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Nanotechnology-enabled drug delivery has been demonstrated to be a superior cancer treatment. Lung, liver, brain, breast, and cervical cancer cells have all demonstrated extreme cytotoxicity when exposed to electrospun nanofibers encasing anti-cancerous drugs. Herein, we developed Polyurethane (P)/Carboxymethyl chitosan (C)/Polyethylene oxide (P) (termed as PCP) core-shell nanofibers were loaded with gemcitabine (GEM) and folic acid (FA) for regulated GEM and FA release towards the apoptosis of A549 and H1299 cells. Analysis using scanning electron microscopy (SEM) and x-ray diffraction (XRD) were used to characterise the fabricated nanocarriers. Synthesised nanofibers have been studied for their drug-loading and release efficacy of GEM/MOFs and FA/MOFs. The cytotoxicity data suggested that PCP loaded with GEM and FA might be employed to treat a wide range of cancers. The cell morphological investigation was examined by the acridine orange and ethidium bromide staining, and the DAPI staining assessed the nuclear damage of the cells. The flow cytometry methods investigated the hallmark of apoptosis. There is an opportunity for promising GEM delivery for lung cancer treatment with the FA-GEM/UiO-66 loaded-PCP core-shell nanofibers. [ABSTRACT FROM AUTHOR]

Polymeric composites for manipulating the sustained release of an encapsulated active ingredient are highly sought after for many practical applications; particularly, water-insoluble polymers and core–shell structures are frequently explored to manipulate the release behaviors of drug molecules over an extended time period. In this study, electrospun core–shell nanostructures were utilized to develop a brand-new strategy to tailor the spatial distributions of both an insoluble polymer (ethylcellulose, EC) and soluble polymer (polyvinylpyrrolidone, PVP) within the nanofibers, thereby manipulating the extended-release behaviors of the loaded active ingredient, ferulic acid (FA). Scanning electron microscopy and transmission electron microscopy assessments revealed that all the prepared nanofibers had a linear morphology without beads or spindles, and those from the coaxial processes had an obvious core–shell structure. X-ray diffraction and attenuated total reflectance Fourier transform infrared spectroscopic tests confirmed that FA had fine compatibility with EC and PVP, and presented in all the nanofibers in an amorphous state. In vitro dissolution tests indicated that the radical distributions of EC (decreasing from shell to core) and PVP (increasing from shell to core) were able to play their important role in manipulating the release behaviors of FA elaborately. On one hand, the core–shell nanofibers F3 had the advantages of homogeneous composite nanofibers F1 with a higher content of EC prepared from the shell solutions to inhibit the initial burst release and provide a longer time period of sustained release. On the other hand, F3 had the advantages of nanofibers F2 with a higher content of PVP prepared from the core solutions to inhibit the negative tailing-off release. The key element was the water permeation rates, controlled by the ratios of soluble and insoluble polymers. The new strategy based on core–shell structure paves a way for developing a wide variety of polymeric composites with heterogeneous distributions for realizing the desired functional performances. [ABSTRACT FROM AUTHOR]

Polymer dielectrics have been widely employed in pulsed power systems, but their applications are severely restricted by the low energy density. Incorporating core‐shell nanofillers is one promising strategy to enhance the energy density of polymer dielectrics. Nowadays, core‐shell nanofillers are mainly prepared via chemical coating strategies, which always involve complex chemical synthesis procedures. Herein, a unique physical coating strategy is developed to prepare core‐shell TiO2@Au nanofibers consisting of monodispersed Au nanoparticles homogeneously anchored on the TiO2 nanofibers. Interestingly, the TiO2@Au nanofibers show outstanding dielectric energy storage boosting capability. Specifically, with merely introducing 0.1 wt.% TiO2@Au nanofillers, the TiO2@Au/PVDF composite exhibits a substantially enhanced breakdown strength of 749 MV m−1, which reaches 152.8% of PVDF. Meanwhile, a high dielectric constant of 10.2 (114.1% of PVDF) is obtained. Consequently, an ultrahigh energy density of 18.6 J cm−3, which is 250.1% of PVDF, is achieved. It is further revealed that the significant energy storage boosting effect is originated from the Coulomb blockade and micro‐capacitor effects of the TiO2@Au nanofibers. This work establishes a unique paradigm for the facile preparation of core‐shell nanomaterials, which have huge potential for both dielectric energy storage and other functional nanocomposites. [ABSTRACT FROM AUTHOR]

Core–shell nanostructures are powerful platforms for the development of novel nanoscale drug delivery systems with sustained drug release profiles. Coaxial electrospinning is facile and convenient for creating medicated core–shell nanostructures with elaborate designs with which the sustained-release behaviors of drug molecules can be intentionally adjusted. With resveratrol (RES) as a model for a poorly water-soluble drug and cellulose acetate (CA) and PVP as polymeric carriers, a brand-new electrospun core–shell nanostructure was fabricated in this study. The guest RES and the host CA molecules were designed to have a reverse gradient distribution within the core–shell nanostructures. Scanning electron microscope and transmission electron microscope evaluations verified that these nanofibers had linear morphologies, without beads or spindles, and an obvious core–shell double-chamber structure. The X-ray diffraction patterns and Fourier transform infrared spectroscopic results indicated that the involved components were highly compatible and presented in an amorphous molecular distribution state. In vitro dissolution tests verified that the new core–shell structures were able to prevent the initial burst release, extend the continuous-release time period, and reduce the negative tailing-off release effect, thus ensuring a better sustained-release profile than the traditional blended drug-loaded nanofibers. The mechanism underlying the influence of the new core–shell structure with an RES/CA reverse gradient distribution on the behaviors of RES release is proposed. Based on this proof-of-concept demonstration, a series of advanced functional nanomaterials can be similarly developed based on the gradient distributions of functional molecules within electrospun multi-chamber nanostructures. [ABSTRACT FROM AUTHOR]

The resin‐rich region between the fiber laminates of a fiber‐reinforced composite is susceptible to matrix damage impeding the composite's integrity. Hence, this study intends to interlayer core–shell poly(lactic) acid (PLA) nanofibers between the flax fibers as a preventive and reactive mechanism to matrix damages in the resin‐rich area. The nanofibers prevent premature damage by suppressing or mitigating crack propagation and in the event of damage to the nanofibers, it reacts by releasing the encapsulated healing agent. Upon interlayering the flax fiber laminates with self‐healing core–shell nanofibers, the flexural modulus exhibited an increment of 31% whereas the short beam strength improved by 19%. Self‐healing traits of the composites were assessed by subjecting the composites to repeated flexural or short beam strength tests for several load cycles. Upon initial damage to the composites, the composites exhibited a full retention and improvement in mechanical properties. The self‐healing composites were also able to withstand more loading cycles than the conventional composite under repeated short‐beam strength tests. Under both configurations, the damaged self‐healing composites exhibited a residual strength greater than or equivalent to the ultimate strength of a pristine flax fiber composite. Highlights: Fabrication of EP/flax self‐healing composites by PLA core–shell nanofibers.Interlayering healing nanofiber mats between flax fabrics in an FRP composite.Nanofiber interlayers exhibited a profound impact on the composite properties.Nano mats facilitate autonomous repair of internal defects within matrices.The self‐healing composites showed full retention and mechanical strength. [ABSTRACT FROM AUTHOR]

