Search Results (184)

Electrospinning is a highly versatile technique for fabricating nanofibrous membranes with high surface-area-to-volume ratios and tunable porosity. Although polycaprolactone (PCL) is widely utilized in biomedical engineering due to its biocompatibility, its electrospinning traditionally relies on hazardous organic solvents like dichloromethane (DCM) and N,N-dimethylformamide (DMF). This paper details the development of a fully sustainable, green electrospinning process for PCL using a bio-derived binary mixture of acetic acid and formic acid. Processing parameters (applied voltage, tip-to-collector distance, and flow rate) were systematically optimized using a Design of Experiments (DoE) response surface methodology. Scanning electron microscopy (SEM) confirmed the successful fabrication of uniform, bead-free nanofibers with a mean diameter of 247 nm, representing a 37.3% reduction compared to conventional DCM:DMF-spun matrices. Fourier-transform infrared spectroscopy (FTIR) verified complete solvent evaporates. Full article

Background: Thymoquinone (TQ), a bioactive compound derived from Nigella sativa L., exhibits promising antioxidant, anti-inflammatory, and wound-healing properties; however, its clinical application is limited by poor solubility and instability. Methods: In this study, three electrospun nanofiber systems based on different polymeric matrices, PVP (N1), PVP/HPβCD (N2), and PVP/PCL (N3), were developed as potential wound dressing materials for controlled TQ delivery. Results: All formulations produced uniform nanofibrous structures with TQ molecularly dispersed within the polymer matrix, as confirmed by SEM, XRPD, and FTIR analyses. The composition of the nanofibers significantly influenced their physicochemical and functional properties. The N2 system, containing hydroxypropyl-β-cyclodextrin (HPβCD), exhibited the smallest fiber diameter (~208 nm), the fastest drug release, and enhanced antioxidant and anti-inflammatory activity due to improved TQ solubility. In contrast, the N3 system, incorporating polycaprolactone (PCL), formed thicker fibers (~1089 nm) and demonstrated sustained release behavior, the highest mucoadhesion, and the most pronounced wound-healing effect (90% closure after 24 h). Stability studies revealed that HPβCD significantly improved TQ resistance to thermal, humidity, and photolytic degradation, whereas the PVP-based system without stabilizers showed the lowest stability. Principal component analysis (PCA) confirmed that nanofiber performance is governed by two key factors: drug availability and sustained release combined with bioadhesion. Importantly, wound-healing efficiency correlated more strongly with the latter. Conclusions: The results demonstrate that rational design of polymer composition enables modulation of TQ delivery and biological response. Among the tested systems, PVP/PCL nanofibers appear to be the most promising candidates for wound-dressing applications due to their ability to provide sustained drug release and enhance tissue regeneration. Full article

Polymer-based active packaging systems incorporating natural bioactive agents have attracted growing interest as eco-friendly alternatives to traditional food packaging materials. In this study, Pistacia lentiscus essential oil (PLEO) was incorporated into PCL/gelatin nanofibrous mats fabricated via solution blow spinning (SBS) to develop multifunctional and biodegradable active packaging materials. Neat PCL, gelatin-blended PCL (PCL–G) and PCL–G mats containing 5, 10 and 20 wt.% PLEO were produced and thoroughly analyzed for their morphological, chemical and functional characteristics. Morphological investigation revealed a smooth, bead-free fibrous structure in all samples. The average fiber diameter (AFD) increased from 239 nm to 320 nm with the addition of gelatin to the PCL matrix, while the incorporation of different concentrations of PLEO caused only minor changes. The results showed that as the concentration of PLEO increased, the antioxidant activity of the nanofibrous mats also increased. This enhancement is potentially linked to the rich content of bioactive molecules such as β-pinene, terpineol and verbenol. The 2,2-diphenyl-1-picrylhydrazyl scavenging activity improved from 6.4% (PCL) to 60% (PCL–G–20PLEO), and ABTS activity rose from 8.7% to 72%. In addition, antimicrobial evaluation showed inhibition zones of 12.5 mm against Escherichia coli and 14.2 mm against Staphylococcus aureus for the PCL–G–20PLEO nanofibrous mats. In 14-day storage tests on Kashar cheese, PCL–G–10PLEO and PCL–G–20PLEO mats reduced microbial counts by more than 2 log units compared with the control and effectively slowed yeast and mold growth. These findings confirm the potential of the PCL–G–PLEO nanofibrous mat as novel active packaging materials for preserving dairy products such as Kashar cheese. Full article

