Coaxial Electrospinning Method Research Articles

Interconnected Hollow Porous Polyacrylonitrile-Based Electrolyte Membrane for a Quasi-Solid-State Flexible Zinc-Air Battery with Ultralong Lifetime.

Quasi-solid-state flexible zinc-air batteries (FZABs) have received enormous attention due to their low cost and high safety. However, the constraints in lifetime resulting from the lack of stable quasi-solid-state electrolyte membranes and efficient bifunctional electrocatalysts toward oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) hinder the large-scale manufacture and commercialization of FZABs to power electric devices. Herein, a polyacrylonitrile (PAN)-based membrane (HPPANP) fabricated via facile coaxial electrospinning, water dissolution, lyophilization, and KOH preimmersion method was utilized as the quasi-solid-state electrolyte membrane. The interconnected hollow porous structure based on PAN nanofibers endows HPPANP with outstanding electrolyte-uptake/retention capabilities for high ionic conductivity and nanolevel wetted electrolyte/anode interface for uniform Zn dissolution/deposition, thus prolonging the lifespan of the FZABs. In addition, the in situ alkaline hydrolysis of KOH solution supplies HPPANP with abundant oxygen-containing groups, which also improves its ionic conductivity. Additionally, we synthesized a Co/N-doped hollow carbon sphere (CoN-CS) electrocatalyst that exhibits superior ORR and OER electrocatalytic activities with a low potential difference (ΔE) of 0.73 V. Such favorable ORR and OER performances can be mainly attributed to the hierarchical hollow micro/nanostructures with abundant active sites, long-term stability, and favorable electron/ion diffusion pathway. As a result, the assembled FZAB equipped with the CoN-CS catalyst and HPPANP displays high power density (123.8 mW cm-2) and preferable long-term cycling performance (more than 50 h at 3 mA cm-2).

Enhancing structural strength and improving cell survival through Polycaprolactone/(gelatin/hydroxyapatite) Core‐Shell nanofibers for tissue engineering

AbstractBone tissue engineering is a practical approach to repairing broken or damaged bones that combines scaffold, cells, and growth factors for treatment. In this study, polycaprolactone (PCL)/gelatin (Ge)/hydroxyapatite (HA) core‐shell nanocomposites have been produced by the coaxial electrospinning method. Coaxial electrospinning is an efficient method for scaffold preparation to provide an interconnected porous fibrous scaffold. The prepared nanocomposite simultaneously benefited from the good mechanical behavior of the core PCL polymer. The desired biological properties also originated from the outer layer of the Ge/HA nanocomposite. Nanofibrous scaffolds' properties were characterized using SEM, TEM, FTIR, TGA, DSC, tensile test, contact angle, and MTT assay. The morphology of the as‐electrospun nanofibers was investigated using SEM and TEM, which revealed a defect‐less fibrous morphology. TEM images showed the core‐shell structure of the prepared scaffold nanofibers. The contact angle test showed that the presence of HA nanoparticles has improved the wettability of fibrous composites. In addition, HA nanoparticles could effectively strengthen the polymer scaffolds. The highest UTS value of 4.1 MPa was obtained in the PCL/(Ge+10%HA) sample. The cytotoxicity results revealed that the prepared scaffolds were utterly biocompatible. Moreover, significant cell proliferation of osteosarcoma cells was observed at high HA contents. The interconnected pores allowed cells to migrate into the scaffolds and grow inside. Based on the obtained results, PCL/(Ge/ HA) core‐shell nanofibers could be a promising candidate for bone scaffolds.

Tuning the ferromagnetic and ferroelectric properties of BiFeO3 multiferroic nanofibers by Co/Ni spinel ferrites

