-100 as the most balanced compositions. Proton mobility analysis revealed high membrane tortuosity, consistent with dense cross-linked structures reinforced by fibers. Overall, the combined use of SPPSU/SPES blending, PPSU nanofiber reinforcement, and sulfone-bridge cross-linking yields robust, water-insoluble membranes with improved electrochemical performance suitable for PEMFCs and other applications. Full article

Poly(vinylidene fluoride) (PVDF)-based ultrafiltration membranes play key roles in aqueous separation fields. However, the inherent hydrophobicity of PVDF always generates higher water permeation resistance and a greater fouling tendency in the filtration process. Different to the widely reported and widely used blending methods of increasing the hydrophilicity of PVDF membranes, the mass-produced hydrophilic PVDF copolymer is expected to be more efficient in producing high performance membranes. For this purpose, the present research offers a new and scalable approach to improving the hydrophilic properties of PVDF-based membranes through amphiphilic copolymers. Using 2-trifluoromethylacrylic acid (MAF) and hexafluoropropylene (HFP), carboxylated PVDF (PVHM) was synthesized following simple radical suspension copolymerization. Via a non-solvent-induced phase separation (NIPS) method, PVHM membranes were prepared and characterized. It was found that the PVHM membranes had enhanced hydrophilicity, permeability, fouling resistance, and alkali resistance compared with PVDF membranes. For the PVHM containing 8.3 wt% MAF, its membrane demonstrated superior static/dynamic fouling resistance to sodium alginate (FRR up to 99.1% for SA). Therefore, carboxylated PVDF polymers show potential for use in the industrial production of high-performance ultrafiltration membranes. Full article

Growing interest in natural therapies has increased the demand for essential oils; however, the complex interactions within their mixtures that dictate their final efficacy remain poorly understood. This study aimed to optimize a blend of ginger, cinnamon, tea tree, and geranium essential oils to develop an active ingredient, with synergistic multifunctional bioactivities, that was relevant to cutaneous healing. Initially, the composition and cytotoxicity for individual oils were determined; subsequently, a D-optimal mixture design was employed to evaluate three biological responses related to skin recovery: ultraviolet B radiation absorption, red blood cell lysis inhibition, and catalase enzyme activity. GC-FID analysis revealed the following major components (% w/w): cinnamon (cinnamaldehyde, 77.56%), ginger (α-zingiberene, 33.77%), geranium (citronellol, 33.6%), and tea tree (terpinen-4-ol, 38.38%). Dose–response data from essential oils tested against Detroit ATCC 551 skin fibroblasts revealed a clear cytotoxic hierarchy (IC₅₀ µg/mL): cinnamon (21.03) > ginger (25.3) > tea tree (41.67) > geranium (92.51). Cinnamaldehyde content was the primary contributor to photoprotective capacity, with a maximum sun protection factor (SPF) of 4.5. Inhibition against erythrocyte membrane lysis was not attributable to a single component; maximum protection (98.4%) was achieved through synergy between oxygenated monoterpenoids (geranium and tea tree), sesquiterpenes (ginger), and aromatic aldehydes (cinnamon). Highest catalase activity (160.86 kU/g Hb) was reached in mixtures with high cinnamaldehyde and eugenol contents, whereas an antagonistic effect was observed between tea tree and geranium oils. Finally, an optimal formulation (desirability = 0.927) was identified (% w/w): 31.7% ginger, 39.1% cinnamon, 14.5% tea tree, and 14.7% geranium. Experimental validation confirmed no significant difference compared with developed predictive models. This optimized mixture constitutes a bioactive natural component with potential for use in products aimed at promoting skin health, warranting further investigation into direct models of skin healing. Full article

Primary hepatocyte cultures serve as an ex vivo model of liver physiology. This study aims to employ poly(vinyl alcohol) (PVA) nanofiber membranes (NMs) to establish a three-dimensional (3D) culture system that supports the long-term functionality of primary hepatocytes. Primary hepatocytes were monocultured on a PVA NM or indirectly cocultured with NIH3T3 fibroblasts on a distinct polycaprolactone (PCL) NM layer. Monocultured and cocultured hepatocytes maintained prolonged survival without supplemental growth factors. Cocultured hepatocytes formed larger aggregates composed of cell clusters attached to untreated nanofibers than monocultured cells. However, most primary hepatocytes cultured on NaOH-treated PVA NM and Arg–Gly–Asp (RGD) peptide-blended PVA (RGD-PVA) NM, under monoculture and coculture conditions, formed non-aggregated cells in a single-cell layer. In a bioinert assay, unstimulated dendritic cells were activated on untreated but not NaOH-treated PVA NM. CYP3A4 activity was higher in cocultured cells on RGD-PVA NM with fibroblasts than in monocultured cells on PVA and RGD-PVA NM. Functional hepatocyte cultures were successfully maintained in a 3D single-cell layer on RGD-PVA NM, along with fibroblasts in a layer-by-layer coculture, for a prolonged period. The prolonged culture of hepatocytes in a 3D single-cell layer may facilitate further drug discovery, toxicity studies, and translational liver research. Full article