One-dimensional fibrous scaffolds with tunable bioactivity offer promise for bone tissue regeneration, yet optimal calcium phosphate phases for enhancing osteogenic performance remain underexplored. This study aimed to evaluate the impact of monetite-, brushite-, and cerium-doped phosphate deposition on electrospun nylon nanofibres functionalised via matrix-assisted pulsed laser evaporation (MAPLE). Five nylon fibre compositions were synthesised, coated with three calcium phosphate phases, and calcined at varying temperatures (500–800 °C) before laser deposition. Physicochemical properties were assessed using energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and fibre diameter measurements, averaging $62.1\pm 23.8$ nm. Biocompatibility assays following MC3T3 preosteoblast seeding and incubation evaluated biological performance. EDX confirmed homogeneous phase deposition; SEM showed phase- and temperature-dependent morphology, with monetite yielding uniform granular structures and cerium-doped phosphate at 800 °C forming dense aggregates. Brushite-coated fibres exhibited superior preosteoblast metabolic activity, reaching $178\pm 2\%$ after 48 h (p < 0.001), indicating phase-specific stimulation of bone cell growth. These phosphate-functionalised nylon fibres retain structural integrity, hierarchical porosity, and enhanced bioactivity, providing a versatile electrospinning-MAPLE platform for customisable bone grafts with clinical potential. Full article

This study investigates the impact of TiO₂ incorporation (0, 2, 4, 6, 8 wt.%) on the structural, optical, electrical, mechanical, and antibacterial properties of electrospun PVA/PVP nanofibers. FESEM observations revealed continuous, randomly oriented nanofibrous films with an average diameter in the 77–96 nm range, depending on TiO₂ content. FTIR and XRD analyses confirmed successful nanoparticle integration, showing effective interfacial interactions and the presence of crystalline TiO₂ phases within the semi-crystalline PVA/PVP matrix. Optical studies demonstrated a progressive decrease in the indirect band gap with increasing TiO₂ loading, decreasing from 3.75 to 3.54 eV according to the Tauc method and from 3.70 to 3.43 eV according to the ASF method, accompanied by an increase in Urbach energy from 0.43 to 0.64 eV, indicating enhanced structural disorder and tail state formation. The optical dispersion parameters obtained from the Wemple−DiDomenico model were consistent with these trends. Electrical characterization showed enhanced DC conductivity with increasing TiO₂ content and a marked reduction in thermal activation energy from 2.54 eV for the neat blend to 0.98 eV at higher TiO₂ loading, confirming facilitated charge transport in nanocomposite system. Mechanical characterization indicated that TiO₂ reinforcement improved both stiffness and strength, with the 6 wt.% sample achieving an optimal strength–ductility synergy (8.9 MPa and 121.5% elongation). Additionally, TiO₂ loading significantly boosted antibacterial performance, particularly against Escherichia coli and Staphylococcus aureus at 8 wt.%. These multifunctional properties position PVA/PVP:TiO₂ nanofibers as highly promising candidates for flexible biomedical coatings, optoelectronic devices, and advanced functional surfaces. Full article

Water contamination resulting from anthropogenic activities poses a critical threat to ecosystems and human health. The development of efficient, sustainable, and selective materials for water purification has therefore become a pressing necessity. In this study, polyurethanes (PUs) with tailored soft and hard segments were synthesized and characterized to evaluate their suitability for the fabrication of electrospun membranes. ATR-FTIR confirmed successful polymerization, while thermal analyses revealed that molecular design strongly influences the polymers’ thermal behavior. Among the synthesized materials, only two PUs exhibited solubility and spinnability, leading to homogeneous nanofibrous mats with average fiber diameters of approximately 500 nm. To enhance the adsorption capacity, specific surface area and interaction diversity of the membranes, metal–organic framework (MOF) particles were incorporated into the polymer solutions prior to electrospinning, allowing their immobilization within the fibrous polymer matrix. The resulting hybrid membranes showed remarkable improvements in methylene blue uptake, increasing from 29 to 34 mg·m⁻² in pristine membranes and 57 to 115 mg·m⁻² in the MOF-containing ones. This enhancement was attributed to the synergistic effect between the aromatic urethane structures and the MOF linkers, as well as to the increased effective surface area provided by the nanofibrous architecture. The results demonstrate the potential of electrospun PU-based membranes as pollutant removal, combining structural versatility, functional tunability, and compatibility. Full article