BiFeO 3 –(Co/Ni)Fe 2 O 4 (BFO–(C/N)FO) multiferroic nanofibers were synthesized using a self-assembly coaxial electrospinning technique. The structure, exchange bias effect, ferromagnetic, and ferroelectric properties were investigated using various physical and chemical characterization approaches. The coexistence of a spinel–perovskite mixed structure was verified in (BFO–(C/N)FO) nanofibers by X-ray diffraction and X-ray photoelectron spectroscopy. Raman spectra revealed a distorted crystal structure or more complex phase configurations with overlapping features. Compared to the pure BFO nanofibers, the magnetic properties showed a significantly increase after recombination. BFO–NFO nanofibers exhibited higher exchange coupling through switching field distribution analysis. The ferroelectric properties of the composite nanofibers were considerably changed compared to pure BFO nanofibers, which can be attributed to the presence of impurities (Bi 2 Fe 4 O 9 ) and the asymmetrical spin in spinel ferrites. The BFO–CFO nanofibers exhibited larger leakage current and coercive electric field than the other two types of nanofibers. Hence, coupling of the structural distortion and crystal phases are important approaches in altering the ferroelectric and ferromagnetic properties. These results suggest that the BFO–(C/N)FO nanofibers have potential applications in multifunctional nanodevices. • Pure BFO, CFO, NFO, BFO–NFO, and BFO–CFO nanofibers were synthesized using the self-assembly coaxial electrospinning method, and the influence of Co/Ni spinel ferrites equivalent co-composite on the ferromagnetic and ferroelectric properties of BFO nanofibers was investigated systematically. The four phases such as BiFeO 3 , CoFe 2 O 4 (NiFe 2 O 4 ), Bi 2 Fe 4 O 9 and a little Bi 2 O 3 (BFO-CFO)are existed in BFO-C/NFO nanofibersand the phases percentage ratio were calculated. • Meanwhile,the Mr and Hc values for the BFO–NFO and BFO–CFO nanofibers were 12.5 emu/g and 864.7 Oe and 15.8 emu/g and 1326.9 Oe, respectively, which were higher than that of the pure BFO nanofibers. • Besides, the reason for polarization unsaturation of BFO–C/NFO nanofibers was related to the addition of certain amount of impurities (Bi2Fe4O9). • The results imply that the recombination between BFO and CFO/NFO results in significant high leakage current density.

Impedance amelioration of coaxial-electrospun TiO2@Fe/C@TiO2 vesicular carbon microtubes with dielectric-magnetic synergy toward highly efficient microwave absorption

An impedance-optimized hierarchical TiO 2 @Fe/C@TiO 2 vesicular carbon microtube is constructed for the first time via coaxial electrospinning and solvothermal method. Benefit from the integration of cavities, highly dispersed magnetic nanoparticles, and dielectric coating, the impedance is effectively improved by dielectric-magnetic synergy. The unique structure simultaneously fulfills a dual-network of micron-scale magnetic interaction and charge transfer, embedding the composite with enhanced magnetic and dielectric loss. The interfacial polarization and multiple reflections further promote microwave absorption. • 1D vesicular structure was successfully constructed via coaxial electrospinning. • Structural and compositional integration progressively improved impedance. • Strong magnetic-dielectric synergy of quaternary components in this absorber. • Electron holography confirmed magnetic coupling and charge transfer dual-network. Impedance matching ( Z ) is a key issue requested by high-efficient microwave absorption materials, which remains a major challenge. Lacking magnetic loss capacity and electromagnetic impedance balance, the microwave attenuation capacity of carbon-based absorbers urgently needs to be improved. Herein, a TiO 2 @Fe/C@TiO 2 vesicular carbon microtube was reasonably constructed by coaxial electrospinning. The characteristic impedance was gradually improved by introducing cavities, magnetic Fe particles and dielectric TiO 2 coating. The composite achieves an enhanced microwave performance with a maximum reflection loss of as strong as − 60.98 dB and a broad absorption bandwidth of 4.8 GHz at only 2.0 mm thickness. Such a well-integrated hierarchically vesicular carbon microtube with a tubular porous structure endows the assembly with high magnetic anisotropy and multiple interfaces, further offers the composites: i) the dual-networks of micron-scale 1D anisotropic magnetic coupling and charge conduction, ii) dielectric-magnetic synergy of quaternary components, iii) progressively matched impedance, proved by micromagnetic simulation and electron holography. This finding might have great significance in the impedance matching control of high-performance microwave absorbents.

Janus Hollow Nanofiber with Bifunctional Oxygen Electrocatalyst for Rechargeable Zn-Air Battery.