Photodynamic therapy (PDT) is a promising localized strategy for the treatment of cervical cancer, ranking as the fourth most common cancer among women worldwide. The integration of photosensitizers (PSs) in localized drug delivery systems (DDSs), particularly in electrospun nanofibers, holds tremendous potential to overcome the drawbacks of their systemic administration. Exploring multilayer fibrous architectures provides a versatile therapeutic platform to design the next generation of localized DDS. In this work, localized implants for cancer treatment using PDT were developed using polyhydroxyalkanoate (PHA), chitosan (CS) and polyethylene oxide (PEO) as biopolymers and a porphyrin (Por) as PS, following two approaches: blended PHA/Por electrospun microfibers and multilayered membranes (PHA–Por/CS/PEO) produced by sequential electrospinning. The synthesized Por displayed higher cytotoxicity in light compared to dark against tumor cells. All the developed membranes were characterized regarding their morphology, wettability, absorption and fluorescence properties. PHA–Por membranes exhibited overall uniform fibrous morphologies with successful Por incorporation. Nonetheless, they presented a highly hydrophobic surface, compromising the Por release and cell–material interactions. In contrast, multilayer PHA–Por/CS/PEO membranes demonstrated enhanced hydrophilicity and enabled sustained Por release. Upon light irradiation, these membranes induced a significantly greater inhibition of HeLa cell proliferation (29.61%) compared to dark conditions (6.21%), confirming their photodynamic activity. Full article

Carbon fiber-reinforced resin matrix composites (CFRC) are extensively used in aerospace, automotive manufacturing, and sports equipment. However, the brittle nature of the resin matrix causes CFRC to exhibit severe vibrations and noise under dry friction conditions. Enhancing the intrinsic damping properties of the resin matrix serves as a fundamental and effective strategy to mitigate vibration and noise radiation in composite components. This study systematically investigates high-temperature co-curing damping composites using co-curing technology, aiming to improve the mechanical performance and damping characteristics of traditional fiber-reinforced epoxy resin composites. A novel carbon fiber-reinforced terminal carboxyl nitrile epoxy pre-polymer composite material demonstrates both stable chemical properties and excellent high-temperature resistance. Through formulation adjustments, the curing temperature and time of epoxy resin are matched with those of the terminal carboxyl nitrile epoxy pre-polymer. The performance of epoxy carbon fiber composites was evaluated through tensile tests, flexural tests, impact tests, infrared spectroscopy, thermogravimetric analysis, dynamic mechanical analysis, scanning electron microscopy, and X-ray diffraction. Results show that blending epoxy resin with terminal carboxyl nitrile liquid rubber enhances energy dissipation by increasing intermolecular friction and hydrogen bonding interactions. The damping ratio of epoxy resin-based carbon fiber composites reaches as high as 1.67%. Tensile strength, flexural strength, and impact strength reach 1968 MPa, 1343 MPa, and 127 kJ/m², respectively. The addition of terminal carboxylated nitrile liquid rubber facilitates the formation of continuous friction membranes, enhancing friction stability. Tensile tests demonstrate that carbon fiber composites containing 25% terminal carboxylated nitrile liquid rubber outperforms other formulations. As evidenced by impact tests, the performance of the prepared composites is superior to that of other configurations. Dynamic mechanical analysis indicates that the 25% rubber-containing composites exhibit enhanced damping characteristics and higher loss modulus. Experimental results confirm that this study advances the development of functional composites for vibration reduction and noise control applications. Full article

This article delineates the electrical characteristics and usefulness of a plasticized polymer electrolyte (PPE) manufactured from PVDF/PEO blends, using varying weight percentages of the plasticizer ethylene carbonate (EC) in conjunction with a liquid electrolyte. Micro-porous solid-state polymer electrolyte membranes were fabricated using the non-solvent-induced phase separation (NIPS) method. The polymer composite membranes modified by the incorporation of a plasticizer (40 weight percent of EC) exhibited enhanced porosity and absorbed a significant quantity of liquid electrolyte (313.3%). A N₂ adsorption isotherm study indicates an increase in pore volume and pore size resulting from the incorporation of EC in PPE. This resulted in a satisfactory level of ionic conductivity (2.08 mS/cm) at 25 °C, attributable to the inclusion of 40 wt.% EC-based PPE, which has a high dielectric constant and a rapid relaxation time. The AC/40 wt.% EC-based PPE/LTO hybrid supercapacitor exhibits a superior specific capacitance, reduced internal resistance, and enhanced retention values after 10,000 cycles in comparison to the AC/10 wt.% EC-based PPE/LTO hybrid supercapacitor. Full article