In this study, three kinds of electrohydrodynamic atomization (EHDA) processes (electrospraying, electrospinning, and coaxial electrospinning) are implemented to create hydroxypropyl methylcellulose (HPMC) based ultra‐thin products for providing the fast dissolution of a poorly water‐soluble drug ketoprofen (KET). An EHDA apparatus, characterized by a novel spinneret, is homemade for conducting the three processes. The three types of products are electrospun nanofibers E1, electrosprayed microparticles E2, and core‐shell nanofibers E3. SEM and TEM results indicate that they have the anticipated morphologies and inner structures. X‐ray diffraction and Fourier Transform Infrared results verify that KET is mainly amorphous in all the composites due to its fine compatibility with HPMC. In vitro dissolution tests demonstrate that the drug rapid release performances has an order of E3>E1>E2≫KET powders. The fast dissolution mechanisms are suggested and the advantages of the three products are compared. The super performance of E3 in furnishing the rapid release is attributed to a synergistic action of small size (of the shell thickness), high porosity, amorphous state of drug, and the solubility of HPMC. EHDA nanostructures can support the development of nano drug delivery systems (DDSs) through tailoring the spatial distribution of drug molecules within the nano products. [ABSTRACT FROM AUTHOR]

Shell materials play significant impact on corrosion resistance and mechanical properties on self‐healing coating of composite with core‐shell nanofiber. In this paper, three promising shell materials were investigated to optimize the performance of self‐healing coating. Self‐healing core‐shell nanofibers with different shell materials were prepared with coaxial electrospinning. The resulting nanofibers were used to prepare self‐healing corrosion resistance coating. The tensile test revealed a notable enhancement in the tensile strength of PA6 core‐shell nanofiber epoxy composite coatings compared with the epoxy coating, demonstrating increase of 26.92%. Friction and wear test indicated reductions in the friction coefficients of PAN, PVDF, and PA6 core‐shell nanofibers by 13.82%, 12.44%, and 26.27%, respectively. The self‐healing and anti‐corrosion abilities were evaluated through electrochemical impedance spectroscopy (EIS) test. All three coatings exhibited exceptional self‐healing efficiencies exceeding 90%, highlighting the substantial potential of the chosen shell materials as nanocontainers for self‐healing agent. Results indicate that the nanofibers with PA6 as shell material can achieve the best enhancement performance, which has a greater potential for the corrosion protection and long‐lasting use of offshore wind turbine tower coatings. Highlights: Optimizing coating performance by screening coaxial nanofibers for shell materialsShell material can improve the tensile strength of coating up to 26.92%Friction coefficient of PA6 nanofiber coating was about 15% lower than PAN and PVDFAll three coatings exhibited exceptional self‐healing efficiencies exceeding 90% [ABSTRACT FROM AUTHOR]

In this study, a series of AgCl/ZnO-loaded nanofibrous membranes were prepared using coaxial electrospinning. Their physical and chemical characteristics were evaluated by SEM, TEM, XRD, XPS, IR, PL, and UV–visible spectrometer, and the photocatalytic experiments using methylene blue (MB) as a model pollutant. The formation of AgCl/ZnO heterojunction and the structure of core–shell nanofibers with porous shell layer were confirmed. AgCl/ZnO photocatalysts were also effectively loaded onto the surfaces of the porous core–shell nanofibers. The results of photocatalytic experiments revealed that the AgCl/ZnO (MAgCl:MZnO = 5:5)-loaded nanofibrous membrane achieved a degradation efficiency of 98% in just 70 min and maintained a photocatalytic efficiency exceeding 95% over the first five experimental cycles, which successfully addressed the issues of photocatalytic efficiency loss during the photodegradation of MB with AgCl/ZnO nanoparticles as photocatalyst. The photodegradation mechanism was also researched and proposed. [ABSTRACT FROM AUTHOR]

This work investigates the low‐velocity impact (LVI) and self‐healing behavior of carbon fiber composite laminates interlaced with electrospun polyacrylonitrile core–shell nanofibers (PAN@CFRP). The main goal is to investigate the influence of different stacking configurations of core–shell nanofibers on the impact resistance and self‐healing properties of composite laminates. To achieve the purpose, three different stacking configurations were designed and tested alongside virgin specimens. The damage mechanism and self‐healing of laminates following LVI were determined using ultrasonic C‐scan and cross‐sectional microscopy examinations. At an impact energy of 14.1 J, the flexural strength of the post‐healing PAN‐3@CFRP specimen reached 95.0% of the initial value, whereas at an impact energy of 21.8 J, severe impact damage was observed in the laminates with different configurations. Among the laminates, the PAN‐1@CFRP specimen had the highest flexural strength after healing, which reached 80.1% of its pre‐impact strength. As observed, the impact resistance and self‐healing capacity of composites could be significantly enhanced by optimizing the distribution configuration of core–shell nanofibers for various impact energies. Highlights: The introduction of electrospun core–shell nanofibers has not significantly compromised the mechanical properties of the composites, but rather enhanced their toughness.The addition of core–shell nanofibers significantly enhances the impact resistance of the composites and imparts excellent self‐healing properties to the material.The flexural strength of impact‐damaged specimens with different stacking configurations can be restored up to 95% of the undamaged specimen after repair treatment.Significantly improved impact resistance and self‐healing ability of laminates by optimizing the distribution configuration of core–shell nanofibers between composite layers. [ABSTRACT FROM AUTHOR]

Gas sensors play an important role in environmental detection and exhaled breath biomarker detection. In this paper, Co 3 O 4 /TiO 2 core-shell NFs were synthesized by coaxial electrostatic spinning method. The morphology, structure and composition of the composites were analyzed by SEM, TEM, EDS, XRD and XPS. The results of conventional static gas sensitivity performance tests showed that the Co 3 O 4 /TiO 2 sensors exhibited a P-type response with excellent sensing performance to acetone. The higher response values and better selectivity of Co 3 O 4 /TiO 2 sensors for acetone were observed compared to Co 3 O 4 NFS and TiO 2 NFS sensors, and the shortcomings that cannot be recovered from TiO 2 NFS have also been significantly improved. In addition, the breath simulation experiments showed that the Co 3 O 4 /TiO 2 sensors have a lower acetone detection limit down to 500 ppb. The initial resistance of the Co 3 O 4 /TiO 2 sensor does not change significantly with relative humidity increasing, and the response value fluctuates by 1.5% at 300 °C. The enhanced acetone sensing performance of Co 3 O 4 /TiO 2 is ascribed to the heterojunction and porous structure which result in more adsorbed active sites on the material surface. With the advantages of low detection limit and high anti-humidity, Co 3 O 4 /TiO 2 gas sensors are expected to become a potential candidate for the detection of acetone in exhaled gas of patients with diabetes in clinical non-invasive testing. [ABSTRACT FROM AUTHOR]

Abstract In this study, three kinds of electrohydrodynamic atomization (EHDA) processes (electrospraying, electrospinning, and coaxial electrospinning) are implemented to create hydroxypropyl methylcellulose (HPMC) based ultra‐thin products for providing the fast dissolution of a poorly water‐soluble drug ketoprofen (KET). An EHDA apparatus, characterized by a novel spinneret, is homemade for conducting the three processes. The three types of products are electrospun nanofibers E1, electrosprayed microparticles E2, and core‐shell nanofibers E3. SEM and TEM results indicate that they have the anticipated morphologies and inner structures. X‐ray diffraction and Fourier Transform Infrared results verify that KET is mainly amorphous in all the composites due to its fine compatibility with HPMC. In vitro dissolution tests demonstrate that the drug rapid release performances has an order of E3>E1>E2≫KET powders. The fast dissolution mechanisms are suggested and the advantages of the three products are compared. The super performance of E3 in furnishing the rapid release is attributed to a synergistic action of small size (of the shell thickness), high porosity, amorphous state of drug, and the solubility of HPMC. EHDA nanostructures can support the development of nano drug delivery systems (DDSs) through tailoring the spatial distribution of drug molecules within the nano products.