Zn-air battery technologies have received increasing attention, while the application is hindered by the sluggish kinetics of the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). In order to explore an efficient method to fabricate a high-performance electrocatalyst via modification of advanced nanostructure, a coaxial electrospinning method with in-situ synthesis and subsequent carbonization to construct 3D flexible Janus-like electrocatalysts is developed. The resulting Janus nanofibers have a unique core-shell hollow fiber structure, where NiFe alloy electrocatalysts supported by N-doped carbon nanobelt are located on the inner wall of the carbon layer, and leaf-like Co-N nanosheets are anchored on the outer wall of the carbon layer. As a result, the electrocatalyst exhibits excellent bifunctional catalytic performance for ORR and OER, demonstrating the small potential gap value of 0.73V between the ORR half-wave potential and the OER potential at 10mA cm-2 , which is even comparable to the mixed commercial noble catalyst with 20% Pt/C and RuO2 . The rechargeable Zn-air battery is constructed and displays a large open-circuit voltage of 1.44V, high power density (130mW cm-2 ) and energy density (874Wh kg-1 ). This study provides a concept to synthesize and construct high performance bifunctional electrocatalysts.

Enhanced Output Performance of Piezoelectric Nanogenerators by Tb-Modified (BaCa)(ZrTi)O3 and 3D Core/shell Structure Design with PVDF Composite Spinning for Microenergy Harvesting.

Flexible piezoelectric nanogenerators (PENG) have attracted great attention due to their stable electrical output and promising applications in the Internet of Things. To develop a high-performance PENG, a significant relationship among material, structure, and performance precipitates us to design its rational construction. Herein, Tb-modified (BaCa)(ZrTi)O3 (BCZT) particles have been fabricated into a 3D structure (3D-Tb-BCZT) by the freeze-drying method, and the innovative 3D core/shell structure of 3D-Tb-BCZT-coated 3D-Tb-BCZT/PVDF composite fibers was carried out through the coaxial electrospinning method. The innovative structure can significantly enhance correlation between adjacent piezoelectric particles and improve stress-transfer efficiency, which can be proven by experimental results and COMSOL simulation. As a result, the improved PENG shows a significantly enhanced output of 48.5 V and 3.35 μA as compared to the PENG with the conventional electrospinning process (15.6 V and 1.32 μA). Due to the advantages of light weight, soft flexibility, and high deformation sensitivity of composite fibers, PENG-based fibers can harvest various mechanical energies in daily life such as biological motion, noise vibration, and wind energies. More importantly, the PENG is sufficient enough to power an electronic device for sustained operation by capturing wind energies through power management circuit design, which further promotes the practical application process of a self-powered system.

Electrospun polyacrylonitrile-based lace nanostructures and their Cu(Ⅱ) adsorption

High performance nanostructures for efficient heavy metal treatment are highly desired in our daily life. A functionalized porous nanofibrous membrane loaded with MgO nanoparticles prepared by coaxial electrospinning and post-processing method was studied to remove copper ions from aqueous solutions. The solid core layer is used to support the functional layer of the sheath with lace-like porous structure, and to obtain the composite nanofiber membrane with super adsorption performance. The functional fiber membrane has a larger specific surface area, a more uniform diameter distribution and surface pores than other nanofibers, moreover, showing the dual advantages of good mechanical properties and hydrophilicity. Adsorption of copper ions reached equilibrium within 3 h with an optimal adsorption pH of 5 and a maximum adsorption capacity of 354 mg/g. The pseudo-second-order kinetic model and the Langmuir model can well describe the single-layer chemisorption process between copper ion and functional membrane. After the functional fiber membrane was repeatedly used for 5 times, the adsorption removal efficiency remained at 70%, which indicates that the recycling performance was good. The functionalized nanofiber membrane has a simple preparation and high removal efficiency, and is an effective material that can address heavy metal-polluted water.

Tailored construction of one-dimensional TiO2/Au nanofibers: Validation of an analytical assay for detection of diphenylamine in food samples

We report a one-dimensional titanium dioxide encapsulated with gold heterojunction nanofibers (TiO2/Au NFs) as robust electrocatalysts for electrochemical detection of diphenylamine (DPA). A TiO2/Au NFs were successfully synthesized by a coaxial electrospinning method. The formation of TiO2/Au NFs was confirmed by various analytical and spectroscopic approaches. The fabricated TiO2/Au NFs modified screen-printed carbon electrodes (SPCE) exhibit a well-enhanced detection activity towards DPA sensing as compared to other electrodes. Under the experimental conditions, the proposed electrode leading to the sensing range from 0.05 to 60 µM with a detection limit of 0.009 µM was obtained for the DPA detection. Moreover, the TiO2/Au NFs/SPCE showed good selectivity towards the electrochemical oxidation of DPA. Interestingly, the TiO2/Au NFs modified electrode was then applied to detect the effect of DPA on spiked content in the food samples.

