Search Results (311)

The growing demand for sustainable materials has led to increased interest in biodegradable polymer fibers and nonwoven mats due to their eco-friendly characteristics and potential to reduce plastic pollution. This review highlights how mechanical properties influence the performance and suitability of biodegradable polymer fibers across diverse applications. This covers synthetic polymers such as polylactic acid (PLA), polyhydroxyalkanoates (PHAs), polycaprolactone (PCL), polyglycolic acid (PGA), and polyvinyl alcohol (PVA), as well as natural polymers including chitosan, collagen, cellulose, alginate, silk fibroin, and starch-based polymers. A range of fiber production methods is discussed, including electrospinning, centrifugal spinning, spunbonding, melt blowing, melt spinning, and wet spinning, with attention to how each technique influences tensile strength, elongation, and modulus. The review also addresses advances in composite fibers, nanoparticle incorporation, crosslinking methods, and post-processing strategies that improve mechanical behavior. In addition, mechanical testing techniques such as tensile test machine, atomic force microscopy, and dynamic mechanical analysis are examined to show how fabrication parameters influence fiber performance. This review examines the mechanical performance of biodegradable polymer fibers and fibrous mats, emphasizing their potential as sustainable alternatives to conventional materials in applications such as tissue engineering, drug delivery, medical implants, wound dressings, packaging, and filtration. Full article

Three-dimensional printed polycaprolactone (PCL) tissue engineering scaffolds have drawn increasing interest from the medical industry due to their excellent biocompatibility and biodegradability, yet PCL’s poor mechanical performance has limited their applications. This study introduces a biocompatible and biodegradable polylactic acid (PLA) fiber reinforced PCL (PLA/PCL) composite as the filament for 3D printed scaffolds to significantly enhance their mechanical performance: Special-made PLA short fiber mat was infused with PCL matrix and rolled into PLA/PCL filaments through a “Vacuum Assisted Resin Infusion” (VARI) process. The investigation revealed that the PLA fibers are highly oriented along the printing direction when using this filament for 3D printing due to the unique microstructure formed during the VARI process. At the same PLA fiber content, the percentage increase in Young’s modulus of the 3D printed strands using the filaments produced by the VARI process is 127.6% higher than the 3D printed strands using the filaments produced by the conventional melt blending process. The 3D printed tissue engineering scaffolds using the PLA/PCL composite filament with 11 wt% PLA fiber content also achieved an exceptional 84.2% and 143.3% increase in peak load and stiffness compared to the neat PCL counterpart. Full article

In this work, the electrospinning technique was used to prepare novel polymeric composite fibers containing Te-doped bioactive glass powders. Bioactive glass powders containing tellurium (STe5 glass) were chosen as fillers for the composites, owing to their bioactive, antibacterial, and antioxidant properties. The biopolymer poly (ϵ-caprolactone) (PCL) and acetic acid (AA) were used as raw materials for the preparation of the polymeric matrix. FESEM analysis confirmed a good incorporation of the glass powders in the polymeric fibers, of up to 20% by weight. Wettability, mechanical, in vitro stability and preliminary antibacterial tests were also performed. The results showed that the treatment in AA did not affect the bioactivity of the glass powders, the presence of STe5 powders in PCL enhanced the wettability of the fibers, and mechanical properties improved by increasing the amount of STe5 powders, as well as the antibacterial effect. Therefore, the obtained materials appear promising for developing multifunctional composite materials for applications in tissue engineering. Full article

Background/Objectives: The work presented herein focused on the development and characterization of a transdermal caffeine platform fabricated from ultrathin micro- and submicron fibers produced via electrospinning. Methods: The formulations incorporated caffeine encapsulated in a polyethylene oxide (PEO) matrix, combined with various permeation enhancers. A backing layer made of annealed electrospun polycaprolactone (PCL) facilitated the lamination of the two layers to form the final multilayer patch. Comprehensive characterization was conducted, utilizing scanning electron microscopy (SEM) to assess the fiber morphology, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) for chemical detection and to assess the stability of the caffeine, and differential scanning calorimetry (DSC) along with wide-angle X-ray scattering (WAXS) to analyze the physical state of the caffeine within the fibers of the active layer. Additionally, Franz cell permeation studies were performed using both synthetic membranes (Strat-M) and ex vivo human stratum corneum (SC) to evaluate and model the permeation kinetics. Results: These experiments demonstrated the significant role of enhancers in modulating the caffeine permeation rates provided by the patch, achieving permeation rates of up to 0.73 mg/cm² within 24 h. Conclusions: This work highlights the potential of using electro-hydrodynamic processing technology to develop innovative transdermal delivery systems for drugs, offering a promising strategy for enhancing efficacy and innovative therapeutic direct plasma administration. Full article