Electromagnetic shielding (EMS) materials play an important role in modern technology and industry, especially in electronic equipment, communication technology, military applications and so on. With the continuous progress of technologies and the increasing demands for functional materials, EMS materials are expanding towards flexibility and being lightweight. Recently, metal–organic frameworks (MOFs) have garnered significant attention in the EMS field due to their unique structure and adjustable properties. In this paper, alloy-based porous nanospheres (CCZ-C) were fabricated by heat-treatment using CoCuZn-MOFs as precursors, and then electrospun CCZ-C/PVDF nanofiber membranes (NFMs) were prepared in a large-quantity by blending them with PVDF. Afterwards, a hierarchical porous structured NFM (MPPA) was obtained by loading a highly conductive Ag nanolayer on the surface of CCZ-C/PVDF nanofibers using pDA as a binder. By adjusting the CCZ-C content, it was determined that the EMS performance of MPPA was highest when the CCZ-C content was 2 wt.%, with an average SSE of 12,017.01 dB·cm²·g⁻¹. This was because the hierarchical porous structure formed by adding an appropriate amount of CCZ-C further improved the electromagnetic attenuation and impedance matching of MPPA. Full article

Polymeric microfiltration membranes are among the most utilized pressure-driven membranes due to their excellent permeation flux, moderate removal efficiency, low operating pressure, low cost, as well as their potential for reusability and cleanability. Therefore, these membranes are used in different crucial sectors, including the water and wastewater, dairy, beverage, and pharmaceutical industries. However, well-known polymeric microfiltration membranes suffer from their poor hydrophilic properties, causing fouling phenomenon. A reduction in permeate flux, a shortened operational lifespan, and increased energy consumption are the primary negative consequences of membrane fouling. Over the years, a broad spectrum of studies has been performed to modify polymeric microfiltration membranes to improve their hydrophilic, transport, and antifouling characteristics. Despite extensive research, this issue remains a subject of ongoing discussion and scrutiny within the scientific community. This review article provides promising information about different physical and chemical modification methods—such as polymer blending, the incorporation of nanomaterials, surface coating, chemical crosslinking, in situ nanoparticle immobilization, and chemical surface functionalization—for polymeric microfiltration membranes. The physical and chemical modification methods are comparatively evaluated, highlighting their positive and negative aspects, supported by findings from recent investigations. Moreover, promising ideas and future-oriented techniques were proposed to obtain polymeric microfiltration membranes containing superior efficiency, extended service life, and mechanical strength. Full article

In the context of climate change and the general trend toward a healthy lifestyle, reducing the alcoholic strength of wines poses a major challenge for producers. In order to obtain quality low-alcohol wines (LAWs), Muscat Ottonel conventional wine was subjected to reverse osmosis followed by vacuum concentration of the hydroalcoholic permeate (ROVC) or to two-step vacuum concentration (TSVC), with the recovery of aromas as the first alcoholic fraction (F1). Beverages with alcoholic concentrations of 3.50, 5.50, and 8.50% vol. were obtained, with compositional characteristics and sensory properties varying significantly with alcoholic strength and dealcoholization technique applied. ROVC produced wines with organic acids, volatile constituents, extract, and color intensity decreasing progressively with the reduction in alcohol concentration. At similar alcohol concentration, TSVC LAW showed a significantly higher phenolic content, antioxidant activity, volatile compounds (including esters and terpenes), and overall structural balance, maintaining better the typicity of wines. In both processes, reducing alcohol below 5.50% vol. significantly affected the quality and acceptability of the final product. Hierarchical cluster analysis indicated that TSVC LAWs were statistically closer to the conventional wine (control). These findings improve the understanding of how dealcoholization technologies affect the composition of wine, improving product quality, sustainability, and operational efficiency. Full article

Polysulfone (PSU) membranes are widely recognized for their thermal stability, mechanical strength, and chemical resistance, making them suitable for diverse separation applications. This review highlights recent advances in PSU membrane development, focusing on fabrication techniques, structural modifications, and emerging applications. Phase inversion remains the predominant method for membrane synthesis, allowing precise control over morphology and performance. Functional enhancements through blending, chemical grafting, and incorporation of nanomaterials—such as metal–organic frameworks (MOFs), carbon nanotubes, and zwitterionic polymers—have significantly improved gas separation, and water purification., In gas separation, PSU-based mixed matrix membranes demonstrate enhanced CO₂/CH₄ selectivity, particularly when integrated with MOFs like ZIF-7 and ZIF-8. In water treatment, PSU membranes effectively remove algal toxins and heavy metals, with surface modifications improving hydrophilicity and antifouling properties. Despite these advancements, challenges remain in optimizing cross-linking strategies and understanding structure–property relationships. This review provides a comprehensive overview of PSU membrane technologies and outlines future directions for their development in sustainable and high-performance separation systems. Full article