Fabrication and characterization of chitosan-polycaprolactone core-shell nanofibers containing tetracycline hydrochloride

Chitosan-polycaprolactone (CS-PCL) core-shell structured nanofibers, in which CS and PCL respectively form the core and shell layers, were electrospun by coaxial electrospinning method. In this regard, three sets of core-shell nanofiber samples were prepared and the best one with desirable morphology, smooth surface, and without beads was characterized. Then tetracycline hydrochloride (TCH) is embedded in the CS core. An attempt has been made to prove the formation of the core-shell structure and encapsulation of the drug by water contact angle (WCA) measurements and attenuated total reflectance Fourier transform spectroscopy (ATR-FTIR). Transmission electron microscopy (TEM) was also used for the validation of the core-shell structure. Morphological investigations were conducted using scanning electron microscopy (SEM) which showed smooth CS-PCL nanofibers without any beads and with an average diameter of 285 ± 75 nm. Compositional analysis was carried out by differential scanning calorimetry (DSC) which indicated that about 64.3% of the prepared CS-PCL core-shell nanofibers were composed of PCL constituent. Also, In-vitro degradation of the nanofibers in the Phosphate Buffered Saline (PBS) solution was evaluated. In comparison to the blend nanofibers, TCH-loaded CS-PCL core-shell nanofibers showed a two-stage release of the drug, an initial burst release stage followed by a sustained release. Moreover, the antibacterial activity of CS-PCL core-shell nanofibers loaded with TCH was confirmed; hence, it has some potential applications in biomedical areas such as in wound dressing and drug delivery systems.

The experimental study of regeneration of annulus fibrosus using decellularized annulus fibrosus matrix/poly(ether carbonate urethane)urea-blended fibrous scaffolds with varying elastic moduli.

Although tissue engineering has attracted increasing attention for the treatment of degenerative intervertebral disc disease, the biochemical properties, structural organization, and mechanical characteristics of annulus fibrosus tissue have restricted progress. Differentiation of annulus fibrosus-derived stem cells (AFSCs) can be regulated by the elasticity of substrates such as poly(ether carbonate urethane)urea (PECUU). Decellularized annulus fibrosus matrix (DAFM) has good biocompatibility and biodegradability, making it suitable for cell adhesion, proliferation, and differentiation. In this study, we used a coaxial electrospinning method to synthesize DAFM/PECUU-blended fibrous scaffolds with elasticities approximating that of native inner and outer annulus fibrosus tissue. AFSCs cultured on DAFM/PECUU-blended fibrous scaffolds exhibited increased collagen type I gene expression with increasing elasticity of the scaffold material; notably, collagen type II and aggrecan gene expression exhibited the opposite trend. Regarding extracellular matrix secretion, collagen type I content gradually increased with substrate elasticity, while collagen type II and aggrecan contents decreased. In vivo evaluations employing magnetic resonance imaging, hematoxylin and eosin staining, and immunohistochemistry indicated that DAFM/PECUU-blended fibrous scaffolds could effectively repair defects of annulus fibrosus tissue. Our findings provide a theoretical and practical basis for the development of bionic annulus fibrosus tissue that closely mimics the biological properties, mechanical function, and matrix composition of native tissue.

Impact-resistant membranes from electrospun fibers with a shear-thickening core

Shear thickening fluid (STF) has great application potentials in the development of soft armors due to their unique properties. In this present study, the coaxial electrospinning method was used for the first time, using STF as the core of the composite fiber and polyketone (PK) as the sheath to fabricate a soft, foldable and impact-resistant fiber membrane with a mesh structure. The morphology, structure, chemical components, and impact resistance of the fiber membrane were characterized in detail. A core/shell structure was observed in the fiber cross section clearly. The impact resistance of the composite fibers (core to sheath ratio = 1:4, STF content = 46.2%), was about 33.3% higher than that of pure PK fibers without a core. When only one layer of the composite fibers (areal density = 60 g/m2) was added as an interlayer to two layers of aramid 1414 fibers, the impact resistance of the fabric increased by 18.8%. When spray coating resin was used in combination with only one layer of the composite fibers (areal density = 60 g/m2), the impact resistance of the fabric was enhanced by 27.8%. Therefore, the resultant fiber membrane has broad application prospects as an impact protection material.

