Coaxial Electrospinning Research Articles

Synthesis of Smart Nanofiber Coatings with Autonomous Self-Warning and Self-Healing Functions.

Organic protective coatings are widely used to protect metal structures from corrosion but they are vulnerable to undetectable damage. Without timely detection and repair, it could lead to severe consequences. How to warn and heal damaged areas simultaneously and automatically has become a challenging problem. Herein, we report an intelligent protective coating with self-warning and self-healing functions. This strategy was achieved by embedding bifunctional nanofibers containing 1,10-phenanthroline (Phen) in organic coatings. The nanofibers with Phen as a core and a poly(vinyl alcohol) (PVA)─chitosan (CS) blend solution as a shell were synthesized by coaxial electrospinning. The PVA/CS@Phen nanofiber-embedded coating displayed self-healing and high contrast indication function of the damaged area on coatings. Prominent red could warn microdamage and macrosurface damage, which occurred rapidly and healed permanently. The intelligent coating exhibited high healing performance under artificial injury with self-warning characteristics, and the cure rate was about 98.4% without external intervention. In the healing process, free amino groups of CS in the shell of nanofibers enhanced the sustained release of Phen. This convenient, economical, and efficient strategy with cooperative functions of self-warning and self-healing delivers an effective solution for prolonging the service life of protective coatings. This multifunctional coating exhibits excellent potential in the field of marine engineering applications.

Dynamic Interference Colors in Electrospun Microfibrous Mats

AbstractThe design of soft materials that change their optical properties in response to a variety of external stimuli is one step toward mimicking the dynamic color changing systems that are observed in nature. A simple, multiresponsive system is presented where the colors of core/sheath microfibers and microfibrous mats can be tuned by confinement (i.e., fiber diameter), temperature, and UV–vis irradiation. Microfibers are fabricated using coaxial electrospinning with a nematic liquid crystal core and a polymer sheath. This results in soft, flexible mats of material that display uniform color when viewed between crossed‐polarizers both under a microscope and by the naked eye. The observed interference color is dictated by the inner fiber diameter and the birefringence of the liquid crystal core. While the fiber diameter is set during mat fabrication, continuous in situ color change by tuning the birefringence of the liquid crystal is demonstrated using temperature or photochemical control of azobenzene‐based surfactants embedded in the polymer sheath. The expected colors are calculated and easy‐to‐use color charts are generated to accurately predict fiber behavior.

Controlled release of curcumin from coaxial electrospun nanofiber mats

AbstractIn this study, a controlled drug delivery system (DDS) was developed by coaxial electrospinning. Fabricate a controlled DDS using electrospun nanofibers formed with a single concentric nozzle is challenging because of the rapid initial release rate. Therefore, in this study, electrospinning was conducted using dual or triple concentric nozzles to fabricate controlled DDSs. Polycaprolactone and poly(ethylene oxide) were used as the shell and core polymeric materials, respectively, and curcumin was used as the model drug. The spinning feed rate was controlled, and dual and triple concentric nozzles were used to manipulate the shell thickness of the nanofiber. Increasing the shell thickness significantly lowered the release rate. The triple concentric nozzle was effective to obtain a slower release rate than dual concentric nozzle. The coaxial electrospun nanofibers were characterized using optical microscopy and infrared spectroscopy.

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.

Fabrication and characterization of gas-assisted core-shell hydrogel nanofibers as a drug release system with antibacterial activity

In this research, fabrication and characterization of core-shell hydrogel nanofibrous mats containing Polylactic acid/Sage extract in the core and Polyvinylpyrrolidone/Polyvinyl alcohol in the shell, utilizing a novel gas-assisted coaxial electrospinning technique was investigated. The use of an extra gas blowing system allowed to increase core and shell flow rates remarkably and contributed to the higher production of nanofibers in a very short time. To construct the core-shell structure, first, the core solution containing Polylactic acid 8 wt% and Sage extract 10 wt% was prepared. Then the shell solution including Polyvinylpyrrolidone 20 wt% and Polyvinyl alcohol 9 wt% was made and citric acid 2.5 wt% was added as the crosslinking agent. The core and shell solutions were loaded separately in a coaxial spinneret and the gas-assisted coaxial electrospinning was conducted. In the end, the electrospun mats were cured in an oven to obtain core-shell hydrogel nanofibers. The kinetics of the swelling, the release of Sage extract, and the effects of various amounts of crosslinker on the swelling and release process were investigated for core-shell hydrogel nanofibers and then compared to that of the single-core and shell systems. Moreover, the antibacterial assay was performed on the fabricated core-shell hydrogel nanofibers to assess the antimicrobial properties of the electrospun mats. Further evaluations were performed through SEM, TEM, FTIR, DSC, and TGA analyses to determine the morphology and structure of individual systems. The electrospun mats can find excessive applications in biomedical fields as antibacterial dressings for superficial wounds.