Clarithromycin as a macrolide antibiotic and zinc oxide (ZnO) nanoparticles with antibacterial and anti-inflammatory properties was incorporated into the chitosan/gelatin/polyurethane (PU) core-shell nanofibers prepared by the coaxial electrospinning method. The morphology and structure of nanofibers were characterized using SEM, FTIR, water contact angle, degradation rate, and swelling tests. The mean fiber diameters of the chitosan/gelatin/PU (CGP), CGP containing 1000 lM clarithromycin, CGP containing 2000 lM clarithromycin, CGP containing 0.5% ZnO, CGP containing 1 wt% ZnO, CGP containing 1000 lM clarithromycin, and 0.5 wt% ZnO and CGP containing 2000 lM clarithromycin, and 1 wt% ZnO were 210 ± 110 nm, 235 ± 100 nm, 250 ± 120 nm, 300 ± 120 nm, 360 ± 130 nm, 410 ± 130 nm, and 460 ± 140 nm, respectively. The gradual faster release of ZnO nanoparticles from core-shell nanofibers was obtained within 24 h; whereas, the sustained release of clarithromycin was achieved during 120 h. Loading of clarithromycin and ZnO nanoparticles into the nanofibers resulted in 100% bactericidal activity of core-shell nanofibers against both Escherichia coli and Staphylococcus aureus. The cell viability results indicated that loading of 0.5 wt% ZnO nanoparticles and 2000 lM clarithromycin was suitable for the development of the synthesized core-shell nanofibers as a potential wound dressing. [ABSTRACT FROM AUTHOR]

Carbon fiber composites containing core–shell nanofibers (PAN@CFRP) were prepared by incorporating electrospun polyacrylonitrile core–shell nanofibers between the layers of carbon fiber reinforced polymer composites and the damage healing ability was assessed after being subjected to low‐velocity impact. Three impact energies (25.2, 33.5, and 41.9 J) were selected for the study. The incorporation of core–shell nanofibers improved the impact resistance of the composites compared with pure carbon fiber composites (CFRP); the PAN@CFRP specimens were found to have a smaller damage area and a lower damage level by visual observation and optical microscopy. The healing efficiency was 66.3%, 43.5%, and 8.83% for the residual compressive strength and was normalized to the residual compressive strength when the impact energy was less than 37.5 J. The healed materials were found to recover more than 80% of their undamaged residual compressive strength when the impact energy was less than 37.5 J. Therefore, the core–shell nanofiber healing system can, to a certain extent, solve the problems caused by the incorporation of other healing systems, and can largely recover the impact damage encountered in practical applications. [ABSTRACT FROM AUTHOR]

Core-shell nanofibers consisted of chitosan/polyvinyl alcohol as shell and TiO2/Ag nanoparticles as core (abbreviated as (TiO2@AgNPs)@(CS/PVA)) are synthesized by electrospinning method for improving the functional properties of the epoxy polymer coatings. The agglomeration of the core-shell network is prevented through fabrication on carbon steel surface. Meanwhile, the presence of unique amine and hydroxyl functional groups on the surface of the CS/PVA nanofibers would provide a crosslinking with the epoxy resin molecules with merits of reducing the gaps between epoxy coating and fillers and enhancing the blocking effect of the fibers. The electrochemical impedance spectroscopy reveals that the resistance of the epoxy coating loaded with the core-shell nanofibers is almost 3 times more than that of the blank sample during 30 days of soaking in the 3.5 wt% NaCl electrolyte. Moreover, the (TiO2@AgNPs)@(CS/PVA)/epoxy coating has shown high antibacterial activity against S. aureus with the highest antibacterial rate of 87% after 24 h storage in the solution of phosphate buffer salt. The developed core-shell nanofibers embedded within epoxy coating with enhanced anticorrosion and antibacterial properties could provide a promising application in various maritime fields for achieving both anticorrosion and antifouling properties in one coating system. [ABSTRACT FROM AUTHOR]

Advanced application of coaxial electrospinning nanofibers in controlled drug release systems has gathered much attention since they have had a tunable structure for tailored release of drugs, including various proteins, growth factors, antibacterial and anticancer agents. The composite polymer poly(l‐lactide‐co‐ε‐caprolactone) (PLCL) blended with gelatin (GE) was used as the shell material to electrospin core–shell nanofibers. Model drug doxorubicin hydrochloride (DOX) was encapsulated in the core layers. The morphology and core–shell structure were evaluated by SEM and TEM respectively. The existence of DOX in the inner part of DOX/PLCL/GE nanofibers could be proved by Fourier transform infrared spectroscopy results. The water contact angle test results indicated that DOX/PLCL/GE nanofibers all possess good hydrophilicity with water contact angles as low as 51.2°. The in vitro release results indicated that the DOX/PLCL/GE nanofibers showed a sustained release profile for 480 h. The fitting results showed that the release kinetics of DOX from nanofibers was consistent with a Ritger–Peppas model, presenting a typical Fickian diffusion mechanism. Overall, the DOX/PLCL/GE core–shell nanofibers showed regulable mechanical properties and could be used as a promising drug release system for drug sustained release and tissue engineering. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In the present study, paclitaxel (PTX), multi‐walled carbon nanotubes (MWCNTs), and doxorubicin (DOX) have been simultaneously doped into the poly(ϵ‐caprolactone) (PCL)/chitosan/zein core‐shell nanofibers to increase its cytotoxicity for MCF‐7 breast cancers killing. The physico‐chemical properties of synthesized nanofibers were determined by scanning electron microscope, Fourier‐transform infrared spectroscopy, tensile strength, and degradation rate determinations. The in vitro release studies demonstrated the sustained release of drugs from core‐shell nanofibrous scaffold. The cytotoxicity and compatibility of core‐shell nanofibers were investigated by their treating with MCF‐7 breast cancer cells and L929 normal cells, respectively. PCL/PTX/chitosan/zein/MWCNTs/DOX core‐shell nanofibers containing 1 wt% MWCNTs, 100 μg ml−1 DOX and 100 μg ml−1 PTX had a high biocompatibility with a 84% MCF‐7 cancer cells killing. The in vivo studies revealed the synergic effects of MWCNTs and anticancer drugs on the tumor inhibition. This method could be considered as a new way for developing of MWCNTs loaded‐nanofibers for cancer treatment in future. [ABSTRACT FROM AUTHOR]

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. [Display omitted] [ABSTRACT FROM AUTHOR]

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. [Display omitted] [ABSTRACT FROM AUTHOR]

