Search Results (245)

Hydrophilic surface modification is widely investigated as a strategy to improve the hemocompatibility of small-diameter vascular grafts. We previously developed a polyvinyl alcohol-coated poly-ε-caprolactone nanofiber graft (PVA–PCL graft) and showed that the PVA coating improved graft hydrophilicity and mechanical properties. However, whether this coating provides an in vivo advantage over uncoated PCL grafts remains unclear. In addition, the influence of pre-implantation surface hydration on the function of hydrophilic grafts has not been fully examined. In this study, we first compared PVA–PCL and uncoated PCL grafts in a rat abdominal aorta implantation model and found no statistically significant difference in patency rate between the graft types. We then examined whether pre-wetting enhanced the anti-fouling function of the PVA coating. In vitro whole-blood flushing assays demonstrated that pre-wetting markedly reduced blood component deposition on PVA–PCL grafts, but this effect did not translate into detectable improvements in patency or tissue regeneration in the rat model. These findings indicate that pre-wetting effectively enhances the in vitro anti-fouling behavior of PVA–PCL grafts and may serve as a simple strategy to optimize the functional surface state of hydrophilic coatings. Further studies are needed to determine whether this in vitro improvement can be translated into meaningful enhancement in graft performance in vivo. Full article

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

Diabetic chronic wounds are often accompanied by excessive wound exudate maceration, which prolongs the inflammatory phase and increases the risk of infection. Such a complex wound microenvironment imposes more stringent requirements on multifunctional wound dressings. A multifunctional Cur Janus nanofibrous dressing is developed by integrating an electrospun poly(ε-caprolactone)/gelatin hydrophilic layer with a curcumin (Cur)-loaded PCL hydrophobic layer. Janus structure with asymmetric wettability, which exhibited unidirectional liquid transport properties both in vitro and in vivo. Its unique structure also makes it possible to carry both hydrophilic and hydrophobic drugs at the same time. The incorporation of curcumin endows the dressing with antibacterial and antioxidant functionalities, offering the potential to modulate the inflammatory microenvironment of diabetic chronic wounds. Furthermore, the wound healing ability and anti-inflammatory effects of Cur Janus nanofibers were evaluated in a diabetic mouse model. The results showed that Cur Janus nanofibers significantly reduced wound area, increased the proportion of pro-healing M2 macrophages, shortened the inflammatory phase, and ultimately accelerated diabetic wound healing. This work provides a multifunctional and scalable platform for advanced wound dressing design. Its excellent antibacterial, antioxidant (ROS scavenging) and anti-inflammatory (macrophage phenotype M1 to M2) properties, combined with the unidirectional fluid transport and dual-release potential of hydrophilic and hydrophobic drugs, demonstrate broad prospects in the management of diabetic wounds. 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

Background/Objectives: Wound infections represent a major clinical challenge due to their polymicrobial nature, biofilm formation, and increasing antimicrobial resistance, which compromise conventional treatments. This study aimed to develop and evaluate ligand-stabilized silver nanoparticles (AgNPs) with improved antimicrobial activity and cytocompatibility, and to investigate their incorporation into electrospun nanofibers for wound management. Methods: Four AgNP formulations stabilized with citrate, cysteine, ketorolac, and diclofenac were synthesized via chemical reduction. Physicochemical characterization included surface plasmon resonance and zeta potential measurements. Antimicrobial activity was assessed through minimum inhibitory concentration (MIC) and bactericidal assays against Gram-positive, Gram-negative, and fungal strains. Toxicity was evaluated using the HET-CAM assay, while cytocompatibility was determined in fibroblasts, MG-63 cells, and mesenchymal stem cells. Diclofenac-stabilized AgNPs were incorporated into electrospun PCL/PEO nanofibers to generate a functional nanocomposite system. Results: All AgNPs exhibited a characteristic SPR at ~400 nm and high colloidal stability. Diclofenac-stabilized AgNPs (dc-AgNPs) showed the highest antimicrobial activity, with MIC values of 18.8 mg/L against Staphylococcus aureus and Pseudomonas aeruginosa, and 4.7 mg/L against Candida albicans, along with strong bactericidal effects. HET-CAM assays indicated negligible irritation at concentrations up to 75 mg/L. Cytocompatibility results revealed a dose-dependent response, with fibroblasts being more sensitive. Electrospun nanofibers loaded with dc-AgNPs achieved a 2.6 log reduction against Streptococcus mutans and moderate reductions (0.4–0.7 log) against other pathogens. Conclusions: Ligand engineering critically influences the antimicrobial efficacy and biocompatibility of AgNPs. The incorporation of dc-AgNPs into electrospun nanofibers represents a promising approach for treating biofilm-associated wound infections. Full article