Background: Erectile dysfunction (ED) and premature ejaculation (PE) are prevalent conditions affecting men’s sexual health, for which tadalafil and dapoxetine have shown promise in their treatment, respectively. Conventional oral dosage forms face limitations, including variable absorption and delayed onset of action. In this study, we developed electrospun nanofibers using polyvinylpyrrolidone for buccal drug delivery as an alternative dosage form to oral tablets. This route offers advantages such as easy administration, suitability for those with difficulty swallowing, particularly the elderly, and a rapid onset of action via the blood capillaries, which might improve bioavailability. Methods: PVP nanofibers loaded with tadalafil and dapoxetine were fabricated using a modified electrospinning procedure with the Spraybase system, where an 8% (w/v) PVP ethanol solution containing 1.5% dapoxetine and 0.5% tadalafil was electrospun under controlled conditions (800 µL/h flow rate, 15 cm distance, 0.55 mm needle, and 8–10 kV) to produce uniform fibers. Results: The morphology of the nanofibers was characterized using SEM, revealing smooth, uniform fibers with an average diameter of 218 ± 50 nm for drug-loaded nanofibers. This nanofibrous system also demonstrated ultra-rapid disintegration occurring within 4 ± 1 s and consistent drug loading and encapsulation efficiency for both drugs. The release profile showed a burst drug release after 15 min, which accounted for >45% for tadalafil and >50% for dapoxetine, followed by a sustained increment in the drug release that reached > 60% for tadalafil and >78% for dapoxetine after 30 min until a complete drug release (100%) for both drugs after 180 min. In vitro cytotoxicity studies on human dermal fibroblasts confirmed the safety of both medications, with cell viability exceeding 50%, at concentrations of 1.56 to 25 µg/mL for tadalafil and 4.69 to 9.38 µg/mL for dapoxetine after 24 and 48 h of incubation. Conclusions: These findings highlight the potential of PVP-based nanofibers as a novel buccal delivery system for the combined treatment of ED and PE. Full article

Batch production of nanomaterials is highly desired for developing commercial nanoproducts. Here, a brand-new electrospinning method, termed hole electrospinning, was developed for batch production of drug-loaded polymeric nanofibers. Using resveratrol and polyvinylpyrrolidone as model drug and filament-forming matrix, respectively, both hole and single-needle electrospinning were conducted. The resultant nanofibrous films were compared in terms of morphology, physical and thermal properties, mechanical performance, fast-dissolution rate, and antioxidant activity. Analytical and characterization results verified that nanofibers from different processes showed no significant differences in morphology, diameter, porosity, tensile strength, amorphous state, fast-dissolution performance and antioxidant activity. However, hole electrospinning provided 13.3-fold higher productivity than single-needle electrospinning, better drug encapsulation efficiency (97.3 ± 4.5% versus 83.7 ± 6.1%), and higher energy efficiency (0.0393 W/g versus 0.1247 W/g). Based on the protocols reported here, not only was a batch nano-conversion method for polymeric engineering developed, but also an attractive approach for the large-scale production of various complex configurations was proposed for potential commercial nanostructure-based products. Full article

Background: Myricetin (MYR) is a natural flavonol with antioxidant, neuroprotective, anti-inflammatory, antidiabetic, and cardioprotective activities. Still, its pharmaceutical use is limited by very low aqueous solubility (~16.6 µg/mL) and poor oral bioavailability (<10%). This study aimed to enhance the solubility and potentially improve the bioavailability of MYR by developing an amorphous nanofibrous delivery system. Methods: Electrospinning was applied to fabricate MYR-loaded nanofibers using polyvinylpyrrolidone K30 (PVP30), and the influence of key processing parameters on MYR solubility was evaluated. Nanofibers produced under selected electrospinning conditions were characterized in terms of morphology, encapsulation efficiency, and physicochemical properties. Results: X-ray powder diffraction confirmed complete amorphization of MYR within the BB5 fiber structure (distance: 12 cm, voltage: 25 kV, flow rate: 1.5 mL/h). FTIR analysis indicated hydrogen-bonding interactions between MYR hydroxyl groups and PVP30 carbonyl groups, contributing to stabilization of the amorphous form. SEM images revealed homogeneous, defect-free fibers with diameters below 400 nm, although localized MYR agglomerates were observed. Solubility and release studies demonstrated a characteristic spring-and-parachute effect, enabling rapid MYR release and maintenance of a supersaturated state. Enhanced solubility resulted in significantly improved antioxidant activity in DPPH and CUPRAC assays compared with crystalline MYR. Conclusions: Electrospun PVP30 nanofibers represent a promising platform for improving the solubility, dissolution behavior, and functional activity of poorly soluble bioactive compounds such as myricetin, supporting their potential application in pharmaceutical formulations. Full article