The growing accumulation of plastic packaging waste poses severe environmental and health challenges. To address these issues, significant research has been devoted to developing biodegradable films; however, their weak mechanical and barrier properties limit their practical utility. This study introduces an innovative multilayer film production method, combining electrospun polycaprolactone (PCL) fibers with a chitosan matrix. Two configurations were investigated: (1) nonwoven PCL layers placed between chitosan sheets and (2) a chitosan sheet sandwiched between two nonwoven PCL layers. Both systems were evaluated using PCL fibers derived from medical-grade and technical-grade polymers. The chitosan/polycaprolactone/chitosan (CH/PCL/CH) configuration demonstrated superior performance, achieving enhanced interlayer cohesion and significantly improved mechanical strength, durability, and barrier properties. Notably, this configuration achieved tensile strength and elongation at break values of 57.1 MPa and 36.3%, respectively—more than double those of pure chitosan films. This breakthrough underscores the potential of multilayered biopolymer films as eco-friendly packaging solutions, offering exceptional promise for sustainable applications in the food packaging industry. Full article

Pelvic organ prolapse (POP) is a health condition that can significantly impact patients’ quality of life. Unfortunately, most available treatments present drawbacks such as high recurrence rates, risk of complications, poor tissue integration, and the need for reintervention. One promising alternative is the use of biodegradable implantable meshes, which can support the organs, guide tissue regeneration, and be fully absorbed without damaging the surrounding tissues. In this study, biodegradable polycaprolactone (PCL) meshes were fabricated using melt electrowritten (MEW), incorporating the antistatic agent Hostastat^® FA 38 (HT) to address these limitations. The goal was to produce microscaffolds with suitable biophysical properties, particularly more stable fiber deposition and reduced fiber diameter. Different HT concentrations (0.03, 0.06, and 0.1 wt%) were investigated to assess their influence on the fiber diameter and mechanical properties of the PCL meshes. Increasing HT concentration significantly reduced fiber diameter by 14–17%, 39–45%, and 65–66%, depending on mesh geometry (square or sinusoidal). At 0.06 wt%, PCL/HT meshes showed a 24.10% increase in tensile strength and a 55.59% increase in Young’s Modulus compared to pure PCL meshes of similar diameter. All formulations demonstrated cell viability >90%. Differential scanning calorimetry (DSC) revealed preserved thermal stability and changes in crystallinity with HT addition. These findings indicate that the antistatic agent yields promising results, enabling the production of thinner, more stable fibers with higher tensile strength and Young’s Modulus than PCL meshes, without adding cellular toxicity. Developing a thinner and more stable mesh that mimics vaginal tissue mechanics could offer an innovative solution for POP repair. Full article

This study consisted of the injection molding simulation of polycaprolactone (PCL)-based nanocomposites reinforced with multi-walled carbon nanotubes (MWCNTs) for biomedical implant manufacturing. The simulation was additionally supported by experimental validation. The influence of varying MWCNT concentrations (0.5%, 5%, and 10% by weight) on key injection molding parameters, i.e., melt flow behavior, pressure distribution, temperature profiles, and fiber orientation, was analyzed with SolidWorks Plastics software. The results proved the low CNT content (0.5 wt.%) to be endowed with stable filling times, complete mold cavity filling, and minimal frozen regions. Thus, this formulation produced defect-free modular filament sticks suitable for subsequent 3D printing. In contrast, higher CNT loadings (particularly 10 wt.%) led to longer fill times, incomplete cavity filling, and early solidification due to increased melt viscosity and thermal conductivity. Experimental molding trials with the 0.5 wt.% CNT composites confirmed the simulation findings. Following minor adjustments to processing parameters, high-quality, defect-free sticks were produced. Overall, the PCL/MWCNT composites with 0.5 wt.% nanotube content exhibited optimal injection molding performance and functional properties, supporting their application in modular, patient-specific biomedical 3D printing. Full article