Electrospun nanofibrous membranes, with their unique structural features, can potentially enhance wound healing through controlled delivery of active agents. Here, an innovative porous nanofibrous membrane was developed as a dressing patch with antibacterial and anti-inflammatory functionalities for cutaneous wound healing. Zinc oxide nanoparticles (ZnO NPs) and Salvia abrotanoides essential oil (SAEO) were incorporated into sodium alginate, which served as the shell. Poly(ε-caprolactone) was used as the core of coaxial electrospun wound dressing nanofibers (PCL/SA@ZnO/SAEO). With the addition of ZnO NPs and SAEO, the average diameter of nanofibers was 187 ± 51 nm, with improved tensile strength (4.7 ± 0.4 MPa), elongation at break (32.9 ± 2.1), and elastic modulus (21.4 ± 2.0). Concurrent application of ZnO NPs and SAEO increased antimicrobial activity against Staphylococcus aureus and Escherichia coli and promoted the proliferation, attachment, and viability (>90 %) of L929 cells. The PCL/SA@ZnO/SAEO scaffold accelerated the healing time with total wound healing over 14 days in mouse models carrying full-thickness wounds compared to the nanofibrous scaffold without additives. Histopathological examinations demonstrated better tissue regeneration, i.e., enhanced collagen deposition, improved re-epithelialization, and neovascularization, and increased quantity of hair follicles. Moreover, the chicken chorioallantoic membrane assay confirmed the synergistic angiogenic effects of SAEO and ZnO NPs. Finally, the in vitro and in vivo results proposed the bioactive core-shell nanofibers synthesized as encouraging wound dressing materials for hastening the healing of cutaneous wounds. [Display omitted] [ABSTRACT FROM AUTHOR]

A novel composite core‐shell nanofibers of poly(vinyl acetate) (PVAc) as core incorporated with magnesium oxide nanoparticles (MgO NPs) and cellulose acetate (CA) as shell were prepared using co‐axial electrospinning technique. Core‐shell morphology of the prepared composite nanofibers was confirmed by scanning electron microscope (SEM) and field emission‐SEM (FE‐SEM) imaging techniques and presence of metal oxide in core‐shell nanofibers was confirmed from the energy dispersive X‐ray (EDX) analysis. Further, thermal, chemical and mechanical properties of the prepared materials were studied with Fourier transform‐infrared spectroscopy (FTIR), powder X‐ray diffraction (XRD), tensile measurements, thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC) analysis. Finally, fire retardant properties of the prepared nanofibers were studied by inclined flammability and limited oxygen index (LOI) testing. Higher mechanical strength and enhanced fire resistance was reported from the above thorough analysis and therefore, the prepared material could fit well in fire resistance applications. [ABSTRACT FROM AUTHOR]

The biocompatible and biodegradable polymers of poly (glycerol sebacate) (PGS) and poly (1,8-octanediol citrate) (POC) were used to fabricate a core–shell structure, in this research. The polymers were synthesized by polycondensation, and then electrospun with the second polymer of polycaprolactone (PCL). The morphology, mechanical, and physical properties of the PGS/PCL, POC/PCL, and the core–shell structure (PGS/PCL–POC/PCL) were obtained. The in vitro degradation and the response of the retinal cells on the scaffolds were also investigated. The presence of the POC in the composition increased the fiber diameter from 409 nm in the PGS/PCL scaffold to 474, and 521 nm in the POC/PCL, and the core–shell scaffolds, respectively. A similar trend was observed in the surface pore size of the scaffolds. The porosity of the scaffolds was measured in the range of 40–60%. The transmission electron microscopy confirmed the core–shell structure of the scaffold. The chemical structure of the scaffolds was also investigated using FTIR. According to the mechanical experiments, the PGS/PCL and PGS/PCL–POC/PCL showed relatively close tensile modulus, ultimate tensile strength, and strain at break to the retina properties. The POC contained scaffolds illustrated higher hydrophilicity and degradation rate compared to the PGS/PCL scaffold. The MTS experiments demonstrated no cytotoxicity in the prepared scaffolds. The cultured cells were attached and proliferated very well on all the scaffolds, especially on the POC contained one. According to the obtained results, the PGS/PCL–POC/PCL coaxial structure was a suitable scaffold for retinal tissue engineering application. [ABSTRACT FROM AUTHOR]

Coaxial electrospinning is a robust technique to prepare core-shell nanofibers for various biomedical applications such as tissue engineering. In this study, the coaxial electrospinning method was used to prepare two different core-shell nanofibers based on polycaprolactone/polyvinyl alcohol (PCL/PVA) and polycaprolactone/collagen (PCL/Col). The mechanical (e.g., shear viscosity and surface tension) and chemical properties of the nanofibers were characterized and compared. The results showed that PCL/Col nanofibers have higher stability and better coverage of the core compared to PCL/PVA nanofibers due to the high viscosity and low spinnability of the core polymer, collagen. The optimum voltage and feeding rate for the fabrication of nanofibers were found to be 16 kV and 1:3 (core:shell), respectively. Due to their secondary structure and their promising properties, PCL/Col nanofibers exhibited great potential for biomedical applications such as wound healing and drug delivery platforms. [ABSTRACT FROM AUTHOR]

Core-shell nanofibers for biomedical applications have been successfully prepared by emulsion electrospinning, utilizing the model drug Tetracycline hydrochloride (TCH) water solution as the "aqueous phase" and hydrophobic polymer solution as the "organic phase." The morphology of nanofibers was assessed by scanning electron microscopy (SEM) and the core-shell structure was confirmed by inverted fluorescence microscopy and transmission electron microscopy (TEM). The improved hydrophilicity might be caused by the presence of the emulsifier Span 80 on the surface of the nanofibers. The mechanical properties study showed that core-shell nanofibers membranes were softer and more elastic than blended nanofibers. In vitro drug release study showed that the TCH could release continuously for 34 days. The release mechanism of the nanofibers followed Fickian diffusion at low drug efficiency, but drug diffusion was the best fit with the First-order kinetic model when increasing drug loading rates. Overall, emulsion core-shell nanofibers could be used as a promising drug reservoir for sustained and continuous drug release behaviors. Meanwhile, the study of drug release kinetics was used in conjunction with model drug properties to develop a wider range of nanofibers carriers and biomaterials. [ABSTRACT FROM AUTHOR]

A coaxial nanofibrous scaffold of poly (ε-caprolactone) and gelatin/cellulose acetate encapsulating anti-inflammatory and antibacterial drugs was co-electrospun for skin tissue regeneration. Indomethacin and ciprofloxacin as model drugs were added to the core and the shell solutions, respectively. The effect of the drugs' presence and crosslinking on the scaffold properties was investigated. TEM images confirmed the core–shell structure of the scaffold. The fiber diameter and the pore size of the scaffold increased after crosslinking. The tensile properties of the scaffold improved after crosslinking. The crosslinked scaffold illustrated a higher rate of swelling, and a lower rate of degradation and drug release compared to the uncrosslinked one. Fitting the release data into the Peppas equation showed that Fickian diffusion was the dominant mechanism of drug release from the scaffolds. The results of biocompatibility evaluations showed no cytotoxicity and suitable adhesion and cell growth on the prepared core–shell structure. The antibacterial activity of the scaffolds was studied against one of the most common pathogens in skin wounds, where the existence of ciprofloxacin could prevent the growth of the Staphylococcus aureus bacteria around the scaffold. The obtained results suggested a new coaxial nanofibrous scaffold as a promising candidate for simultaneous tissue regeneration and controlled drug release. [ABSTRACT FROM AUTHOR]