An innovative and facile strategy to construct GdF3:Eu3+@Void@SiO2 nanowire-in-nanotube structured nanofibers with photoluminescence-magnetism Bi-functionality

An innovative and facile approach has been designed to construct non-shattering GdF3:Eu3+@void@SiO2 nanowire-in-nanotube structured nanofibers (NSN) via a new technique combining electrospinning and fluorination strategy efficiently for the first time. The average diameters of the outer tubes and inner wires of GdF3:Eu3+@void@SiO2 NSN are 403 ± 36 nm and 157 ± 20 nm, respectively. GdF3:Eu3+@void@SiO2 NSN simultaneously possess excellent luminescent and paramagnetic properties, which are suitable for many applications such as light-emitting devices, lasers and planar waveguides, biomedical therapy and drug delivery. Nanowire-in-nanotube structured nanofibers possess large length-diameter ratio, their peculiar void-space structures make them have promising applications in biotherapy, energy storage, sensors, catalysts, etc. A series of conditional experiments including GdF3:Eu3+/SiO2 composite nanofibers, GdF3:Eu3+ nanofibers, and GdF3:Eu3+@SiO2 nanomaterials with different morphologies have been performed to validate the success of the synthesis technology. The fabrication technique has some advantages over other methods, for example, simple and convenient, high-efficient, economical, and without introducing organics. More importantly, the approach can overcome the drawback of synthesizing complexity used by template-assisted means and coaxial electrospinning process, etc. This strategy is a universal technology for the construction of nanowire-in-nanotube structured multifunctional nanomaterials, and extends the application fields of electrospinning technology.

Core-Sheath Electrospun Nanofibers Based on Chitosan and Cyclodextrin Polymer for the Prolonged Release of Triclosan.

This work focuses on the manufacture of core-sheath nanofibers (NFs) based on chitosan (CHT) as sheath and cyclodextrin polymer (PCD) as core and loaded with triclosan (TCL). In parallel, monolithic NFs consisting of blended CHT-PCD and TCL were prepared. Nanofibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier Transform Infrared spectroscopy (FTIR). SEM displayed the morphology of NFs and the structure of the nanowebs, while TEM evidenced the core-sheath structure of NFs prepared by coaxial electrospinning. The core diameters and sheath thicknesses were found dependent on respective flow rates of both precursor solutions. Nanofibers stability and TCL release in aqueous medium were studied and correlated with the antibacterial activity against Staphylococcus aureus and Escherichia coli. Results showed that the release profiles of TCL and therefore the antibacterial activity were directly related to the type of nanofibers. In the case of monolithic nanofibers, the NFs matrix was composed of polyelectrolyte complex (PEC formed between CHT and PCD) and resulted in a prolonged release of TCL and a sustained antibacterial effect. In the case of core-sheath NFs, the PEC was formed only at the core-sheath interface, leading to less stable NFs and therefore to a faster release of TCL, and to a less extended antibacterial activity compared to monolithic ones.

