Core-shell Nanofibers Research Articles

Inhibiting Friction-Induced Exogenous Adhesion via Robust Lubricative Core-Shell Nanofibers for High-Quality Tendon Repair.

Friction is the trigger cause for excessive exogenous adhesion, leading to the poor self-repair of the tendon. To address this problem, we developed electrospun dual-functional nanofibers with surface robust superlubricated performance and bioactive agent delivery to regulate healing balance by reducing exogenous adhesion and promoting endogenous healing. Coaxial electrospinning and our previous developed in situ robust nanocoating growth techniques were employed to create the lubricative/repairable core-shell structured nanofibrous membrane (L/R-NM). The L/R-NM shell featured a robust coating of the zwitterionic PMPC polymer for strong hydration lubrication to resist exogenous healing. The core could achieve sustained platelet-rich plasma release to promote endogenous healing. Friction tests and cell experiments confirmed L/R-NM's prominent lubricating properties and antiadhesive performance in vitro. Rat tendon injury model evaluation indicated that L/R-NM effectively promotes high-quality tendon repair by inhibiting friction-induced exogenous adhesion and promoting endogenous healing. Therefore, we believe that L/R-NM will open a unique novel horizon for tendon repair.

Synergistic enhancement of self-healing and abrasion/corrosion resistance properties of marine anticorrosion coatings with SiO2 modified PA6 core shell nanofibers

Synergistic enhancement of self-healing and abrasion/corrosion resistance properties of marine anticorrosion coatings with SiO2 modified PA6 core shell nanofibers

Citronella oil-loaded electro-spun single and core-shell nano fibers as sustained repellent systems against Aedes aegypti

Citronella oil-loaded electro-spun single and core-shell nano fibers as sustained repellent systems against Aedes aegypti

Shell thickness and defect engineering for eximious thermal, electromagnetic, hydrophobic, and mechanical capabilities in Cu@ammonium gluconate core–shell nanofibers

Shell thickness and defect engineering for eximious thermal, electromagnetic, hydrophobic, and mechanical capabilities in Cu@ammonium gluconate core–shell nanofibers

Wearing comfortable and high electrical output TENGs woven with PTFE core–shell nanofiber yarns

Wearing comfortable and high electrical output TENGs woven with PTFE core–shell nanofiber yarns

Coating V2O5@NaV6O15 Nanofibers with PPy Toward Prominent Sensitivity, Thermal Dissipation, Electromagnetic Protection, Waterproofing, and Mechanical Properties

AbstractExcellent mechanical flexibility, thermal conductivity, and microwave absorption are essential properties for multifunctional materials applied in next‐generation wearable electronics. However, it remains a great challenge to improve the incompatibility among these properties. Herein, high‐quantity V2O5@NaV6O15@PPy core‐shell nanofibers (CSNFs) are synthesized via a simple dissolution‐recrystallization and in situ redox polymerization process. Owing to regular, periodic, and stable sensing signals, their membrane can serve as a strain sensor to accurately detect word pronunciation and body movement. Their TPU films possess high strength, excellent hydrophobicity, and large thermal conductivity (3.56 W m−1 K−1); 7 wt.% load. Besides, the CSNFs exhibit efficient wide‐band microwave absorption (8.56 GHz) and RCS reduction (24.41 dBm2) at a low load (7 wt.%), outperforming most other absorbers. The boosted performance can be ascribed to their 1D structure with multiple heterostructures and abundant defects, which generate conductive loss, diverse polarizations, multiple microwave scattering, and the cooperative heat transfer of electrons and phonons. Further analyses reveal their heat transfer and dielectric loss mechanisms based on the density of states, electric field distribution, and the phonon density of states. Overall, the V2O5@NaV6O15@PPy CSNFs are promising as multifunctional materials for applications in wearable strain sensing, thermal management, EM protection, and Radar stealth, particularly in extreme environments.

Microfluidic Electrospinning Core-Shell Nanofibers for Anti-Corrosion Coatings With Efficient Self-Healing Properties.

Self-healing materials have been extensively explored in metal anti-corrosion fields. However, improving the self-healing efficiency remains a significant work that severely limits their further development. Here, a strategy to fabricate anti-corrosion coatings with efficient self-healing properties based on microfluidic electrospinning technologies and UV-curable healing agents is reported. The damaged composite coating contains core-shell nanofibers that can be completely healed within only 30min, indicating an outstanding healing efficiency. The corrosion current density (Icorr) of the composite coatings containing core-shell nanofibers (abbreviated as composite coatings) is lower than the coatings without any fibers (abbreviated as pure resin coatings) during the test of repeated damage and healing cycles, showing superior resistance to corrosion and repeated self-healing property. The composite coating has even better mechanical properties such as tensile strength, bending strength, and impact strength than the pure resin coating, which are explained by simulating the deformation process. These excellent properties greatly improve the practicability of self-healing coatings in the application of anti-corrosion, especially in some special fields.