Emulsion electrospinning emerges as a promising technique for producing core-shell nanofibers used in delivering bioactive compounds. This work aims to investigate the feasibility of employing octenylsuccinylated (OS) starch-based emulsions in electrospinning for the fabrication of these nanofibers. The influence of sunflower seed oil concentration, ranging from 5% to 50%, on the emulsions was systematically examined. Increasing the oil concentration affects several key characteristics of the emulsions. These changes include a rise in apparent viscosity (from 0.78 to 7.72 Pa·s at 100 s−1) and average droplet size (from 1.21 to 1.79 μm), as well as a decrease in conductivity (from 727 to 193 μs/cm), leading to a larger average diameter of electrospun fibers, which increased from 294 to 533 nm. Confocal laser scanning microscopy and transmission electron microscopy confirmed the core–shell structure of the fibers. Furthermore, the correlation between fiber size and emulsion properties was discussed, and it was noted that the average fiber diameter, loading capacity, and encapsulation efficiency were significantly affected by emulsion composition and properties. These insights contribute to our understanding of the emulsion electrospinning process and offer a valuable guidance for the development of OS starch-based core–shell electrospun fibers. [Display omitted] • Electrospinning of emulsions stabilized by OS starch and pullulan was studied. • Oil content significantly affected emulsions stability and average fiber diameter. • The core–shell structure of the fibers was confirmed by CLSM and TEM. • Loading capacity and encapsulation efficiency were affected by emulsion properties. [ABSTRACT FROM AUTHOR]

Fabrication of Core-shell nanofibrous mat which is a promising tool for a wide range of applications in tissue engineering can be developed using water in oil (W/O) or oil in water (O/W) emulsion electrospinning. In this study, for the first time, we fabricated an O/W emulsion-based electrospun core-shell mat using polycaprolactone (PCL) as a core and the blend solution of alginate (Alg) and polyethylene oxide (PEO) as shell material. To achieve a stable core-shell mat, firstly, Alg was modified with heat treatment to decrease the molecular weight of Alg. Then, to improve the chain flexibility of Alg, PEO as a second polymer was added to facilitate its electrospinnability. The different volume ratios of O/W were then fabricated by adding PCL to the Alg-PEO solution to find an optimized emulsion solution. The morphology, swelling, and porosity of the construct were evaluated. At the same time, the mechanical characteristic of fibers was evaluated in both dry and wet conditions. This study also examined cell-scaffold interactions to address the need for a scaffolding material to be suitable for tissue engineering and biomedical applications. Finally, the result exhibited a distinct core-shell structure with better mechanical properties compared to the Alg-PEO. [Display omitted] [ABSTRACT FROM AUTHOR]

In recent years, self-sensing composite materials based on the direct piezoelectric effect have attracted widespread interest as they combine the composite material's mechanical performances with the piezoelectric phase's sensing capability. In this context, piezoelectric nanofibers exhibit minimal impact on the mechanical structure of the composite – differently from bulky films or ceramic disks - and represent a promising strategy for robotic applications or wearable devices. This work aims to develop a self-sensing laminate based on piezoelectric core-shell nanofibers (PEDOT:PSS-based core and P(VDF-TrFE)-based shell). Each layer of the laminate is made of a flexible epoxy material and embeds aligned nanofibers. By orthogonally overlapping two layers, the intersection points of the matrix-like arrangement of the nanofibers generate a network of piezoelectric pixels, which are responsible for sensing. Such a self-sensing composite material exhibited a noticeable capability to recognize the exact position of a mechanical stimulus on its surface. [Display omitted] • Core-shell piezoelectric nanofibers were fabricated via coaxial electrospinning. • The nanofibers were embedded in a matrix-like disposition in a hosting material. • The intersection of orthogonal nanofibers generates a network of sensitive pixel. • The composite material is able to recognize the position of an impact on its surface. [ABSTRACT FROM AUTHOR]

To date, available review papers related to the electrospinning of biopolymers including polysaccharides for wound healing were focused on summarizing the process conditions for two candidates, namely chitosan and hyaluronic acid. However, most reviews lack the discussion of problems of hyaluronan and chitosan electrospun nanofibers for wound dressing applications. For this reason, it is required to update information by providing a comprehensive overview of all factors which may play a role in the electrospinning of hyaluronic acid and chitosan for applications of wound dressings. This review summarizes the fabricated chitosan and hyaluronic acid electrospun nanofibers as wound dressings in the last years, including methods of preparations of nanofibers and challenges for the electrospinning of both pure chitosan and hyaluronic acid and strategies how to overcome the existing difficulties. Moreover, in this review the biological roles and mechanisms of chitosan and hyaluronic acid in the wound healing process are explained including the advantages of nanofibers for ideal wound management using the common solvents, copolymers enhancing spinning process, and the most biologically active incorporated substances thereby providing drug delivery in wound healing. • Electrospun chitosan and hyaluronic acid nanofibers mimic the extracellular matrix. • High viscosity and ionic nature of both polymers limit their electrospinning. • The addition of another polymer improves properties of electrospun nanofibers. • Electrospinning facilitates the use of multicomponent nanofibers in medicine. [ABSTRACT FROM AUTHOR]

In the field of tissue engineering, the use of core-shell fibers represents an advantageous approach to protect and finely tune the release of bioactive compounds with the aim to regulate their efficacy. In this work, core-shell electrospun polycaprolactone nanofiber-based membranes, loaded with rifampicin and coated with silver nanoparticles, were developed and characterized. The membranes are composed by randomly oriented nanofibers with a homogeneous diameter, as demonstrated by scanning electron microscopy (SEM). An air-plasma treatment was applied to increase the hydrophilicity of the membranes as confirmed by contact angle measurements. The rifampicin release from untreated and air-plasma treated membranes, evaluated by UV spectrophotometry, displayed a similar and constant over-time release profile, demonstrating that the air-plasma treatment does not degrade the rifampicin, loaded in the core region of the nanofibers. The presence and the distribution of silver nanoparticles on the nanofiber surface were investigated by SEM and Energy Dispersive Spectroscopy. Moreover, SEM imaging demonstrated that the produced membranes possess a good stability over time, in terms of structure maintenance. The developed membranes showed a good biocompatibility towards murine fibroblasts, human osteosarcoma cells and urotheliocytes, reveling the absence of cytotoxic effects. Moreover, doble-functionalized membranes inhibit the growth of E. coli and S. aureus. Thanks to the possibilities offered by the coaxial electrospinning, the membranes here proposed are promising for several tissue engineering applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Electrospinning is a well-established method for the fabrication of polymer biomaterials, including those with core-shell nanofibers. The variability of structures presents a great range of opportunities in tissue engineering and drug delivery by incorporating biologically active molecules such as drugs, proteins, and growth factors and subsequent control of their release into the target microenvironment to achieve therapeutic effect. The object of study is non-woven core-shell PVA–PEG–SiO2@PVA–GO fiber mats assembled by the technology of coaxial electrospinning. The task of the core-shell fiber development was set to regulate the degradation process under external factors. The dual structure was modified with silica nanoparticles and graphene oxide to ensure the fiber integrity and stability. The influence of the nano additives and crosslinking conditions for the composite was investigated as a function of fiber diameter, hydrolysis, and mechanical properties. Tensile mechanical tests and water degradation tests were used to reveal the fracture and dissolution behavior of the fiber mats and bundles. The obtained fibers were visualized by confocal fluorescence microscopy to confirm the continuous core-shell structure and encapsulation feasibility for biologically active components, selectively in the fiber core and shell. The results provide a firm basis to draw the conclusion that electrospun core-shell fiber mats have tremendous potential for biomedical applications as drug carriers, photocatalysts, and wound dressings. [ABSTRACT FROM AUTHOR]

