Search Results (175)

This study aimed to fabricate an active film incorporating limonin (LM) and resveratrol (RES) within a zein/shellac (ZS) matrix for use in strawberry preservation. Zein/shellac composite films embedded with varying concentrations of LM (0–4% w/w) and RES were successfully fabricated using coaxial electrospinning. The prepared films were comprehensively characterized for their mechanical properties, water vapor permeability (WVP), antioxidant capacity (DPPH, ABTS, FRAP), and antibacterial efficacy against E. coli and S. aureus. Mechanical properties and WVP results revealed that the ZSLM4R film exhibited an elongation at break (EBA) of 28.91%, tensile strength (TS) of 0.93 MPa, elastic modulus (EM) of 40.76 MPa, and a WVP of 1.55 g mm/m². h. kPa. Furthermore, LM and RES increased the antioxidant properties of the composite film. ZSLM4R’s free radical scavenging activities against DPPH and ABTS were 68.14% and 89.69%, respectively. The composite film also demonstrated strong antibacterial efficacy against E. coli and S. aureus. When applied to strawberries, ZSLM4R packaging effectively extended the fruit’s shelf life compared to the unwrapped and commercial polyethylene (PE) controls. These obtained results indicate that LM/RES-incorporated zein/shellac composites are a promising eco-friendly packaging alternative for preserving perishable fresh produce and extending its shelf life. Full article

Gas-assisted coaxial electrospinning (GACES), a simple and versatile technique for the large-scale fabrication of coaxial nanofiber membranes, possesses significant industrial potential across advanced manufacturing sectors including semiconductors—particularly for fabricating high-precision dielectric layers, high-uniformity encapsulation materials, and flexible semiconductor substrates requiring tailored core-shell architectures. However, there is still a lack of relevant studies on the effective regulation of the core-shell structures of coaxial fibers based on GACES, which greatly limits the batch preparation and wide application of coaxial fibers. Finite element simulation analysis of the flow field and development of the coaxial jet mechanics model with a gas-driven flow field—two key methodologies in this study—successfully uncovered the influence mechanism of gas-assisted flow fields on the core-shell structures of coaxial nanofibers. By adjusting the gas-assisted flow fields parameters, we reduced the total diameter of coaxial fibers by 47.33% (average fiber diameter: 334.12 ± 16.29 nm → 175.98 ± 1.18 nm), decreased the shell thickness by 72.98%, increased the core-shell ratio by 289% (core-shell ratio: 0.49 → 1.91), and improved the uniformity of the total diameter distribution of coaxial fibers by 30.64%. This study delivers a practical conceptual framework and robust experimental underpinnings for the scalable fabrication of coaxial nanofiber membranes with controllable core-shell structures, thereby promoting their practical application in semiconductor devices such as ultra-thin dielectric layers, precisely structured encapsulation materials, and high-uniformity templates for nanoscale circuit patterning. Full article

In this work, hollow-structured nanofibers with densely and uniformly distributed ZnO nanorods were successfully prepared by a combination of coaxial electrospinning, heat treatment, and hydrothermal synthesis, exhibiting excellent photocatalytic degradation performance. The morphological and structural characteristics of hollow ZnO nanofibers obtained at different heat treatment temperatures were systematically investigated, and their photocatalytic degradation performances were compared through degrading methylene blue (MB) under ultraviolet (UV) irradiation. It was found that the hollow ZnO nanofibers obtained by heat treatment at 280 °C exhibited the best photocatalytic degradation performance due to their optimal morphology and structure. Their photocatalytic degradation efficiencies for MB under 3 h of UV light and natural sunlight were 94.70% and 92.95%, respectively. Furthermore, cyclic stability tests were conducted on the optimal sample, revealing that its degradation efficiency remained at 89.96% after three cycles, demonstrating its excellent reusability. Full article