Flexible NiCo2S4-hollow carbon nanofibers electrocatalytic membrane as an advanced interlayer for lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries have been recognized to be one of the most promising devices for next-generation energy storage devices. However, the severe lithium polysulfides (LiPSs) shuttle effect and torpid redox kinetics hinder their practical application. To solve these issues, a flexible NiCo2S4-hollow carbon nanofibers (NiCo2S4@HCNF) electrocatalytic membrane for Li-S batteries interlayer is fabricated by combining coaxial electrospinning and hydrothermal methods. On the one hand, the conductive framework of HCNF with hollow structure can buffer more electrolytes, which provides fast electron transport pathways and shortens the diffusion distance of ions. On the other hand, the dense NiCo2S4 nanowires uniformly grow on the surface of the HCNF, which can adsorb and catalyze LiPSs conversion. Due to the structural advantage of the NiCo2S4@HCNF, the Li-S batteries exhibit excellent cycling stability (only 0.06% decay per cycle in 500 cycles at 1 C) and high specific capacity (607.6 mA h g−1 at 3 C). This research illustrates that the NiCo2S4@HCNF composite has extensive application prospects in high-performance Li-S batteries.

Design and Fabrication of Nanofibrous Dura Mater with Antifibrosis and Neuroprotection Effects on SH-SY5Y Cells.

The development and treatment of some diseases, such as large-area cerebral infarction, cerebral hemorrhage, brain tumor, and craniocerebral trauma, which may involve the injury of the dura mater, elicit the need to repair this membrane by dural grafts. However, common dural grafts tend to result in dural adhesions and scar tissue and have no further neuroprotective effects. In order to reduce or avoid the complications of dural repair, we used PLGA, tetramethylpyrazine, and chitosan as raw materials to prepare a nanofibrous dura mater (NDM) with excellent biocompatibility and adequate mechanical characteristics, which can play a neuroprotective role and have an antifibrotic effect. We fabricated PLGA NDM by electrospinning, and then chitosan was grafted on the nanofibrous dura mater by the EDC-NHS cross-linking method to obtain PLGA/CS NDM. Then, we also prepared PLGA/TMP/CS NDM by coaxial electrospinning. Our study shows that the PLGA/TMP/CS NDM can inhibit the excessive proliferation of fibroblasts, as well as provide a sustained protective effect on the SH-SY5Y cells treated with oxygen–glucose deprivation/reperfusion (OGD/R). In conclusion, our study may provide a new alternative to dural grafts in undesirable cases of dural injuries.

A careob-like nanofibers with a sustained drug release profile for promoting skin wound repair and inhibiting hypertrophic scar

Excessive or disordered wound repair results in abnormal hyperplasia of scars, which intensifies the complexity and difficulty of treatment. The reported wound repair dressings, which only possess single function, can promote wound healing diminutively or treat hypertrophic scars solely. Wound healing and scar formation are the two affiliated successive stages of the wound repair process. Therefore, it is crux for the promotion of wound healing and the inhibition of scar hyperplasia synergistically. In this study, we have synthesized a 5-fluorouracil (5-Fu)-loaded dendritic mesoporous bioglass nanoparticles (dMBG) coaxial electrospun in polyethylene oxide (PEO)-poly(ether-ester-urethane)urea (PEEUU) careob-like core-shell composite nanofibers (((F@B)/P)@PU) through synergistic effect of hydrogen bonding networking and physical adsorption, and coaxial electrospinning . The 5-Fu-loaded dBMG (5-Fu@dMBG) with an optimized 5-Fu loading efficiency of 23% were shown to be successfully contained in PEO matrix, and the formed ((F@B)/P)@PU exhibited a uniform and smooth morphology, appropriate surface wettability , high protein adsorption rate, as well as matched degradation rate and mechanical properties with autologous skin tissue. Importantly, the loaded 5-Fu within ((F@B)/P)@PU exhibiteda sustained-release profile and anti-adhesion/anti-proliferation active to inhibit the growth of Hela cells , which is a model cell with the property of rapid proliferation. In addition, the wound model of rat back and H&E staining, Masson trichrome staining, CD31, CD68 and collagen I immunofluorescence staining were performed for evaluating therapeutic efficiency of ((F@B)/P)@PU. All the results revealed the better wound treatment effect of 5-Fu-loaded multistructure nanofibers for the repair of scar skin tissue defects, indicating great potential for wounds healing clinically.