The application of all‐inorganic perovskite nanocrystals (PNCs) is considerably limited by their inherent instability under the ubiquitous environmental conditions with high water content, temperature, and UV intensity. The multiwalled carbon nanotubes (CNTs) are combined with polyacrylonitrile (PAN) for the first time to improve the uniform luminous performance and environmental stability of PNCs, attributing to the dense growth of PNC via lead ions bound with rich carbonylation on CNT surfaces, the excellent characteristics of CNTs (including hydrophobicity, electrical conductivity, specific heat, UV absorption capacity), the weather resistance of PAN polymer, and their synergistic effect. Here, via one‐step single‐nozzle electrospinning at room temperature, CNTs, PNCs, and PAN are comprised as core–shell nanofibers (i.e., CNTs/PNCs@PAN) with tunable emissions between 472 and 683 nm, covering the visible light range from blue to red. The photoluminescence intensity of CNTs/CsPbBr3@PAN can be 93%, 91%, and 91% of the initial value, respectively, after being immersed in water for 20 days, heated to 90 °C, and exposed to 365 nm light irradiation for 48 h, which are superior to those of the previously reported PNCs/PAN fibers. The ultrahigh water stability is further proven by CNTs/PNCs@PAN‐based sensor for rhodamine 6G solution fluorescence detection. [ABSTRACT FROM AUTHOR]

The synthesis of graphitic carbon nitride/cadmium sulfide core-shell nanofibers has been studied for the improved photodegradation of methylene blue (MB) dye. The enhancement in photocatalytic activity in g-C3N4@CdS core-shell nanostructures has been increased by controlling the thickness of the CdS shell. Additionally, the favorable bandgap, suitable band positions, and high thermal stability played an important role to enhance the photodegradation rate of catalysts. g-C3N4@CdS core-shell nanofiber arrays were synthesized by using a simple two-step process. g-C3N4 nanofiber (gcnf) was synthesized by using a simple polycondensation method and followed by a surface modification step for the deposition of CdS nanoparticles. The characterization of core-shell nanofibers and their photocatalytic activity was examined by powder X-ray diffraction, UV-Vis spectrophotometer, FESEM, EDS, and TEM microscopy. g-C3N4@CdS core-shell nanofibers (gcnf/CdS, 0.38; gcnf/CdS, 0.19; and gcnf/CdS, 0.09) showed enhanced photocatalytic degradation efficiency of ~ 98% in 40, 50, and 70 min, respectively. Pristine g-C3N4 nanofibers and CdS nanoparticles displayed the photodegradation efficiency of ~ 98% in 100 and 170 min, respectively. gcnf/CdS, 0.38 core-shell nanofibers (0.38 M of citric acid), offered the highest photodegradation rate of 0.0624 min−1, which is ~ 2.5- and 3-fold higher than pristine g-C3N4 nanofibers and CdS nanoparticles, respectively. The increase in the photodegradation rate of the g-C3N4@CdS core-shell nanostructure is due to the synergetic effect of g-C3N4 and CdS. Thus, the present work highlights the enhanced photocatalytic activity and stability of g-C3N4@CdS core-shell nanofibers and found to be useful in energy harvesting and environmental remediation applications. [ABSTRACT FROM AUTHOR]

In this study, a novel one-step coaxial electrospinning process is employed to fabricate shell-core structure fibers choosing Chlorella pyrenoidosa proteins (CP) as the core material. These nanofibers, serving as the wall material for probiotic encapsulation, aimed to enhance the stability and antioxidant activity of probiotics in food processing, storage, and gastrointestinal environments under sensitive conditions. Morphological analysis was used to explore the beads-on-a-string morphology and core-shell structure of the electrospun fibers. Probiotics were successfully encapsulated within the fibers (7.97 log CFU/g), exhibiting a well-oriented structure along the distributed fibers. Compared to free probiotics and uniaxial fibers loaded with probiotics, encapsulation within microalgae proteins/alginate core-shell structure nanofibers significantly enhanced the probiotic cells' tolerance to simulated gastrointestinal conditions (p < 0.05). Thermal analysis indicated that microalgae proteins/alginate core-shell structure nanofibers displayed superior thermal stability compared to uniaxial fibers. The introduction of CP resulted in a 50 % increase in the antioxidant capacity of probiotics-loaded microalgae proteins/alginate nanofibers compared to uniaxial alginate nanofibers, with minimal loss of viability (0.8 log CFU/g) after 28 days of storage at 4 °C. In summary, this dual-layer carrier holds immense potential in probiotic encapsulation and enhancing their resistance to harsh conditions. Novel one-step coaxial electrospinning process to fabricate shell-core structured fibers based on CP/alginate complexes, aiming for enhancing the stability and antioxidant activity of probiotics in food processing, storage, and gastrointestinal environments. [Display omitted] • Novel core-shell nanofibers fabricated with Chlorella pyrenoidosa proteins (CP)/alginate complexes. • The pH-responsive core-shell nanofibers significantly improved the gastrointestinal survival rate of probiotics. • The incorporation of CP enhanced the antioxidant properties of the probiotics-loaded nanofibers. • CP extended probiotics' activity by providing nutritional support during storage. [ABSTRACT FROM AUTHOR]

Liposomes and nanofibers have been implemented as efficacious vehicles for delivering anticancer drugs. With this view, this study explores the antiproliferative efficacy and apoptosis induction in leukemia cancer cells utilizing irinotecan-loaded liposome-embedded nanofibers fabricated from chitosan, a biological source. Specifically, we investigate the effectiveness of poly(ε-caprolactone) (PCL)/chitosan (CS) (core)/irinotecan (CPT)nanofibers (termed PCL-CS10 CPT), PCL/chitosan/irinotecan (core)/PCL/chitosan (shell) nanofibers (termed CS/CPT/PCL/CS), and irinotecan-coloaded liposome-incorporated PCL/chitosan-chitosan nanofibers (termed CPT@Lipo/CS/PCL/CS) in releasing irinotecan in a controlled manner and treating leukemia cancer. The fabricated formulations were characterized utilizing Fourier transform infrared analysis, transmission electron microscopy, scanning electron microscopy, dynamic light scattering, zeta potential, and polydispersity index. Irinotecan was released in a controlled manner from nanofibers filled with liposomes over 30 days. The cell viability of the fabricated nanofibrous materials toward Human umbilical vein endothelial cells (HUVECs) non-cancerous cells after 168 h was >98 % ± 1 %. The CPT@Lipo/CS/PCL/CS nanofibers achieved maximal cytotoxicity of 85 % ± 2.5 % against K562 leukemia cancer cells. The CPT@Lipo/CS/PCL/CS NFs exhibit a three-stage drug release pattern and demonstrate significant in vitro cytotoxicity. These findings indicate the potential of these liposome-incorporated core-shell nanofibers for future cancer therapy. [ABSTRACT FROM AUTHOR]