This study focused on the preparation of poly(ε-caprolactone)/carbon nanotubes (PCL/CNTs) composite membranes via electrospinning technology and investigated their performance in oil–water separation. The effects of varying CNTs contents and spinning parameters on the structure and properties of the membrane materials were systematically studied. A highly uniform diameter distribution of the PCL fiber was achieved by using the dichloromethane/dimethylformamide (DCM/DMF) composite solvent with volume ratio of 7:3, as well as a PCL concentration of ca. 17 wt.%. The optimal electrospinning parameters were identified as an applied voltage of 18 kV and a syringe pump flow rate of 1 mL·h⁻¹, which collectively ensured uniform fiber morphology under the specified processing conditions. The critical threshold concentration of CNTs in the composite system was determined to be 1 wt.%, above which the composite fibers exhibit a significant increase in diameter heterogeneity. Both pristine PCL fibrous membranes and PCL/CNTs composite membranes demonstrated excellent and stable oil–water separation performance, with separation efficiencies consistently around 90%. Notably, no significant attenuation in separation efficiency was observed after ten consecutive separation cycles. Furthermore, when incorporating 0.5 wt.% CNTs, the PCL/CNT composite membranes exhibited a 20% increase in separation flux for heavy oils compared to pristine PCL membranes. Additionally, CNTs, as a prototypical class of nanofillers for polymer matrix reinforcement, can potentially enhance the mechanical properties of composite films, thus effectively prolonging their service life. Full article

Water contamination due to microbial proliferation remains a critical global challenge, especially with increasing urbanization, industrial activities, and the use of agrochemicals, and it requires the development of innovative methods for their purification that are not harmful to the environment and humans. In this study, innovative antibacterial nanocomposite coatings, composed of zirconia and silver nanocluster, were developed and deposited via eco-friendly co-sputtering physical vapor deposition (PVD) method onto electrospun polymeric membranes (PCL and PAN-PCL) for water filtration applications. Structural and morphological analyses, including XRD and UV-Vis spectroscopy, confirmed the deposition of a composite coating, consisting of an amorphous zirconia matrix embedding silver nanoclusters, homogeneously distributed on one side of the polymeric fibers. Wettability evaluations showed an increase in hydrophobicity after coating, particularly affecting the filtration performance of the PCL membranes. Antibacterial tests revealed strong inhibition against Staphylococcus epidermidis (Gram-positive) and partial efficacy against Escherichia coli (Gram-negative). Filtration tests of contaminated solutions revealed a 99% reduction in Bacillus subtilis, significant inhibition of Listeria monocytogenes, and limited effect on E. coli, with no bacterial proliferation observed on the coated membranes. These results underscore the effectiveness of ZrO₂/Ag nanocomposites in enhancing microbial control and suggest a promising, scalable strategy for sustainable and safe water purification systems. Full article

Bioactive glass (BG) is a promising material known for its osteogenic, osteoinductive, antimicrobial, and angiogenic properties. For this reason, melt-quench-derived BG powders embedded into composite electrospun poly(ε-caprolactone) (PCL) mats represent an interesting option for the fabrication of bioactive scaffolds. However, incorporating BG into nano-/micro-fibers remains challenging. Our research focused on integrating two BG compositions into the mat structure: 45S5 and 45S5_MS (the former being a well-known, commercially available BG composition, and the latter a magnesium- and strontium-enriched composition based on 45S5). Both BG types were added at concentrations of 10 wt.% and 20 wt.%. A careful grinding process enabled effective dispersion of BG into a PCL solution, resulting in fibers ranging from 500 nm to 2 µm in diameter. The mats’ mechanical properties were not hindered by the inclusion of BG powder within the fibrous structure. Furthermore, our results indicate that BG powders were successfully incorporated into the scaffolds, not only preserving their properties but potentially enhancing their biological performance compared to unloaded PCL electrospun scaffolds. Our findings indicate proper cell differentiation and proliferation, supporting the potential of these devices for tissue regeneration applications. Full article

Current hydrogels used for cartilage tissue engineering often lack the mechanical strength and structural integrity required to mimic native human cartilage. This study addresses this limitation by developing reinforced hydrogels based on a ternary polymer blend of poly(vinyl) alcohol (PVA), gelatin (GL), and chitosan (CH), with gentamicin sulfate (GS) as an antimicrobial agent and a crosslinker. The hydrogels were produced using two crosslinking methods, the freeze/thaw and heated cycles, and reinforced with forcespun polycaprolactone (PCL) nanofiber to improve mechanical performance. Chemical characterization revealed that GS forms weak hydrogen bonds with the ternary polymers, leading to esterification with PVA, and covalent bonds are formed as the result of the free amino group (-NH₂) of chitosan that reacts with the carboxylic acid group (-COOH) of gelatin. SEM images help us to see how the hydrogels are reinforced with polycaprolactone (PCL) fibers produced via force spinning technology, while mechanical properties were evaluated via uniaxial tensile and compressive tests. Water retention measurements were performed to examine the crosslinking process’s influence on the hydrogel’s water retention, while the hydrogel surface roughness was obtained via confocal microscopy images. A constitutive model based on non-Gaussian strain energy density was introduced to predict experimental mechanical behavior data of the hydrogel, considering a non-monotonous softening function. Loading and unloading tests demonstrated that GS enhanced crosslinking without compromising water retention or biocompatibility because of the reaction between the free amino group of CH and the carboxylic group of gelatin. The PCL-reinforced PVA/GL/CH hydrogel shows strong potential for cartilage repair and tissue engineering applications. Full article