Stable Fabrication of Chitosan/Polycaprolactone (CS/PCL) Core-Shell Nanofibers by Electrospinning

Chitosan (CS), with its non-toxic and antibacterial properties, and Poly(ε-caprolactone) (PCL), known for its biodegradability and biocompatibility, are crucial materials in medical applications. This study proposed a solution utilizing electrospinning to manufacture fibers with nanometer-sized core-shell structures from these materials, with CS serving as the fiber core and PCL forming the shell. The influence of manufacturing technology parameters on fiber size and morphology was thoroughly researched and investigated. The solvent system used, Chloroform/Dimethylformamide (DMF), ensured complete solubility, viscosity control, conductivity, and proper solvent evaporation. Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) results clearly demonstrated the morphology and internal structure of the nanofibers. The water contact angle (WCA) measurements of the fiber membrane showed almost no significant change over time, indicating strong hydrophobicity of the nanofibers. Additionally, the FTIR spectrum revealed distinct core-shell layers without any blending between them, while DSC analysis showed the thermal properties of fiber membranes. In summary, the electrospinning of nanofibers proved to be stable, producing thin fibers with an average diameter of approximately 400 nm. These findings are expected to significantly enhance the applicability of CS/PCL nanofibers across various fields, including healthcare and smart agriculture.

Fabrication of novel Cu-embedded core-shell carbon nanofibers with high electrical conductivity via coaxial electrospinning

Electrospun carbon nanofibers (CNFs) have gained an enormous importance due to their unique properties. However, the limitation of electrical conductivity has restricted their applications. In this paper, copper-embedded core-shell CNFs were prepared via coaxial electrospinning process followed by heat treatment. The effect of press on surface structural and electrical properties of electrospun nanofiber mats was elaborately studied by using various loads. The morphology and structures of pressed CNFs were investigated by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The four-point probe technique was used to measure the surface electrical conductivity of CNFs. Based on results, the applied press on nanofibers slightly deforms the graphite-like framework and increases the defective structure of CNFs. The increase of these defects is accompanied by an enhancement of quaternary nitrogen (QN) amount in CNFs, indicating that QN might exist in the graphite-like lattice. These effects become more pronounced with increasing press on nanofibers. The electrical conductivity of CNFs significantly increases while the applied load gradually grows, reaching about 100.7 Scm-1 at 5 tons. The quaternary nitrogen in the graphite layer generates an extra electron for the delocalized π-system, causing an increase in the vibration of π-system, thus improving the electrical conductivity.

Gold/platinum nanorods/temozolomide-UiO-66-NH2 metal-organic frameworks incorporated to chitosan-grafted polycaprolactone/polycaprolactone core-shell nanofibers for glioblastoma treatment during chemo-photothermal therapy

The use of biocompatible metal-organic frameworks (MOFs) and electrospun nanofibrous implants shows promise in preventing the recurrence of postsurgical glioblastoma. In this study, temozolomide (TMZ) and platinum‑gold nanorods (PtAu NRs) were encapsulated into the UiO-66-NH2 MOFs. These were then incorporated into the chitosan-grafted polycaprolactone (PCL) (core)/PCL (shell) nanofibers coated with PtAu NRs for extended release of TMZ during chemo-photothermal therapy against glioblastoma cells. The drug encapsulation efficiency, TMZ release, and in vitro cell viability were investigated for the MOFs, simple nanofibers, core-shell nanofibers, and MOFs-nanofibers. The extended release of TMZ occurred over 44 and 36 days from the core-shell nanofibers coated with PtAu NRs under NIR irradiation at pH values of 7.4 and 5, respectively. The maximum killing of U87 glioblastoma cells was 80.2 % using TMZ-Pt-Au-MOF-core-shell nanofibers coated with PtAu under NIR irradiation. The relative tumor size for the mice bearing glioblastoma and treated with pure core-shell nanofibers, TMZ-Pt-Au-MOF, and TMZ-Pt-Au-MOF-core-shell nanofibers coated with PtAu without NIR irradiation and with NIR irradiation was 4.12, 2.12, 1.65, 0.86, and 0.48, respectively, after 30 days. The synthesized MOF-core-shell nanofibers-Pt-Au NRs implantable device shows potential as a new approach for postsurgical glioblastoma treatment during chemo-photothermal therapy.