Bone grafting remains limited, and the strategies to design even more structurally complex scaffolds—able to reproduce the hierarchical architecture of bone extracellular matrix—are rapidly growing. In this study, we report the fabrication of a hierarchically structured scaffold produced by layering poly(ε-caprolactone)/gelatin (PCL/Gt) or poly(lactic acid)/gelatin (PLA/Gt) electrospun nanofibers via coaxial electrospinning onto 3D-printed poly(lactic acid) (PLA) scaffolds via fused deposition modeling (FDM). After the printing process, PLA disks (10 × 1 mm, 20% infill, ~80% porosity, pore size ~1.57 mm) were coated with core/shell (PCL/Gt, PLA/Gt) fibers to investigate the in vitro interfacial response of osteoblasts in comparison with monocomponent fibrous coatings (PCL, PLA, Gt). SEM and TEM confirmed that core/shell fibers exhibited bead-free morphologies, with a significant reduction in fiber diameter (≈287–316 nm) and higher interfibrillar porosity compared to monocomponent fibers. FTIR and thermogravimetric analyses indicated the presence of hydrogen bonding between the polyester and gelatin, and the absence of residual solvent after deposition. At the same time, water contact angle measurements confirmed an increase in hydrophilic properties from 80–86° to 120° ascribable to the presence of gelatin. Accordingly, in vitro response of human fetal osteoblasts (hFOB 1.19) exhibited an evident improvement in the case of Gt-based fibrous coatings (i.e., PCL/Gt and PLA/Gt) in terms of early adhesion (4–24 h) and metabolic activity from 3 to 21 days, cell spreading into star-shaped morphologies, formation of extracellular matrix, and mineral phase deposition. In more detail, a remarkable increase in alkaline phosphatase activity was observed in Gt-based coaxial coatings from day 7 onward, with the highest values recorded for PLA/Gt. Overall, we demonstrated that the Gt-based coaxial fibrous coating provided a mix of topological and biochemical cues that synergistically promoted key osteoblast activities at the interface, supporting the regeneration of new bone tissue in highly tailored 3D-printed scaffolds, thus suggesting a promising strategy for personalized regenerative medicine. Full article

Artificial nerve guidance conduits (NGCs) have gained significant attention in the field of peripheral nerve regeneration for the treatment of critically sized nerve defects. Nanotechnology-based NGCs are being explored as potential solutions for repairing and reconstructing peripheral nerve injuries due to their unique structure and topography. In this study, we present a novel core–sheath GelMA/PCL nanofiber construct fabricated through electrospinning and phase separation methods. The core–sheath GelMA/PCL nanofibers replicate the topological morphology of the native extracellular matrix (ECM). The outer layer, composed of GelMA, serves as an “adhesion domain” facilitating direct interaction with surrounding cells and tissues while improving wettability, integrin-mediated cell adhesion/attachment, and degradation. PCL, acting as the “elastic domain” within the nanofibers, enhances mechanical properties, maintains long-term stability of the NGCs, and enables controlled release of GelMA. Histomorphometric analysis along with electrophysiological and behavioral assessments demonstrate that these core–sheath GelMA/PCL nanofiber-based NGCs can activate endogenous mechanisms for peripheral nerve repair while promoting sensory/motor nerve regeneration and functional recovery. Overall, our findings demonstrate that GelMA/PCL nanofibers within the nuclear sheath can effectively remodel the nerve regeneration microenvironment by integrating “mechanical- biochemical” signals, thereby offering a novel strategy for addressing critical-size nerve defects. Full article