Adsorption and sustained release of doxorubicin from N-carboxymethyl chitosan/polyvinyl alcohol/poly(ε-caprolactone) composite and core-shell nanofibers

The core-shell nanofibers, produced by the coaxial electrospinning method, are good candidates for delivery of anticancer drugs due to their continuous release without initial burst release. In this work, the N-carboxymethyl chitosan (N-CMCS)-polyvinyl alcohol (PVA)/poly(ε-caprolactone) (PCL) composite and core-shell nanofibers were prepared by two-nozzle and coaxial electrospinning techniques, respectively. Doxorubicin (DOX) as an anticancer drug was loaded into the N-CMCS/PVA/PCL nanofibers fabricated by two-nozzle and coaxial electrospinning. The performance of nanofibers was compared for the adsorption and controlled release of DOX against MCF-7 breast cancer cells death in vitro. The produced fibers were characterized using FTIR, SEM, and TEM analysis. Drug encapsulation efficiency, drug content, and drug release studies were evaluated. The DOX molecules were released from coaxial nanofibers without burst release under extended-release during 20, and 10 days under pH values of 7.4 and 5.5, respectively. The initial burst release at the first hours following by the sustained release of DOX was achieved for composite nanofibers during 11 and 3 days under physiological and acidic pH, respectively. The maximum monolayer sorption capacities of N-CMCS/PVA/PCL composite and core-shell nanofibers for DOX sorption were 74.31 and 40.74 mg g−1, respectively at optimum pH of 8, equilibrium times of 60 min (composite nanofibers) and 120 min (core-shell nanofibers). The maximum MCF-7 breast cancer cells death was about 57% in the presence of DOX loaded-coaxial nanofibers after 7 days. The obtained results demonstrated the high potential of coaxial nanofibers compared with composite nanofibers for drug delivery of anticancer drugs.

Coaxial Electrospun PLLA Fibers Modified with Water-Soluble Materials for Oligodendrocyte Myelination

Myelin sheaths are essential in maintaining the integrity of axons. Development of the platform for in vitro myelination would be especially useful for demyelinating disease modeling and drug screening. In this study, a fiber scaffold with a core–shell structure was prepared in one step by the coaxial electrospinning method. A high-molecular-weight polymer poly-L-lactic acid (PLLA) was used as the core, while the shell was a natural polymer material such as hyaluronic acid (HA), sodium alginate (SA), or chitosan (CS). The morphology, differential scanning calorimetry (DSC), Fourier transform infrared spectra (FTIR), contact angle, viability assay, and in vitro myelination by oligodendrocytes were characterized. The results showed that such fibers are bead-free and continuous, with an average size from 294 ± 53 to 390 ± 54 nm. The DSC and FTIR curves indicated no changes in the phase state of coaxial brackets. Hyaluronic acid/PLLA coaxial fibers had the minimum contact angle (53.1° ± 0.24°). Myelin sheaths were wrapped around a coaxial electrospun scaffold modified with water-soluble materials after a 14-day incubation. All results suggest that such a scaffold prepared by coaxial electrospinning potentially provides a novel platform for oligodendrocyte myelination.

Production and Characterization of Nanoencapsulated Phase Change Materials (PCMs) and Bicomponent PCM Nanofibers

In this study, n-dodecanol and 1-tetradecanol were nanoencapsulated by poly(methyl metharcylate-co-methacrylic acid) (p(MM-co-MA)) wall using emulsion polymerization method which was defined as one-stage (OS) or two-stage (TS). Nanocapsules were analyzed by Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA). According to the analyses results, typical core-shell structured, spherical shaped, uniform nano-sized particles having high thermal stability and energy storage capacity were fabricated successfully. Enthalpy values of the nanocapsules prepared by TS process were higher and reached up to 171 J/g. It was concluded that thermal degradation stability of the nanocapsules could be improved using TS emulsion polymerization method. Besides, in the study, the nanocapsules were incorporated in polyacrylonitrile nanofibers using co-axial electrospinning method and composite nanofibers having 19 j/g energy storage capacities were produced. The prepared core-sheath structured nanofibers surfaces were rough and coarse but diameter distribution was unimodal.