Antimicrobial function in protective and medical textiles is an essential safety feature since textiles can become breeding grounds for microorganisms. Ideally, the antimicrobial function in textiles should be non-toxic, stable, and durable. This study explores a core–shell nanofiber with a core of the cationic biopolymer ε-poly-L-lysine (PL) and shell of structurally similar and biocompatible polyamide-6 (PA). The core–shell structure is expected to have a more stable antimicrobial function than its monolithic counterpart. Further, thermal crosslinking is expected to prevent rapid diffusion of the water-soluble PL. Therefore, this study establishes a comparison between a monolithic (control), a core–shell (CS), and a thermally crosslinked core–shell (CL-CS) nanofiber of PL and PA. Morphological analysis confirmed the successful generation of the core–shell nanofibers. All the samples exhibited hydrophilic behavior and antimicrobial function. However, the control sample showcased significantly reduced zones of inhibition in antimicrobial testing with 21 days of bacterial exposure (1.027 ± 0.072 cm²), as compared to 24 h bacterial exposure (1.347 ± 0.151 cm²). On the other hand, the zones of inhibition for 24 h vs. 21 days for CS (1.265 ± 0.042 cm² vs. 1.052 ± 0.235 cm²) and CL-CS (1.128 ± 0.161 cm² vs. 1.106 ± 0.047 cm²) showed no significant differences. Therefore, the core–shell structure allowed for sustainable and durable antimicrobial action. Lastly, the CL-CS sample exhibited reusable antimicrobial function owing to the core–shell structure paired with thermal crosslinking. This study showcases a fiber system with non-toxic, durable, and reusable antimicrobial function. This study builds grounds for the development and multifaceted holistic characterization of safe, stable, and scalable antimicrobial textiles. Full article

Triaxial electrospinning was used to fabricate fiber membranes composed of polycaprolactone (PCL), poly(lactic-co-glycolide) (PLGA), and gelatin (GT), designed as carriers for curcumin (Cur) delivery. Here, synthetic polyesters acted as core and shell layers, while GT formed the middle layer containing Cur at varying concentrations. This paper aimed to demonstrate the effect of a shell layer by rearranging the core and shell layers on the kinetics of model drug delivery. In vitro release results indicated the shell layer considerably affected the release behavior, reducing the initial burst release by up to 28% in triaxial fibers compared to coaxial fibers in PLGA-shell forms. The release kinetics were interpreted using the Gallagher–Corrigan model. The membranes were also evaluated for their morphological properties. PLGA-shell-layered triaxial fibers exhibited pore sizes up to approximately 11 µm, small enough to prevent cell migration, while providing higher permeability. The surface wettability analysis of the developed fibers showed that all forms exhibited hydrophilic properties. Furthermore, the cytocompatibility of the fiber membranes was confirmed with the relative cell viability of over 80%. Triaxial fibers with different shell layers displayed similar release trends, yet fibers with the PLGA shell layer demonstrated more favorable performance, attributed to its layer configuration. These findings suggest that the strategic positioning of polymers in triaxial electrospun membranes could be pivotal in optimizing drug delivery systems. Full article

Background/Objectives: Skin wounds interrupt the natural anatomy and function of the skin. The body passes through four physiological phases to repair wounds after injury. Since the fibers are more closely related to the extracellular matrix structure, they can be used as scaffolds to accelerate wound closure. Shikonin is a botanical herbal remedy used as an anti-inflammatory agent and for its wound-healing characteristics. Cresols are known for their bactericidal and fungicidal properties, which promote their utilization as a disinfectant in soap. Therefore, this study aimed to formulate shikonin and cresol-loaded nanofibers for a dual wound-healing and antibacterial wound dressing in vitro. Methods: This study demonstrated the effectiveness of the drug-loaded nanofibers against diverse Gram-positive and Gram-negative bacteria using the minimum inhibitory concentration (MIC) and zone of inhibition assays. Results: Scanning electron microscopy images showed successful formulation of shikonin/cresol fibers with an average diameter of 772 ± 152 nm. The encapsulation efficiency and drug loading for the dual drug-loaded fibers were 44 ± 1% and 25 ± 1 µg/mg, respectively, for shikonin, and 38 ± 1% and 21 ± 0.5 µg/mg, respectively, for cresol, with a full release of both drugs achieved after 180 min. The combination of both compounds exhibited a safe concentration of ≤6 µg/mL, with cell viability of >50% in human dermal fibroblasts (HFF-1) after 24 h. The MIC results indicated that the combination was efficient as an antibacterial agent against Gram-positive bacteria at a safe concentration. The shikonin/cresol-loaded fibrous system showed an inhibition zone close to that of the control drugs, suggesting that the drugs have retained their antibacterial activity after electrospinning. Conclusions: This dual drug-loaded fiber system showed a high potential as an antibacterial wound dressing for skin infection injuries. However, in vivo studies are required to assess the safety and efficacy in an animal model of the dual drug-loaded fiber system. Full article