Background/Objectives: Guided bone regeneration (GBR) in dental applications requires scaffolds that possess balanced mechanical strength, controlled biodegradability, and excellent biological performance; therefore, this study aims to develop and evaluate a multilayered biofunctional dental membrane designed to enhance mechanical, biological, and antibacterial performance. Methods: The multilayered membrane was fabricated using sequential electrospinning and electrospraying techniques to form a polycaprolactone (PCL)/Collagen first layer and a polyvinyl alcohol (PVA)/Collagen/Hydroxyapatite (HAp) second layer, topped with a final electrospray coating of PVA/Amoxicillin. Characterization was performed via SEM, FTIR, and EDS, followed by evaluations of tensile properties, swelling behavior, hydrolytic degradation, in vitro drug release, disk diffusion antibacterial activity against Staphylococcus aureus and Escherichia coli, and 7-day L929 fibroblast cytocompatibility (ANOVA/Tukey, p < 0.05). Results: SEM, FTIR, and EDS analyses confirmed uniform nanofiber morphology, homogeneous HAp distribution, and successful integration of bioactive compounds. The membrane exhibited a maximum tensile strength of 15.17 N, strain of 25.24%, and stress of 2.16 MPa, while swelling reached ~100% within 2 h and degradation stabilized around 4% weight loss after 48 h. Drug release profiles showed a rapid amoxicillin release in the first 50 min, plateauing at approximately 4.5 mg/L by 350 min, with distinct antibacterial inhibition zones, and the PCL/Col–PVA/Col/HAp–PVA/Amox group demonstrated the highest cell viability (~140%) after 7 days, significantly exceeding the control groups (p < 0.01). Conclusions: These quantitative findings validate the fabricated multilayered membrane’s potential as a mechanically robust, biodegradable, antibacterial, and bioactive scaffold for advanced guided bone regeneration in dental applications. Full article

Mineral powder–based bone grafts exhibit excellent osteoconductivity; however, their clinical efficacy is often compromised by insufficient early-stage tissue ingrowth, leading to particle aggregation and pocket formation within the defect site during the initial healing phase. Here, we report a cotton-type nanofiber-guided mineral graft designed to overcome this early integration failure by creating fibrous pathways for tissue ingress. Cotton-type polycaprolactone (PCL) nanofibers were fabricated via electrospinning using a pin-based collector engineered to induce strong inter-fiber repulsion, resulting in a highly expanded, three-dimensional cottony architecture. Tetracalcium phosphate (TTCP) and α-tricalcium phosphate (α-TCP) mineral particles were subsequently deposited onto the surface of the cottony nanofibers, forming a fibrous–mineral hybrid graft (c-NF@T/α-TCP) in which the nanofibers act as a transient, functionally defined tissue-guiding framework during the early healing phase. The cottony nanofiber network effectively prevented mineral particle aggregation and generated continuous pathways within the graft, facilitating early tissue infiltration and vascular ingress during the first week after implantation. In vivo evaluation in a bone defect model demonstrated that c-NF@T/α-TCP significantly reduced tissue pocket formation at early time points and promoted subsequent bone regeneration compared to mineral powder-only grafts. This study highlights the critical importance of early-stage structural guidance in mineral-based bone grafts and introduces cotton-type nanofiber–guided pathway engineering as a simple yet effective strategy to unlock the regenerative potential of conventional inorganic bone substitutes. 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