CoS2-TiO2@C Core-Shell fibers as cathode host material for High-Performance Lithium-Sulfur batteries

Owing to the low cost, high energy density, and high theoretical specific capacity, lithium-sulfur batteries have been deemed as a potential choice for future energy storage devices. However, they also have suffered from several scientific and technical issues including low conductivity, polysulfides migration, and volume changes. In this study, CoS2-TiO2@carbon core–shell fibers were fabricated through combination of coaxial electrospinning and selective vulcanization method. The core–shell fibers are able to efficiently host sulfur, confine polysulfides, and accelerate intermediates conversion. This electrode delivers an initial specific capacity of 1181.1 mAh g−1 and a high capacity of 736.5 mAh g−1 after 300 cycles with high coulombic efficiency over 99.5% (capacity decay of 0.06% per cycle). This strategy of isolating interactant and selective vulcanization provides new ideas for effectively constructing heterostructure materials for lithium-sulfur batteries.

Comparing the wound healing effect of a controlled release wound dressing containing curcumin/ciprofloxacin and simvastatin/ciprofloxacin in a rat model: A preclinical study.

Inflammation and infection are two main factors predisposing a wound to become a chronic one. Degradable wound dressings involving the controlled release of suitable drugs at the ulcer site are one of the solutions to make wounds healing progress smoothly and rapidly. In this research, biodegradable dressings made of polyglycerol sebacate/polycaprolactone (PGS/PCL) containing curcumin/ciprofloxacin (CUR/CIP) and simvastatin/ciprofloxacin (SIM/CIP) were prepared by using the coaxial electrospinning method. Transmission electron microscopy for uniform core/shell structure, swelling ratio, and drug release pattern of the wound dressings were evaluated. At the in vivo study, histometric, histopathologic, and collagen expression study was performed. The PGS/PCL samples containing SIM/CIP showed a burst release pattern of CIP with a delay in the release of SIM; meanwhile, in the samples containing CUR/CIP, both drugs showed a burst release behavior. No cytotoxicity response was observed in the study groups. The in vivo study showed that wound closure was almost completed only in the SIM/CIP group after 14 days. After 14 days, in the wound treated with SIM/CIP dressing, the amount of collagen deposition and angiogenesis was higher than that of the others. These results clearly showed the effect of SIM/CIP on the improvement of the wound healing efficiency in the long term (14 days) and the effect of CUR/CIP on wound contraction in the short term (4day). It seems, therefore, that the use of SIM and CUR simultaneously in a wound dressing could cause a synergistic effect in the wound repair.

Platelet-rich fibrin-loaded PCL/chitosan core-shell fibers scaffold for enhanced osteogenic differentiation of mesenchymal stem cells

Here, we fabricated the platelet-rich fibrin (PRF)-loaded PCL/chitosan (PCL/CS-PRF) core-shell nanofibrous scaffold through a coaxial electrospinning method. Our goal was to evaluate the effect of CS-RPF in the core layer of the nanofibrous on the osteogenic differentiation of human mesenchymal stem cells (HMSCs). The elastic modulus of PCL/CS-PRF core-shell scaffold (44 MPa) was about 1.5-fold of PCL/CS scaffold (25 MPa). The specific surface area of the scaffolds increased from 9.98 m2/g for PCL/CS scaffold to 16.66 m2/g for the PCL/CS-PRF core-shell nanofibrous scaffold. Moreover, the release rate of PRF from PCL/CS-PRF nanofibrous scaffold was measured to be 24.50% after 10 days which showed slow and sustained release of PRF from the nanofibrous. The formation of Ca-P on the surface of scaffold immersed in simulated body fluid solution indicated the suitable osteoconductivity of PCL/CS-PRF core-shell nanofibrous scaffold. Also, the value of ALP activity and calcium deposited on the surface of PCL/CS-PRF core-shell nanofibrous scaffold were 81.97 U/L and 40.33 μg/scaffold, respectively after 14 days, which confirmed the significantly higher amounts of ALP and calcium deposition on the scaffold containing PRF compared to PCL/CS scaffold. Due to higher hydrophilicity and porosity of PCL/CS-PRF core-shell nanofibrous scaffold compared to PCL/CS scaffold, a better bone cell growth on surface of PCL/CS-PRF scaffold was observed. The Alizarin red-positive area was significantly higher on PCL/CS-PRF scaffold compared to PCL/CS scaffold, indicating more calcium deposition and osteogenic differentiation of HMSCs in the presence of PRF. Our findings demonstrate that PCL/CS-PRF core-shell scaffolds can provide a strong construct with improved osteogenic for bone tissue engineering applications.