Emerging organic contaminants (EOCs), including polychlorinated bisphenyls (PCBs), pharmaceuticals, personal care products, pesticides, polycyclic aromatic hydrocarbons (PAH), and dyes, are among the most hazardous pollutants found in water bodies and sediments. These substances pose serious threats to the environment and human health due to their high toxicity, long-range mobility, and bioaccumulation potential. Although various methods for degradation of organic pollutants exist, photocatalysis using ultraviolet (UV) and visible light (VIS) has emerged as a promising approach. However, its practical applications remain limited due to challenges such as the use of powdered photocatalysts, which complicates their removal and recycling in industrial settings, and the restricted solar availability of UV light (~4% of the solar spectrum). This review investigates the effectiveness of hybrid electrospun conductive polymer nanofibers on metal oxide photocatalysts such as TiO₂ and ZnO (including doped and co-doped forms) and fabricated via mono- or coaxial electrospinning, in the degradation of EOCs in water under visible light. Furthermore, strategies to enhance the fabrication of these hybrid electrospun conductive nanofibers as visible-light-responsive photocatalysts, such as the inclusion of dopants and/or plasmonic materials, are discussed. Finally, the current challenges and future research directions related to electrospun nanofibers combined with photocatalysts for the degradation of EOCs in water treatment applications are outlined. Full article

Background: Although electrohydrodynamic atomization (EHDA) consistently provides drug-encapsulation efficiencies (DEE) far above those of conventional bottom-up nanotechnologies, the question of how to systematically push that efficiency even higher remains largely unexplored. Methods: This study introduces a modified triaxial electrospinning protocol tailored to the application and benchmarks it against two conventional techniques: single-fluid blending and coaxial electrospinning. Ethylcellulose (EC) served as the polymeric matrix, while curcumin (Cur) was chosen as the model drug. In the triaxial setup, an electrospinnable, drug-free EC solution was introduced as an intermediate sheath to act as a molecular barrier, preventing Cur diffusion from the core fluid. Ethanol alone was used as the outermost fluid to guarantee a stable and continuous jet. Results: This strategy provided a DEE value of 98.74 ± 6.45%, significantly higher than the 93.74 ± 5.39% achieved by coaxial electrospinning and the 88.63 ± 7.36% obtained with simple blending. Sustained-release testing revealed the same rank order: triaxial fibers released Cur the most slowly and exhibited the smallest initial burst release effect, followed by coaxial and then blended fibers. Mechanistic models for both fiber production and drug release are proposed to clarify how the tri-layer core–shell structure translates into superior performance. Conclusions: The modified triaxial electrospinning was able to open a new practical route to produce core-sheath nanofibers. These nanofibers could provide a higher DEE and a better sustained drug release profile than those from the coaxial and blending processes. Full article

Hollow coaxial double-shell submicron fibers were fabricated by combining electrospinning and atomic layer deposition (ALD). Polyvinyl alcohol (PVA) fibers were electrospun to serve as templates for the subsequent atomic layer deposition (ALD) of ZnO doped with transition metals (TM: Ni, Co, and Fe). An inner shell of amorphous Al₂O₃ was first deposited at low-temperature ALD to protect the polymer template. The PVA core was then removed through high-temperature annealing in air. Finally, a top shell of TM-doped ZnO was deposited at an elevated temperature within the ALD window for ZnO. The morphology, microstructure, elemental composition, and crystallinity of these submicron hollow double-shell fibers were thoroughly investigated using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Full article