Engineered Core-Shell SiC@SiO2 Nanofibers for Enhanced Electromagnetic Wave Absorption Performance.

To enable SiC material to achieve high electromagnetic wave (EMW) absorption performance, solving its impedance mismatch with EMW is necessary. Therefore, a novel approach is proposed for the precise control of impedance matching by adjusting the shell thickness of SiO2 nanolayers on the surface of SiC nanofibers (NFs). High-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) reveals the atomic scale oxidation process of SiC, providing fresh insights into the oxidation mechanism. By oxidizing to construct a heterogeneous core-shell structure nanofiber (NF) can effectively lock the incident EMW inside the NF through the generated charges gathered at the interface, forming an electronic barrier that prevents the outward propagation of EMWs. The produced SiC@SiO2 NFs-3 exhibits exceptional EMW absorption properties, including an impressive minimum reflection loss (RLmin) of -53.09dB and a broad maximum effective absorption bandwidth (EABmax) of 8.85GHz. These findings not only deepen understanding of the oxidation mechanism of SiC but also offer valuable insights for further enhancing the EMW absorption capabilities of SiC materials, paving the way for their application in advanced EMW technologies.

Advances in Electrospun Poly(ε-caprolactone)-Based Nanofibrous Scaffolds for Tissue Engineering.

Tissue engineering has great potential for the restoration of damaged tissue due to injury or disease. During tissue development, scaffolds provide structural support for cell growth. To grow healthy tissue, the principal components of such scaffolds must be biocompatible and nontoxic. Poly(ε-caprolactone) (PCL) is a biopolymer that has been used as a key component of composite scaffolds for tissue engineering applications due to its mechanical strength and biodegradability. However, PCL alone can have low cell adherence and wettability. Blends of biomaterials can be incorporated to achieve synergistic scaffold properties for tissue engineering. Electrospun PCL-based scaffolds consist of single or blended-composition nanofibers and nanofibers with multi-layered internal architectures (i.e., core-shell nanofibers or multi-layered nanofibers). Nanofiber diameter, composition, and mechanical properties, biocompatibility, and drug-loading capacity are among the tunable properties of electrospun PCL-based scaffolds. Scaffold properties including wettability, mechanical strength, and biocompatibility have been further enhanced with scaffold layering, surface modification, and coating techniques. In this article, we review nanofibrous electrospun PCL-based scaffold fabrication and the applications of PCL-based scaffolds in tissue engineering as reported in the recent literature.

Regulation of Osteogenic Differentiation of hBMSCs by the Overlay Angles of Bone Lamellae-like Matrices.

Oriented fibers in bone lamellae are recognized for their contribution to the anisotropic mechanical performance of the cortical bone. While increasing evidence highlights that such oriented fibers also exhibit osteogenic induction to preosteoblasts, little is known about the effect of the overlay angle between lamellae on the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). In this study, bone lamellae-like fibrous matrices composed of aligned core-shell [core: polycaprolactone (PCL)/type I collagen (Col I) + shell: Col I] nanofibers were seeded with human BMSCs (hBMSCs) and then laid over on each other layer-by-layer (L-b-L) at selected angles (0 or 45°) to form three-dimensional (3D) constructs. Upon culture for 7 and 14 days, osteogenic differentiation of hBMSCs and mineralization within the lamellae assembly (LA) were characterized by real-time PCR, Western blot, immunofluorescent staining for osteogenic markers, and alizarin red staining for calcium deposition. Compared to those of random nanofibers (LA-RF) or aligned fibers with the overlay angle of 45° (LA-AF-45), the LA of aligned fibers at a 0° overlay angle (LA-AF-0) exhibited a noticeably higher osteogenic differentiation of hBMSCs, i.e., elevated gene expression of OPN, OCN, and RUNX2 and protein levels of ALP and RUNX2, while promoting mineral deposition as indicated by alizarin red staining and mechanical testing. Further analyses of hBMSCs within LA-AF-0 revealed an increase in both total and phosphorylated integrin β1, which subsequently increased total focal adhesion kinase (FAK), phosphorylated FAK (p-FAK), and phosphorylated extracellular signal kinase ERK1/2 (p-ERK1/2). Inhibition of integrin β1 and ERK1/2 activity effectively reduced the LA-AF-0-induced upregulation of p-FAK and osteogenic markers (OPN, OCN, and RUNX2), confirming the involvement of integrin β1-FAK-ERK1/2 signaling. Altogether, the overlay angle of aligned core-shell nanofiber membranes regulates the osteogenic differentiation of hBMSCs via integrin β1-FAK-ERK1/2 signaling, unveiling the effects of anisotropic fibers on bone tissue formation.