Protective coatings are used as a corrosion mitigation strategy in many industries. However, damages on transport, installation, and during the service life can expose the metal, leading to failures. Self–healing materials can address this issue by recovering their properties and functionality post-damage. Herein, it was developed an extrinsic self-healing coating by incorporating core–shell nanofibers obtained by coaxial electrospinning. Overcoming the non–spinnability of organosilane compounds, a one–trigger component healing agent was achieved. Additionally, scalability limitations for self-healing coatings were defeated by implementing a viable technique for large-scale structures – Spray painting. The final protective and healing behaviour was investigated by electrochemical and salt spray tests. Following damage, the immediate healing response reached 97.5 %, initiated solely by water. Low capacitance values for the developed coating indicated a robust protective barrier. Furthermore, the self-healing coating efficiently protected steel from corrosion in the salt spray test. The results obtained showed a promising future in using core–shell nanofibers to enhance the durability and protective capabilities of coatings for offshore facilities. [Display omitted] • A corrosion protective coating with extrinsic self-healing agent as corrosion inhibitor was prepared. • Core–shell nanofibers enabled a one-component healing response, autonomously after a damage event. • The self–healing coating with the nanofibers was applied via Spray painting. • Effective protection against corrosion after damage with up to 97.5 % healing response. [ABSTRACT FROM AUTHOR]

Recent research places significant importance on the development of innovative nanocomposites for photoelectrochemical applications. This paper presents the fabrication, characterization, and possible photoelectrochemical applications of novel ZnFe 2 O 4 /ZnO core-shell nanofibers. These core-shell nanofibers were fabricated through co-axial electrospinning using PVP solutions containing iron and zinc nitrate precursors for the core and shell. The structural and optical properties of ZnFe 2 O 4 /ZnO core-shell nanofibers were examined through TEM, SEM, XRD, FTIR, Raman spectroscopy, and diffuse reflectance spectroscopy. This comprehensive analysis unveiled that the development of core and shell characteristics was notably influenced by the interdiffusion of [Fe]/[Zn] during the annealing process. The photoelectrochemical properties of ZnFe 2 O 4 /ZnO core-shell nanofibers were assessed through electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and the Mott-Schottky method. These core-shell nanofibers demonstrated a robust electrochemical response to visible light. Photocurrent and photoconversion efficiency of the core-shell nanofibers were calculated and compared with the corresponding values for core-shell nanoparticles. The mechanisms underlying the structural, optical, and photoelectrochemical properties of ZnFe 2 O 4 /ZnO core-shell nanofibers were discussed. These advanced nanofibers hold potential applications in photocatalysis, photovoltaics, and energy storage, making this research timely and crucial for advancing sustainable energy technologies and environmental remediation efforts. [Display omitted] • Novel ZnFe 2 O 4 /ZnO core-shell nanofibers were produced by co-axial electrospinning. • ZnFe 2 O 4 /ZnO core-shell nanofibers showed significant response to visible light • Dark current in ZnFe 2 O 4 /ZnO core-shell nanofibers was significantly higher than of core-shell nanoparticles. • Photocurrent response and photoconversion efficiency were better than those of core-shell nanoparticles.. [ABSTRACT FROM AUTHOR]

In this study, coaxial electrospinning is employed to make core-shell fibers, which represents a major advance in biomaterial innovation. Fibers that combine a protective shell and a therapeutic agent-loaded core, herald a revolutionary era in tissue engineering and wound care. Besides supporting cell growth, these fibers also preserve sterility, which makes them ideal for advanced wound dressings. We used embelin as the basis for this study because of its natural antibacterial properties. Its effectiveness in inhibiting the growth of bacteria made it the ideal candidate for our research. We have synthesized core-shell nanofibers that contain Sodium Alginate (SAL) in a Poly (ethylene oxide) (PEO) shell and Embelin in a Poly (3-hydroxybutyric acid) (PHB) core, which exhibit the homogeneity and flawless structure required for biomedical applications. When using SAL-PEO and EMB-PHB solutions dissolved in 1,1,1,3,3,3 hexafluoro-2-propanol (HFIP), high consistency in results can be achieved. A biocompatibility study was conducted using NIH-3T3 fibroblasts, which demonstrated remarkable adhesion and proliferation, with over 95 % growth supporting both PHB + SAL-PEO and EMB-PHB + SAL-PEO fibers. In addition, the scaffold loaded with Embelin shows strong antibacterial activity and cytocompatibility. The combined activity demonstrates the potential of EMB-PHB + SAL-PEO fibers in wound healing, where tissue regeneration and preservation of sterility are crucial. The optimized concentration of Embelin within these scaffolds demonstrates robust antibacterial efficacy while exhibiting minimal toxicity, thus positioning them as highly promising candidates for a wide range of biological applications, including wound healing. Electrospinning process of embelin-loaded core-shell nanofibrous mats - Created with BioRender.com (2024). [Display omitted] • Embelin-loaded core-shell nanofibers were fabricated using electrospinning process. • The effective antibacterial activity has been confirmed against bacterial strains. • Cell adhesion study confirmed the biocompatibility of the nanofibers. • Synergistic action of embelin-loaded components effectively promotes wound healing. [ABSTRACT FROM AUTHOR]

Core-shell nanofibers have grown in popularity over the last decade owing to their special features and their many applications in biomedicine. They can be produced by electrospinning of immiscible polymer blends or emulsions through a single nozzle or by electrospinning using a coaxial nozzle. Several of the electrospinning parameters allow great versatility for the compositions and diameters of core-shell nanofibers to be produced. Morphology of core-shell nanofibers can be investigated using transmission electron microscopy and, in some cases, scanning electron microscopy. Several studies have shown that core-shell nanofibers have some advantages over monolithic nanofibers, such as better drug, protein, gene or probiotic incorporation into the nanofibers, greater control over drug release, and maintenance of protein structure and activity during electrospinning. We herein review the production and characterization of core-shell nanofibers, the critical parameters that affect their development, and their advantages as delivery systems.

Over the past several decades, the fabrication of novel ceramic nanofibers applicable in different areas has been a frequent focus of scientists around the world. Aiming to introduce novel ceramic core-shell nanofibers as a magnetic solid acid catalyst, Fe2O3@SiO2–SO3H magnetic nanofibers were prepared in this study using a modification of Fe2O3@SiO2 core-shell nanofibers with chlorosulfonic acid to increase the acidic properties of these ceramic nanofibers. The products were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscope (EDS), vibrating sample magnetometer (VSM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The prepared nanofibers were used as catalysts in formamide and formamidine synthesis. The treatment of aqueous formic acid using diverse amines with a catalytic amount of Fe2O3@SiO2–SO3H nanofibers as a reusable, magnetic and heterogeneous catalyst produced high yields of corresponding formamides at room temperature. Likewise, the reaction of diverse amines with triethyl orthoformate led to the synthesis of formamidine derivatives in excellent yields using this novel catalyst. The catalytic system was able to be recovered and reused at least five times without any catalytic activity loss. Thus, novel core-shell nanofibers can act as efficient solid acid catalysts in different organic reactions capable of being reused several times due to their easy separation by applying magnet.