Electrospun gold nanorods/graphene oxide loaded-core-shell nanofibers for local delivery of paclitaxel against lung cancer during photo-chemotherapy method

The combinations of photothermal therapy (PTT) and chemotherapy (CHT) have attracted increasing attention for cancer therapy. In the present study, paclitaxel as an anticancer drug and graphene oxide/gold nanorods (GO/Au NRs) were simultaneously loaded into the poly (tetramethylene ether) glycol based-polyurethane (PTMG-PU) (core)/chitosan (shell) nanofibers prepared by the coaxial electrospinning method. The potential of the synthesized nanofiber as a pH/temperature dual responsive carrier was investigated for the controlled release of paclitaxel against A549 lung cancer during PTT/CHT combined method. The synthesized core-shell nanofibers were characterized using SEM, TEM and XRD analysis. The drug encapsulation efficiency, drug release and kinetic studies were carried out. The compatibility of the synthesized core-shell nanofibers was also investigated. The cell viability of the synthesized nanofibers treated with A549 lung cancer cells was investigated under alone CHT, alone PTT and PTT/CHT method. The in vivo studies indicated that the PTT/CHT method demonstrated an optimal therapeutic effect on tumor inhibition without change in body weight. The obtained results demonstrated that the synthesized core-shell nanofibers would be used for lung cancer treatment under NIR irradiation in the future.

Electrospun Doxorubicin-loaded PEO/PCL core/sheath nanofibers for chemopreventive action against breast cancer cells

In the present study, polyethylene oxide (PEO)/polycaprolactone (PCL) core/sheath nanofibers were prepared via co-axial electrospinning method. Doxorubicin hydrochloride (DOX) was loaded into the core section of the electrospun nanofibers and their sustained drug release and the cytotoxicity against the MCF-7 breast cancer cell lines were evaluated. The PEO/PCL core/sheath nanofibers were characterized by Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). Moreover, their tensile strength and degradation behavior were investigated. In-vitro release of DOX from the nanofibers in phosphate buffer solution (PBS) at pH = 7.4 and its release kinetics were also evaluated. Finally, the cytotoxicity of the pristine and DOX loaded nanofibers was investigated. The degradation rate of the fiber mats was slow, indicating that the drug release was controlled by diffusion process. Nearly 20–30% of the drug was released at first day and till 28 days up to 60% of the drug was released. Their cell viability toward the MCF-7 breast cancer cells was examined via MTT assay at 1, 3, and 8 day. They showed no toxicity effect. Also, our results revealed high activity of the DOX-loaded core/sheath nanofibers against the MCF-7 breast cancer cells.

Comparative Analysis of Electrospun Uniaxial and Coaxial Nanofibers Properties

Coaxial electrospinning, which is a modified electrospinning technique involving an arrangement of multiple solution feed systems, enable the production of multilayered nanofibers. In this study, multilayered nanofibers of polyamide 6 (core) / polycaprolactone (shell) containing silver nanoparticles in the core were produced by coaxial electrospinning method. UV-Visible spectra showed that the size of nanoparticles were about 10 nm and the content of nanoparticles were observed to be proportional to the precursor content added to the solvent. The obtained multilayered nanofibers were characterized in terms of morphology, chemical structure, and silver release properties. The multilayered nanofiber structure was confirmed by the selective dissolution and removal of shell layer. The increase in the PCL content of the multilayered nanofibers with the increase in the flow rate of the shell solution was confirmed by FTIR. The silver release profiles of the nanofibers were observed to be dependent on the nanofiber configuration, and silver content. Shell thickness was also an important parameter affecting the silver release properties for multilayered nanofibers.