Spinal cord injury (SCI) remains a major clinical challenge due to the limited regenerative capacity of the central nervous system (CNS). Effective scaffolds for repair must combine mechanical compatibility with host tissue, controlled degradation matching the time course of regeneration, and microarchitectural features that promote neuronal survival. Electrospun nanofibrous scaffolds mimic the structural and mechanical features of the extracellular matrix, providing critical cues for neuronal adhesion and glial modulation in neural regeneration. Here, we fabricated biodegradable poly(lactic acid)/poly(ε-caprolactone) (PLA/PCL) scaffolds using a dichloromethane/tetrahydrofuran (DCM/THF) solvent system to induce surface porosity via solvent-driven phase separation. The DCM/THF solvent system formulation produced nanofibers with porous surfaces and increased area for cell interaction. PLA/PCL scaffolds showed a Young’s modulus of ~26 MPa and sustained degradation, particularly under oxidative conditions simulating the post-injury microenvironment. In vitro, these scaffolds enhanced neuronal density up to fivefold and maintained ~80% viability over 10 days in primary neuron–glia cultures. Morphometric analysis revealed that DCM/THF-based scaffolds supported astrocytes with preserved process complexity and reduced circularity, indicative of a less reactive morphology. In contrast, scaffolds fabricated with 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) displayed reduced bioactivity and promoted morphological features associated with astrocyte reactivity, including cell rounding and process retraction. These findings demonstrate that solvent-driven control of scaffold microarchitecture is a powerful strategy to enhance neuronal integration and modulate glial morphology, positioning DCM/THF-processed PLA/PCL scaffolds as a promising platform for CNS tissue engineering. Full article

Tendon injuries, whether resulting from trauma, repetitive strain, or degenerative conditions, present a considerable clinical challenge. The natural healing process, which involves inflammatory, proliferative, and remodeling phases, is often inefficient and leads to excessive scar tissue formation, ultimately compromising the mechanical properties of the tendon compared to its native state. This highlights the critical need for innovative approaches to enhance tendon repair and regeneration. Leveraging the regenerative properties of human amniotic membrane (HAM) and electrospun PCL/gelatin nanofibers, this study aims to develop and assess a novel composite scaffold in a rodent model to facilitate improved tendon healing. This prospective experimental study involved 12 male Sprague Dawley rats (250–300 g), randomly assigned to three groups: Group A (No Treatment/No HAM), Group B (HAM-treated), and Group C (HAM with electrospun nanofibers, HAM-NF). A surgically induced tendon injury was created in the left hind limb, while the right limb served as a control. Following surgery, HAM and HAM-NF (0.5 cm²) were applied to the respective treatment groups, and tendon healing was assessed after six weeks. Gait analysis, including stride length and toe-out angle, was conducted both pre-operatively and six weeks post-operatively. Macroscopic and microscopic evaluations were performed on harvested tendons to assess regeneration, comparing treated groups to the controls. Gait analysis demonstrated that the HAM-NF group showed a significant increase in stride length from 11.70 ± 1.50 cm to 12.79 ± 1.71 cm (p < 0.05), with only a modest change in toe-out angle (14.58 ± 2.96° to 16.27 ± 2.20°). In contrast, the No Treatment group exhibited reduced stride length (10.27 ± 2.17 cm to 8.40 ± 1.67 cm) and a marked increase in toe-out angle (16.33 ± 4.51° to 26.47 ± 5.81°, p < 0.05), while the HAM-only group showed mild changes in both parameters. Macroscopic evaluation showed a significant difference in tendon healing. HAM-NF group had the highest score that indicates more rapid tissue regeneration. Histological analysis after 6 weeks showed that tendons treated with HAM-NF achieved a mean histological score of 5.54 ± 4.14, closely resembling the uninjured tendon (6.67 ± 1.63), indicating substantial regenerative potential. The combination of human amniotic membrane (HAM) and electrospun nanofibers presents significant potential as an effective strategy for tendon regeneration. The HAM/NF group exhibited consistent improvements in gait parameters and histological outcomes, closely mirroring those of uninjured tendons. These preliminary results indicate that this biomaterial-based approach can enhance both functional recovery and structural integrity, providing a promising pathway for advanced tendon repair therapies. Full article