This study reports the development and characterization of chitosan–poly(vinyl alcohol) (CH/PVA) nanofibers (NFs), functionalized with bioactive compounds (ACs) relevant for wound healing and tissue regeneration. CH/PVA NFs loaded with L-arginine (ARG), allantoin (ALA), royal jelly (RJ) and curcumin (CUR), either as single or co-loaded systems, were prepared by electrospinning. The polymer solutions were characterized in terms of key physicochemical properties relevant to electrospinning. The CH/PVA@ACs NFs were characterized morphologically and structurally through scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Additionally, surface-related, physical, and functional properties such as wettability, swelling behavior, and in vitro release profiles were examined. The NFs were successfully produced in a uniform and continuous manner, with the fiber diameter and morphology being influenced by the type of ACs. FTIR analysis validated the characteristic functional groups linked to both the polymeric matrix and ACs. The nanofibrous systems demonstrated a high swelling capacity and a release behavior that is dependent on pH. Analyses of surface free energy and wettability revealed favorable interfacial interactions between solid and liquid, indicating compatibility with aqueous biological environments. In summary, the developed CH/PVA@ACs NFs exhibited appropriate morphological, structural, surface, and functional properties, underscoring their potential as effective materials for wound dressings. Full article

The design of multifunctional biomaterials that offer both structural support and biochemical cues is essential for enhancing tissue regeneration. In this study, hybrid nanofibrous scaffolds composed of poly(L-lactide-co-ε-caprolactone) (PLCL) and bioactive factors secreted by Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) were fabricated via co-electrospinning. Nanofibers were produced in aligned and random configurations following an optimized protocol developed at the Institute for Bioengineering of Catalonia (IBEC). Their morphology and topography were characterized by light microscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM), and fiber orientation was quantified via Fast Fourier Transform (FFT) analysis. The scaffolds showed fiber diameters of 542.9 ± 62.3 nm, with aligned fibers predominantly oriented within 20° of the principal axis. Human AD-MSCs were used to assess biocompatibility and cell–material interactions. Aligned and random nanofiber architectures elicited distinct cellular responses. AD-MSCs on aligned fibers exhibited smaller spreading areas (~320 μm²) vs. on random nanofibers (~500 μm²) and substantially higher proliferation, resulting in a shorter cell-doubling time (~25 h) than those on random nanofibers (~130 h) or control substrates (~70 h). In addition, aligned nanofibers promoted markedly faster migration, reaching rates of ~5000 μm²/h surface coverage, compared with random nanofibers (~770 μm²/h) and controls (~1800 μm²/h). Together, the results show that nanofiber alignment and biochemical functionalization jointly influence MSC behavior and improve regeneration, highlighting the potential of these PLCL-based hybrid secretome/PLCL nanofibers for advanced wound healing. Full article

In this study, avocado seed (AS) waste was used as a feedstock for bacterial cellulose (BC) production. Global avocado consumption continues to rise due to its recognised health benefits, resulting in substantial amounts of waste generated by the avocado processing industry. This work proposes the efficient utilisation of avocado seed residues—rich in fermentable sugars—to enhance the economic viability of BC production while supporting responsible agro-industrial waste management. Hydrolysed avocado seeds were incorporated into a modified Hestrin–Schramm (MHS) medium for BC production using Komagataeibacter xylinus as the bacterial strain. The BC membranes obtained from the modified medium (BC-MHS) exhibited higher production (1.93 g/L) and productivity (0.19 g/L·day) compared with those produced in the standard HS medium (BC-HS). The morphology and nanofibre diameter (11–85 nm) of the resulting BC were not significantly affected; however, BC-MHS showed higher crystallinity (~78%) and a higher degradation temperature (~357 °C) than BC-HS. Conversely, the modified medium slightly reduced the mechanical performance of the BC in terms of elongation at break, tensile strength, and Young’s modulus. Overall, avocado seed waste was successfully transformed into a value-added material, demonstrating its potential for agro-industrial waste valorisation through scalable and sustainable biorefinery processes. Full article