Electrospun gelatin/tea polyphenol@pullulan nanofibers for fast-dissolving antibacterial and antioxidant applications.

Bio-based active food packaging materials have a high market demand. We use coaxial electrospinning technology to prepare core-shell structured nanofibers with sustained antibacterial and antioxidant properties. The fiber core layer was composed of gelatin and tea polyphenols, whereas tea polyphenols provide antibacterial and antioxidant properties; the fiber sheath was composed of pullulan polysaccharides with antioxidant properties. By using a scanning electron microscope, it can be seen that the diameter distribution of the prepared nanofibers was uniform and the surface is smooth; using a transmission electron microscope, it can be clearly seen that the nanofibers have a core-shell structure; Fourier Transform Infrared and X-ray diffraction analysis indicate that the nanofibers have an amorphous structure; the 2,2-diphenyl-1-picrylhydrazyl free radical scavenging shows that nanofibers have higher antioxidant properties with the addition of tea polyphenols; antibacterial test showed that nanofibers had obvious inhibitory effect on the growth of Staphylococcus aureus and Escherichia coli; and the nanofiber film dissolution test shows that nanofibers can be used as fast soluble active packaging. Finally, core-sheath-structured nanofibers can serve as active packaging for instant food, possessing both rapid water solubility and excellent antibacterial and antioxidant activity, making water-soluble nanofibers interesting applications in the field of food packaging.

A Robust Core-Shell Nanofabric with Personal Protection, Health Monitoring and Physical Comfort for Smart Sportswear.

Smart textiles with a high level of personal protection, health monitoring, physical comfort, and wearing durability are highly demanded in clothing for harsh application scenarios, such as modern sportswear. However, seamlessly integrating such a smart clothing system has been a long-sought but challenging goal. Herein, based on coaxial electrospinning techniques, a smart non-woven textile (Smart-NT) integrated with high impact resistance is developed, multisensory functions, and radiative cooling effects. This Smart-NT is comprised of core-shell nanofibers with an ionic conductive polymer sheath and an impact-stiffening polymer core. The soft smart textile, with a thickness of only 800µm, can attenuate over 60% of impact force, sense pressure stimulus with sensitivity up to 201.5 kPa-1, achieve temperature sensing resolution of 0.1°C, and reduce skin temperature by ≈17°C under a solar intensity of 1kWm-2. In addition, the stretchable Smart-NT is highly durable and robust, retaining its multifunction features over 10000 bending and multiple washing cycles. Finally, application scenarios are demonstrated for real-time health monitoring, body protection, and physical comfort of smart sportswear based on Smart-NT for outdoor sports. The strategy opens a new avenue for seamless integration of smart clothing systems.

Fabrication and characterization of electrospun core-shell nanofibers of bilayer zein/pullulan emulsions crosslinked by genipin

In this study, the electrospun core-shell nanofibers of zein/pullulan stabilized bilayer emulsions before and after genipin crosslinking were fabricated. The experimental results indicated that the addition of pullulan increased the apparent viscosity and elastic modulus of the bilayer emulsions, which was further increased after the chemical crosslinking of genipin. The nanofiber diameter increased from 102.9 nm to 169.9 nm with the increasing ratio of pullulan, but increased significantly to a range of 405.6–708.0 nm after genipin crosslinking. The electrospun nanofiber films of crosslinked emulsions had higher thermal stability and stronger water stability. The FTIR result proved the existence of hydrogen bond interaction between the zein, pullulan, and genipin molecules. In addition, before and after crosslinking, the encapsulation efficiency of electrospun fiber films for camellia oil was >77.68 %, and the maximum encapsulation efficiency could reach 87.94 %, and there was no significant change during the 7-day storage period, showing good stability. These research results can provide a theoretical basis for the encapsulation of hydrophobic active substances in zein-based emulsion electrospun core-shell nanofibers.

Core-Shell Composite Nanofibers with High Temperature Resistance, Hydrophobicity and Breathability for Efficient Daytime Passive Radiative Cooling.