The folic acid (FA) and doxorubicin (DOX) have been doped into the g‐C3N4/MoS2 incorporated‐chitosan/ethyl cellulose (EC) core‐shell nanofibers for targeted delivery of FA and DOX against HeLa and MCF‐7 cell lines. The g‐C3N4/MoS2 nanosheets and core‐shell nanofibers were characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV–Vis tests. The drug loading factor, the degradation rate, and the DOX and FA release behavior from core‐shell nanofibers have been investigated. The pharmacokinetic results revealed the linear release with non‐Fickian diffusion of the both anticancer drugs from nanofibers during 7 days. The DAPI staining and MTT assays of the nanofibers immersed in MCF‐7 and HeLa cell lines were studied to determine the potential of DOX and FA doped‐core‐shell nanofibrous matrix for MCF‐7 and HeLa cells death in vitro. The maximum MCF‐7 and HeLa cells death percentages were found to be 89 and 85%, respectively, using EC/chitosan/g‐C3N4/MoS2/DOX/FA core‐shell nanofibers after 7 days. The high activity of g‐C3N4/MoS2/DOX/FA loaded‐core‐shell nanofibers for studied cancer cells killing was achieved. [ABSTRACT FROM AUTHOR]

Self‐healing epoxy composite working at subroom temperature could be useful in aerospace industry and wind turbine blades. In this research, hybrid core‐shell nanofibers mat containing epoxy resin and mercaptan was embedded in epoxy matrix to investigate repeated self‐healing ability of the fabricated composite at subroom temperature (10°C). The results of three‐point bending test illustrated that the release of epoxy resin and mercaptan into cracks and curing reaction between them could restore flexural properties of the composite. In fourth bending cycle, flexural modulus of composite reinforced by hybrid mat and unreinforced epoxy (without nanofiber) was reduced 6% and 24%, respectively. In addition, hybrid mat reinforced composite was broken at fifth bending cycle whereas for unreinforced epoxy specimen occurred at fourth bending cycle. Non‐isothermal differential scanning calorimetry thermograms after each three‐point bending cycle of hybrid mat reinforced composite showed an exothermic peak centered about 64°C. This peak is related to epoxy and mercaptan reaction that could confirm self‐healing ability of hybrid core‐shell nanofibers mat. Extraction results, FTIR analysis, and three‐point bending test showed the stability of epoxy and mercaptan into nanofibers during 8 months. [ABSTRACT FROM AUTHOR]

Poly(lactic acid)-gelatin (PLA-GT) core-shell nanofibers were prepared successfully via coaxial electrospinning method using new solvents for dissolving core and shell polymers, dimethylformamide for dissolving PLA and concentrated acetic acid for dissolving gelatin. Transmission electron microscopy (TEM) and attenuated total reflectance Fourier transform spectroscopy (ATR-FTIR) were used to confirm the formation of core-shell structure in the nanofibers with these new solvents. Morphological investigation of the as-spun nanofibers was carried out using scanning electron microscopy (SEM) which revealed a bead-free ribbon-like morphology for PLA-GT core-shell structured nanofibers with an average diameter of 347 ± 88 nm. Although compositional analysis by differential scanning calorimetry (DSC) indicated that PLA content in the prepared core-shell nanofibers was low (approximately 7.8%), the PLA presence in the nanofibers' core could improve their mechanical properties. The nanofibers' shell was crosslinked by glutaraldehyde. In addition to highly preserving nanofibrous and porous structures of the mat, the crosslinking treatment strengthened core-shell nanofibers significantly. In vitro degradation test showed that even after 11 days, the fibrous structure of crosslinked core-shell mat was maintained. The fabricated PLA-GT core-shell nanofibers have potentials in some biomedical applications. [ABSTRACT FROM AUTHOR]

1D semiconducting nanomaterials are promising candidates for wearable electronic devices, in which variability of form (i.e., flexibility and stretchability) is a crucial factor for achieving stable operation during a user's physical activity. Although many stretchable 1D electronic materials have been suggested, they mainly rely on structural engineering, rather than the intrinsic stretchability of the materials, and hence suffer from electrical instability under mechanical deformation. In this work, stretchable core–shell polymeric nanofibers (NFs) are fabricated using coaxial electrospinning. The stretchable core–shell NFs, which consist of a stretchable core and a semiconducting shell, provide both mechanical robustness and superior electrical properties under external strain. The stretchable core–shell NF‐based transistors show high operational stability at up to 30% mechanical strain. Furthermore, fully stretchable organic field‐effect transistors fabricated using core–shell NFs and stretchable conductors exhibit stable operation and high optical transparency (71% of transmittance at a wavelength of 550 nm). The core–shell NFs also exhibit excellent optoelectronic properties, including a maximum light responsivity (R) of 84.2 A W−1 and an external quantum efficiency (EQE) of 178.6%, under illumination at a wavelength of 585 nm. The results demonstrate a viable approach to fabricating wearable electronic devices using stretchable core–shell polymeric NFs. [ABSTRACT FROM AUTHOR]

In this work, polyacrylonitrile (PAN) nanofiber mats coated with conductive polypyrrole layers were produced at the surface of gold electrodes by a two-step approach combining electrospinning and vapor phase polymerization. In the first step, smooth and uniform PAN fibers exhibiting an average diameter of 650 ± 10 nm were generated through electrospinning of 12 wt% PAN solutions. The electrospun PAN fibers were impregnated with iron(III)tosylate (FeTos), annealed at 70°C and used as a robust and stable template for the growth of a thin layer of conductive polymer by co-polymerizing pyrrole (Py) and pyrrole-3-carboyxylic acid (Py3COOH) vapors under nitrogen atmosphere. The carboxyl groups introduced in polypyrrole coatings enabled further covalent binding of a model enzyme, glucose oxidase. The effect of different parameters (concentration of FeTos into the immersion solution, time of polymerization, Py/Py3COOH molar ratio) on the PAN/PPy/PPy3COOH/GOx impedimetric biosensor response was investigated. In the best conditions tested (immersion of the PAN fibers into 20 wt% FeTos solution, polymerization time: 30 min, 1:2 Py/Py3COOH ratio), the biosensor response was linear in a wide range of glucose concentration (20 nM−2μM) and selective toward ascorbic and uric acids. A very low limit of detection (2 nM) compared to those already reported in the literature was achieved. This value enables the determination of glucose in human serum after a large dilution of the sample (normal concentrations: 3.6 mM−6.1 mM range).

Electrospinning is a well-established method for the fabrication of polymer biomaterials, including those with core-shell nanofibers. The variability of structures presents a great range of opportunities in tissue engineering and drug delivery by incorporating biologically active molecules such as drugs, proteins, and growth factors and subsequent control of their release into the target microenvironment to achieve therapeutic effect. The object of study is non-woven core-shell PVA–PEG–SiO2@PVA–GO fiber mats assembled by the technology of coaxial electrospinning. The task of the core-shell fiber development was set to regulate the degradation process under external factors. The dual structure was modified with silica nanoparticles and graphene oxide to ensure the fiber integrity and stability. The influence of the nano additives and crosslinking conditions for the composite was investigated as a function of fiber diameter, hydrolysis, and mechanical properties. Tensile mechanical tests and water degradation tests were used to reveal the fracture and dissolution behavior of the fiber mats and bundles. The obtained fibers were visualized by confocal fluorescence microscopy to confirm the continuous core-shell structure and encapsulation feasibility for biologically active components, selectively in the fiber core and shell. The results provide a firm basis to draw the conclusion that electrospun core-shell fiber mats have tremendous potential for biomedical applications as drug carriers, photocatalysts, and wound dressings.