Three-dimensional biomaterial scaffolds with controlled geometry and surface nanoarchitecture are essential for advancing polymer processing strategies in tissue engineering. Conventional electrospinning generates nanofibrous structures but has limited ability to reproduce defined three-dimensional shapes or achieve high pattern fidelity. This study aimed to develop a scalable processing method for producing biodegradable scaffolds with precisely controlled microstructure and geometry using phase separation–assisted electrospray. Poly (lactic acid) microcapsules with tunable diameters and porous nanofibrous surfaces were fabricated under controlled humidity and deposited onto conductive molds to obtain two- and three-dimensional scaffold shapes. The manufacturing process required only simple electrospray equipment and static molds, without mechanically complex collectors or moving stages. The resulting scaffolds replicated mold features with resolutions down to 200 μm and achieved thickness up to 600 μm. The nanofibrous microcapsule surfaces supported strong adhesion and metabolic activity of HepG2 cells, while cellular penetration into deeper scaffold regions remained limited to approximately 80 μm. These findings indicate that electrospray-mediated microcapsule deposition is a practical polymer-processing approach that integrates nanofibrous surface formation with mold-defined shaping, offering a reproducible and scalable method for fabricating structurally precise and biologically compatible three-dimensional scaffolds. Full article

Fine and ultra-fine sugarcane bagasse (SCB) fractions (≤200 μm) that are naturally generated during industrial grinding have been systematically overlooked in lignocellulosic pretreatment research. Previous studies have largely relied on commercially processed pulps or coarse particles (>200 μm), typically without systematic size fractionation. Here, we demonstrate that these fine fractions—including ultra-fines (≤45 μm), which are often excluded from analytical workflows due to concern about excessive degradation—are viable feedstocks for producing lignin-containing cellulose nanofibers (LCNF) via a sequential thermal hydrolysis treatment (THT)–deep eutectic solvent (DES) pretreatment specifically designed to retain lignin. Size-fractionated SCB (≤45, 45–100, and 100–200 μm) was subjected to THT (190 °C, 15 min), followed by DES treatment using choline chloride/urea (1:2 molar ratio, 130 °C, 2 h). Multi-technique characterization using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) indicated substantial hemicellulose removal (>70%), effective lignin retention (7.6–9.1%), cellulose enrichment (74.0–77.5%), and preservation of cellulose I structure allomorph. The crystallinity index increased from 46.5–52.7% after THT to 56.7–57.2% after DES treatment, and notably, uniform compositional and structural features were obtained across all particle size classes after DES treatment. Subsequent high-pressure microfluidization (700 bar, five passes) yielded LCNF with consistent morphology across all fractions: uniform fibril diameters (24.6–26.2 nm), a discernible lignin coating, and excellent colloidal stability (zeta potential: −86.3 to −95.0 mV). Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) confirmed well-dispersed nanofibrous networks. Collectively, these findings show that the full range of fine SCB fractions can be effectively valorized into high-performance LCNF through sequential THT–DES pretreatment, enabling comprehensive utilization of industrial grinding outputs and advancing circular bioeconomy objectives. Full article

The development of membranes and patches for controlled drug release to enhance therapeutic efficacy is a promising approach to addressing the challenge posed by poor adherence to pharmacological therapies for chronic diseases. In this study, we designed an electrospun polycaprolactone (PCL) nanofibrous membrane reinforced with different concentrations (0.04%, 0.05%, 0.075%, and 0.2%) of functionalized multi-walled carbon nanotubes (f-MWCNTs) intended for biomedical applications, such as transdermal devices. We characterized the resulting composites using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and dynamic mechanical analysis (DMA) to evaluate their morphology, chemical composition, and mechanical properties. We also measured their cytotoxicity upon contact with peripheral blood mononuclear cells. The nanofibers had diameters below 100 nm and inclusions of microspheres, which were attributed to the electrospinning expansion phenomenon. Spectroscopic and mechanical analyses confirmed molecular interactions between the PCL matrix and the f-MWCNTs. Finally, biological tests demonstrated that both the dispersion of f-MWCNTs and the nanofiber sizing render the membranes biocompatible, supporting their potential use as drug-delivery systems. Full article