In this study, novel biodegradable polycaprolactone (PCL)-based composites for sustainable packaging applications were developed by adding surface-treated wood fibers (WFs). Specifically, the WFs were treated with citric acid (CA) to improve the fiber/matrix adhesion and then melt compounded with a PCL matrix. The presence of an absorption peak at 1720 cm⁻¹ in the Fourier transform infrared (FTIR) spectra of CA-treated WFs, coupled with the increase in the storage modulus and complex viscosity in the rheological analysis, confirmed the occurrence of an esterification reaction between CA and WFs, with a consequent increase in interfacial interactions with the PCL matrix. Scanning electron microscopy (SEM) of the cryo-fractured surface of the composites highlighted that PCL was able to efficiently wet the fibers after the CA treatment, with limited fiber pull-out. Quasi-static tensile tests showed that the composites reinforced with CA-treated wood fibers exhibited a significant increase in yield strength (about 30% with a WF amount of 10% at 0 °C) and also a slight improvement in the VICAT softening temperature (about 6 °C with respect to neat PCL). Water absorption tests showed reduced water uptake in CA-treated composites, consistent with the reduced hydrophilicity confirmed by higher water contact angle values. Therefore, the results obtained in this work highlighted the potential of CA-treated WFs as reinforcement for PCL composites, contributing to the development of eco-sustainable and high-performance packaging materials. Full article

In atherosclerosis, the proliferation and migration of endothelial and smooth muscle cells (SMCs) and platelet activation alter endothelial function. Naturally occurring substances, such as caffeic acid (CA) and Trametes versicolor extract (TvE), have medicinal properties and are traditionally used for their antiproliferative, antioxidant, and anti-inflammatory effects. Electrospun 5% and 8% polycaprolactone-loaded CA or TvE was developed as a delivery system. Cytocompatibility was evaluated using human coronary artery endothelial cells (HCAECs), coronary artery SMCs (CASMCs), and platelets. Three types of systems (µF-CA, µF-TvE, and µF-CA/TvE) were developed and microscopically characterized. Analysis with scanning electron microscopy showed multidirectional fibers with diameters of 2–4.5 μm. The µF systems were hydrophobic and low cellular adhesion. The viability of CASMCs decreased with microfibers of 8% PCL and high CA concentration. However, the viability of CASMCs and HCAECs improved with 5% PCL and low CA concentration. Treatment with µF-TvE and µF-CA/TvE increased cell viability. HCAEC proliferation was affected by µF-CA, but incorporating TvE improved it. Platelet viability was unaffected by any µF system, but µF-CA and µF-CA/TvE inhibited the activation and adhesion of platelets. The results suggest that microfibers loaded with CA and TvE play a dual role in modifying HCAEC proliferation and blocking human platelet activation and adhesion. These findings have the potential to mitigate the atherosclerotic process. 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

Unlike the hot-melting processing of thermoplastic plastics, the processing of starch-based material relies on the addition of solvents, resulting in their low productivity, hindering large-scale industrialized production. A strategy to realize the high production efficiency of starch-based material, an environmentally friendly modification process without waste liquid generation, was designed to prepare a hot-melting starch (HMS) that can be repeatedly hot melted. Ball milling, enzymatic digestion, and deep eutectic solvent (DES) plasticization modification were combined to prepare the HMS. Ball milling destroyed the starch’s particles and the crystallinity, exposing the hydroxyl group, which allowed amylase to achieve enzymatic hydrolysis more easily. After enzymatic hydrolysis, the molecular chains of modified starch were shortened and the entanglement of molecular chains was reduced, which promoted the slip of molecular chains. The plasticization of DES, which promoted by the broken starch particles and the destroyed crystal structure, formed stronger hydrogen bonds and facilitated hot melting. Furthermore, due to the excellent hot-melting properties, HMS can be combined with sisal fiber and polycaprolactone (PCL) under solvent-free conditions. The tensile strength of HMS/sisal fiber/PCL was increased by 109%; meanwhile, the water contact angle was stabilized at 104°, when the blending ratio of hot-melting starch was 67.5% compared with HMS. Full article