Radiative cooling technology, which is renowned for its ability to dissipate heat without energy consumption, has garnered immense interest. However, achieving high performance, multifunctionality, and smart integration while addressing challenges such as film thickness and enhancing anisotropic light reflection remains challenging. In this study, a core-shell composite nanofiber, PVDF@PEI, is introduced and designed primarily from a symmetry-breaking perspective to develop highly efficient radiative cooling materials. Using a combination of solvent-induced phase separation (EIPS) inverse spinning and (aggregation) self-assembly methods (EISA or EIAA) and coaxial electrostatic spinning (ES), superconformal surface anisotropic porous nanofiber membranes are fabricated. These membranes exhibit exceptional thermal stability (up to 210°C), high hydrophobicity (contact angle of 126°), robust UV protection (exceeding 99%), a fluorescence multiplication effect (with a 0.6% increase in fluorescence quantum efficiency), and good breathability. These properties enable the material to excel in a wide range of application scenarios. Moreover, this material achieved a remarkable daytime cooling temperature of 8°C. The development of this fiber membrane offers significant advancements in the field of wearables and the multifunctionality of materials, paving new paths for future research and innovation.

Sodium alginate hydrogels co-encapsulated with cell free fat extract-loaded core-shell nanofibers and menstrual blood stem cells derived exosomes for acceleration of articular cartilage regeneration

This study presents a novel scaffold system comprising sodium alginate hydrogels (SAh) co-encapsulated with cell-free fat extract (CEFFE)-loaded core-shell nanofibers (NFs) and menstrual blood stem cell-derived exosomes (EXOs). The scaffold integrates the regenerative potential of EXOs and CFFFE, offering a multifaceted strategy for promoting articular cartilage repair. Coaxially electrospun core-shell NFs exhibited successful encapsulation of CEFFE and seamless integration into the SAh matrix. Structural modifications induced by the incorporation of CEFFE-NFs enhanced hydrogel porosity, mechanical strength, and degradation kinetics, facilitating cell adhesion, proliferation, and tissue ingrowth. The release kinetics of growth factors from the composite scaffold demonstrated sustained and controlled release profiles, essential for optimal tissue regeneration. In vitro studies revealed high cell viability, enhanced chondrocyte proliferation, and migration in the presence of EXOs/CEFFE-NFs@SAh composite scaffolds. Additionally, in vivo experiments demonstrated significant cartilage regeneration, with the composite scaffold outperforming controls in promoting hyaline cartilage formation and defect bridging. Overall, this study underscores the potential of EXOs and CEFFE-NFs integrated into SAh matrices for enhancing chondrocyte viability, proliferation, migration, and ultimately, articular cartilage regeneration. Future research directions may focus on elucidating underlying mechanisms and conducting long-term in vivo studies to validate clinical applicability and scalability.

Fabrication and characterization of oleic acid/sesame protein isolate/ poly (vinyl) alcohol core-shell nanofibers: Mitigating lipid oxidation by emulsion electrospinning

Formulated oil-in-water (O/W) emulsions of oleic acid (OA) using sesame protein isolate (SPI) were processed via emulsion electrospinning with poly (vinyl) alcohol (PVA) to fabricate core-shell nanofibers for lipid oxidation prevention. The emulsion droplet size and viscosity increased as the oil volume fraction rose from 5 % to 30 %. The morphology tests and Fourier transform infrared spectroscopy (FTIR) confirmed the uniformity of nanofibers and OA encapsulation with hydrogen bonding. The thermal stability, mechanical properties, and water contact angle (WCA) of the nanofiber films improved with increased OA content. Encapsulation efficiency was 94.76 % and storage stability was maintained for 7 days in 5 % oil fraction nanofibers. The nanofibers showed lower oxidation and superior oxidative resistance to free OA, with the lowest peroxide value (POV, 2.14 mmol/L) and thiobarbituric acid-reactive substances (TBARS, 36.75 μmol/L). In conclusion, the OA/SPI/PVA (PE) core-shell nanofibers via emulsion electrospinning are efficient for fatty acid encapsulation in functional foods.

Co-doped MOF-5 and carbon nanotube nanoparticles enhancing stability and high output performance in core-shell nanofibers for piezoelectric nanogenerators

The interfacial interaction of carbon nanotubes (CNTs) significantly enhances the output capability of piezoelectric nanogenerators (PENGs). However, overcoming the limitation of low specific surface area in one-dimensional materials remains a significant challenge. This paper introduces a hydrothermal method for composite MOF (C-M) using CNTs and MOF-5, demonstrating localized co-doping between them. Coaxial electrospun piezoelectric fiber membranes (C-MNF) were then prepared using PVDF/PAN as the matrix. Benefiting from C-M’s excellent crystallinity and its synergistic interaction with the polymer matrix, the C-MNF-based PENG showed a 125 % increase in output voltage, reaching ∼25 V, compared to coaxial membranes simply mixing MOF-5 and CNTs. As a result, its short-circuit current was ∼1.8 μA, with a piezoelectric coefficient d33 of ∼400 pC N−1. Consequently, this material exhibits superior piezoelectric output capabilities, paving the way for future functional material fabrication.