Co-axial electrospinning is one of the facile methods for the fabrication of core–shell metal oxides for environmental applications. Indeed, core–shell architectures featuring a magnetic core and a photocatalytic shell represent a novel approach to catalytic nanostructures in applications such as water treatment and pollutant removal via magnetic separation. This study focuses on the fabrication of novel Fe₃O₄-Fe₂NiO₄/NiO core–shell nanofibers with enhanced optical and magnetic properties using co-axial electrospinning. The aim is to optimize the fabrication parameters, particularly the amount of metal precursor in the starting solutions, to achieve well-defined core and shell structures (rather than single-phase spinels), and to investigate phase transitions, structural characteristics, as well as the optical and magnetic properties of the resulting nanofibers. Raman, XRD, and XPS results show several phases and high defect concentration in the NiO shell. The Fe₃O₄-Fe₂NiO₄/NiO core–shell nanofibers exhibit strong visible-light absorption and significant magnetization. These advanced properties highlight their potential in photocatalytic applications. Full article

To address mass transport limitations in carbon nanofiber membrane electrodes for overall water splitting, a self-supporting nitrogen-doped hollow carbon nanofiber membrane embedded with Co/Co₂P heterojunctions (Co/Co₂P-NCNFs-H) was fabricated via continuous coaxial electrospinning. The architecture features uniform hollow channels (200–250 nm diameter, 30–50 nm wall thickness) and a high specific surface area (254 m² g⁻¹), as confirmed by SEM, TEM, and BET analysis. The Co/Co₂P heterojunction was uniformly dispersed on nitrogen-doped hollow carbon nanofibers through electrospinning, leverages interfacial electronic synergy to accelerate charge transfer and optimize the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Electrochemical tests demonstrated exceptional catalytic activity, achieving current densities of 100 mA cm⁻² at ultralow overpotentials of 405.6 mV (OER) and 247.9 mV (HER) in 1.0 M KOH—surpassing most reported transition metal catalysts for both half-reactions. Moreover, the electrode exhibited robust long-term stability, maintaining performance for nearly 20 h at 0.6 V (vs. Ag/AgCl) (OER) and over 250 h at −1.5 V (vs. Ag/AgCl) (HER), attributed to the mechanical integrity of the hollow architecture and strong metal–carbon interactions. This work demonstrates that integrating hollow nanostructures (enhanced mass transport) and heterojunction engineering (optimized electronic configurations) creates a scalable strategy for designing efficient bifunctional catalysts, offering significant promise for sustainable hydrogen production via water electrolysis. Full article

Dicyclopentadiene (DCPD)–poly(methyl methacrylate) (PMMA) core–shell fibers were fabricated via coaxial electrospinning to develop a self-healing polymer composite. A PMMA shell containing a first-generation Grubbs catalyst was co-spun with a DCPD core at 0.5 mL h⁻¹ and 28 kV, yielding smooth, cylindrical fibers. The diameter range of nanofibers was 300–900 nm, with 95% below 800 nm, as confirmed by FESEM image analysis. FTIR spectroscopy monitored shell integrity via the PMMA C=O stretch and core polymerization via the trans-C=C bands. The high presence of the 970 cm⁻¹ band in the healed nanofiber mat and the minor appearance in the uncut core–shell mat demonstrated successful DCPD polymerization mostly where the intended damage was. The optical clarity of PMMA enabled the direct monitoring of healing progress via optical microscopy. The presented findings demonstrate that PMMA can retain a liquid active core and catalyst to form a polymer layer on a damaged site and could be used as a model material for other self-healing systems that require healing monitoring. Full article