Developing cost-effective and durable electrocatalysts is essential for advancing anion exchange membrane fuel cells (AEMFCs). This work evaluates Pd-based catalysts supported on β-MnO₂, Vulcan carbon (C), and their physical blend (Pd/MnO₂:Pd/C) as bifunctional electrodes for the oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR). The catalysts were synthesized via chemical reduction and characterized by TGA, ICP-OES, TEM, BET, and XRD. Rotating disk electrode studies revealed that the hybrid exhibited superior activity and kinetics, with lower Tafel slopes and higher exchange current densities compared to the individual supports. In AEMFCs, the hybrid reached 128.0 mW cm⁻² as a cathode and 221.7 mW cm⁻² as an anode, outperforming individual components. This enhanced performance arises from the synergistic interaction between Pd nanoparticles and MnO₂, where MnO₂ modulates the catalyst’s microstructure and local reaction environment while the carbon phase ensures efficient electron transport. MnO₂, although inactive for the HOR alone, acted as a structural spacer, enhancing mass transport and stability. Durability tests confirmed that the hybrid electrocatalyst retained over 99% of its initial activity after 3000 cycles. These results highlight the hybrid Pd/MnO₂:Pd/C as a promising, bifunctional, and durable electrocatalyst for AEMFC applications. Full article

Sustainable membranes for efficient separation processes are increasingly necessary to counteract the significant environmental and human health impacts of manufacturing conventional membranes, which rely on synthetic polymers, toxic solvents, and harmful additives. A greener approach currently involves the use of bio-based polymers, blending synthetic polymers with biopolymers, utilizing nanocomposites, and greener solvents. Biopolymers are emerging as an environmentally friendly alternative for developing polymeric membranes due to their biological, biodegradable, recyclable, and biocompatible properties. However, the development of sustainable biopolymer-based membranes poses greater challenges to achieving a truly low environmental impact across all aspects of raw material production, manufacturing methods, operational systems, and waste disposal. Another challenge for its market competitiveness is achieving high functional and operational performance, wider applications, low commercial costs, and strong scale-up potential. This critical review assesses the current state of sustainability in membrane manufacturing based on recent literature. It also evaluates the role of biopolymers in sustainable membranes and discusses research opportunities in biopolymer production for membrane manufacturing, highlighting biotechnological tools, the circular economy and waste valorization. Full article

The study focused on essential oils (EOs) of plant origin, which are of great interest to scientists in the context of medical applications due to their biological properties, such as antimicrobial, anti-inflammatory, antioxidant, and anticancer effects. The objective of the study was to determine chemical profiles and biological activities of the essential oils extracted from five mixtures (M1 [Thymus vulgaris, Ammi visnaga, Syzygium aromaticum, Citrus sinensis]; M2 [Thymus vulgaris, Ammi visnaga, Cinnamomum verum, Citrus sinensis]; M3 [Mentha pulegium, Lavandula angustifolia, Zingiber officinale, Citrus sinensis]; M4 [Mentha pulegium, Lavandula angustifolia, Cinnamomum verum, Citrus sinensis]; M5 [Ammi visnaga, Lavandula angustifolia, Zingiber officinale, Syzygium aromaticum]). Each mixture was derived from a blend of four selected plants used in traditional medicine in Mostaganem, Algeria. When selecting the best composition, the interactions between plant components were considered in terms of potential therapeutic benefits. The chemical compositions of the EO mixtures were analyzed using GC-MS. The acute toxicity of the EO mixtures was evaluated in vivo following oral administration. The sensitivity of the microorganisms to the EO mixtures was determined using the agar diffusion method. Virucidal testing was performed using the quantitative suspension method to determine virucidal activity, as described in the European standard for disinfectants used in the medical field. The antioxidant activity of the EO mixtures was evaluated using a model membrane system based on liposomes derived from soybean phosphatidylcholine. Chemopreventive activity was assessed in vitro using cell culture. The main compounds identified were carvacrol and thymol in M1; geranial, cinnamylaldehyde, and carvacrol in M2; pulegone and limonene in M3; geranial and cinnamylaldehyde and limonene in M4; and eugenol and caryophyllene in M5. The selection of the “best” blend depended on the biological activity deemed most critical for the specific application. Specifically, M3, M4, and M5 exhibited the strongest anti-HSV-1, anti-HAdV-5, and anticancer activity, respectively. In contrast, M1, a potent antioxidant, demonstrated the strongest antibacterial and anticancer activity. These results indicate that M1, M3, M4, and M5 EOs have promising applications in the pharmaceutical industry and medical research. Full article