Leishmaniasis, a widespread, neglected infectious disease with limited effective treatments and increasing drug resistance, demands innovative therapeutic approaches. In this study, we report the fabrication of pentamidine (PTM)-loaded polycaprolactone (PCL) nanofibers using solution blow spinning (SBS) as a potential topical delivery system for cutaneous leishmaniasis (CL). Homogeneous PCL fiber mats were produced using a simple SBS set-up with a commercial airbrush after optimizing several working parameters. Drug release studies demonstrated sustained PTM release profile over time, which was mechanistically modeled by utilizing the complete nanofiber diameter distribution, obtained from SEM analysis of the blow-spun material. FTIR and XRD analyses were performed to investigate the drug–polymer interactions, revealing molecularly dispersed PTM at low-proportion drug/polymers and partial crystallinity at high loadings. The released PTM exhibited significant leishmanicidal activity against Leishmania major promastigotes. Biological investigations showed that SBS-formulated PTM treatment was consistent with the downregulation of parasite genes involved in cell division and DNA replication (cycA, cyc6, pcna, top2, mcm4) and upregulation of the drug response gene (prp1). The controlled delivery of PTM within SBS-fabricated PCL nanofibers provides an effective therapeutic approach to tackle CL and, through the incorporation of additional drugs, could be extended to address a broader range of cutaneous infections. Full article

The development of sustainable catalysts is the main objective in green chemistry approaches. In this study, a catalytically active polymer based on a tertiary amine was synthesized, functionalized with a photo-crosslinker, and structured into nanofibers via electrospinning technique with polycaprolactone (PCL) as a stabilizing additive. Subsequent photo-crosslinking yielded hierarchically porous polymers with high swelling properties and increased surface areas, thereby improving the accessibility of the immobilized catalytically active sites. The nanofiber mats were incorporated into a microfluidic reactor (MFR) setup and utilized as heterogeneous catalysts for the Knoevenagel reaction of malononitrile with different aldehydes. It was observed that the system demonstrated a substantial improvement in NMR yields (40–60%) and turnover frequencies (50–80 h⁻¹) in comparison to catalytical systems that had been previously published. Reusability studies showed reproducibility of NMR yields over up to three cycles. The obtained results demonstrate the potential of electrospun, photo-crosslinked nanofibers as efficient heterogeneous catalysts in microfluidic synthesis, thus contributing to more sustainable production of valuable malononitrile derivatives. Full article

Chronic and complex wounds require biomaterials that are both cytocompatible and antimicrobial. Herein, electrospun polycaprolactone (PCL) nanofiber membranes were coated with Type I collagen and functionalized with silver nanoparticles (AgNPs). The main objective was to assess fibroblast adhesion, proliferation, and cytotoxicity. Membrane morphology and surface characteristics were analyzed in a previous work by SEM, AFM, and wettability measurements, confirming the transformation from hydrophobic PCL to fully wettable collagen-coated surfaces. In this study, Murine 3T3 fibroblasts were cultured on PCL, PCL–Collagen, PCL–Collagen–Citrate, and PCL–Collagen–AgNPs membranes. Cellular activity was quantified using Alamar Blue assays at 24, 48, and 72 h, while cytotoxicity was determined by LDH release. Cellular viability and adhesion were studied using confocal microscopy. All membrane types supported fibroblast growth, with collagen-coated samples exhibiting the highest metabolic activity. AgNPs-functionalized membranes sustained overall cell viability above 90%, with cytotoxicity values of approximately 10% at 24 h and 20% at 48 h. Antimicrobial evaluations demonstrated complete inhibition of Pseudomonas aeruginosa and vancomycin-resistant Enterococcus, and partial inhibition of Staphylococcus aureus. These results indicate that collagen-coated, AgNPs-functionalized electrospun PCL membranes exhibit both high cytocompatibility and significant antimicrobial activity, supporting their potential as advanced wound-dressing materials. Full article