The electrospinning technique can produce multifunctional polymeric devices by forming solid fibers from polymer solutions under a high-voltage electric field. Variations such as concentric needles yield core/shell fibers. This study evaluates the effects of applied voltage (12.5–20 kV) and tip-to-collector distance (12.5–20 cm) on the morphology and thermochemical behavior of PLGA/PVA fibers made by coaxial electrospinning compared with casting-produced membranes and monolithic fibers. Optimal coaxial fibers (597 ± 90 nm diameter) were produced at 15 cm/12.5 kV, exhibiting a well-defined core/shell structure (PVA core: ~100 nm; PLGA shell: ~50 nm) confirmed by laser scanning confocal (core solution labeled with fluorescein) and TEM. FTIR and TGA demonstrated nearly complete solvent removal in electrospun samples versus ~10% solvent retention in cast films. XRD analysis indicated that cast films (PLGAff) exhibited minimal crystallinity (Xc ≈ 0.1%), while electrospun PLGA (PLGAe) showed cold crystallization and higher crystallinity (Tcc ≈ 90.6 °C; Xc ≈ 2.45%). DSC detected two different Tg (≈43.2 °C and 52.8 °C) in the coaxial fibers, confirming distinct polymer domains with interfacial interactions. These results establish precise processing/structure relationships for defect-free coaxial fibers and provide fundamental design principles for hybrid systems in controlled drug delivery and tissue engineering applications. Full article

The intrinsic trade-off among sensitivity, response speed, and measurement range continues to hinder the wider adoption of flexible pressure sensors in areas such as medical diagnostics and gesture recognition. In this work, we propose a grid-structured polycaprolactone/thermoplastic-polyurethane nanofiber pressure sensor decorated with multi-walled carbon nanotubes (PCL/TPU@MWCNTs). By introducing a gradient grid membrane, the strain distribution and reconstruction of the conductive network can be modulated, thereby alleviating the conflict between sensitivity, response speed, and operating range. First, static mechanical simulations were performed to compare the mechanical responses of planar and grid membranes, confirming that the grid architecture offers superior sensitivity. Next, PCL/TPU@MWCNT nanofiber membranes were fabricated via coaxial electrospinning followed by vacuum-filtration and assembled into three-layer planar and grid piezoresistive pressure sensors. Their sensing characteristics were evaluated by simple index-finger motions and slide the mouse wheel identified. Within 0–34 kPa, the sensitivities of the planar and grid sensors reached 1.80 kPa⁻¹ and 2.24 kPa⁻¹, respectively; in the 35–75 kPa range, they were 1.03 kPa⁻¹ and 1.27 kPa⁻¹. The rise/decay times of the output signals were 10.53 ms/11.20 ms for the planar sensor and 9.17 ms/9.65 ms for the grid sensor. Both sensors successfully distinguished active index-finger bending at 0–0.5 Hz. The dynamic range of the grid sensor during the extension motion of the index finger is 105 dB and, during the scrolling mouse motion, is 55 dB, affording higher measurement stability and a broader operating window, fully meeting the requirements for high-precision hand-motion recognition. Full article

Gene therapy, which treats genetic diseases by fixing defective genes, has gained significant attention. Viral vectors show great potential for gene delivery but face limitations like poor targeting, uncontrolled release, and risks from high-dose delivery which can lower efficiency and trigger immune responses. Loading viral vectors onto tissue engineered scaffolds presents a promising strategy to address these challenges, but their widespread application remains limited due to concerns regarding viral vector bioactivity, scaffold biocompatibility, and the stability of sustained release. An adeno-associated virus (AAV), recognized for its safety, high efficiency, and low immunogenicity, was employed as a model virus. In this study, we developed an electrospun scaffold (AAV/PCL-PEO@Co-ES) by encapsulating the AAV within core–shell fibers composed of polycaprolactone (PCL) and polyethylene oxide (PEO) via coaxial electrospinning. This configuration ensures viral vector protection while enabling controlled and sustained release. The physicochemical characterization results indicated that the scaffold exhibited excellent mechanical properties (tensile strength: 3.22 ± 0.48 MPa) and wettability (WCA: 67.90 ± 8.45°). In vitro release and cell transduction assays demonstrated that the AAV-loaded scaffold effectively controls viral vector release and transduction. Furthermore, both in vitro and in vivo evaluations demonstrated good biocompatibility and efficient viral vector delivery. These findings highlight the potential of the AAV/PCL-PEO@Co-ES scaffold as a safe and effective platform for sustained gene delivery, offering valuable insights for the future design of clinically relevant viral vector delivery systems. Full article