Preparation and biological properties of ZnO/hydroxyapatite/chitosan-polyethylene oxide@gelatin biomimetic composite scaffolds for bone tissue engineering

To imitate the composition of natural bone and further improve the biological property of the materials, ZnO/hydroxyapatite/chitosan-polyethylene oxide@gelatin (ZnO/HAP/CS-PEO@GEL) composite scaffolds were developed. The core-shell structured chitosan-polyethylene oxide@gelatin (CS-PEO@GEL) nanofibers which could form the intramolecular hydrogen bond and achieve an Arg-Gly-Asp (RGD) polymer were first prepared by coaxial electrospinning to mimic the extracellular matrix. To further enhance biological activity, hydroxyapatite (HAP) was grown on the surface of the CS-PEO@GEL nanofibers using chemical deposition and ZnO particles were then evenly distributed on the surface of the above composite materials using RF magnetron sputtering. The SEM results showed that chemical deposition and magnetron sputtering did not destroy the three-dimensional architecture of materials, which was beneficial to cell growth. The cell compatibility and proliferation of MG-63 cells on ZnO/HAP/CS-PEO@GEL composite scaffolds were superior to those on CS-PEO@GEL and HAP/CS-PEO@GEL composite scaffolds. An appropriate amount of ZnO sputtering could promote the adhesion of cells on the composite nanofibers. The structure of bone tissue could be better simulated both in composition and in the microenvironment, which provided a suitable environment for cell growth and promoted the proliferation of MG-63 cells. The biomimetic ZnO/HAP/CS-PEO@GEL composite scaffolds were promising materials for bone tissue engineering.

Hollow ZnO@SnO2–Pt Core–Shell Nanofibers for Ethanol Sensing

In this study, ZnO@SnO2–Pt core–shell nanofibers with a hollow structure have been prepared by coaxial electrospinning and heat treatment. The core–shell and hollow structures of nanofibers were confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The Brunauer–Emmett–Teller (BET) specific surface area test shows that the specific surface area of ZnO@SnO2–Pt core–shell nanofibers is larger than those of ZnO@SnO2 core–shell nanofibers and SnO2 nanofibers. The gas-sensing test result shows that the response to 100 ppm ethanol gas is 132.04 and the response time is 5 s at 200 °C for ZnO@SnO2–Pt core–shell nanofibers with 0.3 wt % Pt. Compared with those of ZnO@SnO2 core–shell nanofibers without Pt and pure SnO2 nanofibers, the optimum working temperature of ZnO@SnO2–Pt core–shell nanofibers is reduced by 125 °C and the maximum response is increased by 70.9 and 367.7%. Furthermore, the gas-sensing mechanism is discussed in detail.

Highly-hydrophobic nanofiber mat for efficient colonic delivery of lactoferrin: Preparation, characterization and release mechanism

Lactoferrin (Lf) is a bioactive protein with varied biological effects. To improve its anti-digestive stability in oral administration, a novel nanocarrier with high hydrophobicity for colonic delivery of Lf was creatively developed by modified coaxial electrospinning. First, a suitable biocompatible solvent, acetic acid, was screened as the mono-solvent for ES100 electrospinning, creating highly-hydrophobic ES100 nanofiber mat (contact angle = 133.8o). Then, Lf-loaded W/O emulsion was prepared as the core fluid to ensure the successful coaxial electrospinning and generate Lf encapsulated core/shell nanofiber mat (ES@Lf). Lf was demonstrated maintaining structural integrity and anti-colon cancer activity during encapsulation and oral delivery. In vitro assay indicated 92.3% Lf was sustainably released in colon, and its release followed a complex mechanism in which the erosion was dominant. Instead of pH-dependent erosion, the synergistic action through gut microbiota adhesion and their metabolites, especially short-chain fatty acids, was illustrated for disintegration of ES@Lf nanofiber for the first time.

Significant Electromechanical Characteristic Enhancement of Coaxial Electrospinning Core-Shell Fibers.

Electrospinning is a low-cost and straightforward method for producing various types of polymers in micro/nanofiber form. Among the various types of polymers, electrospun piezoelectric polymers have many potential applications. In this study, a new type of functional microfiber composed of poly(γ-benzyl-α,L-glutamate) (PBLG) and poly(vinylidene fluoride) (PVDF) with significantly enhanced electromechanical properties has been reported. Recently reported electrospun PBLG fibers exhibit polarity along the axial direction, while electrospun PVDF fibers have the highest net dipole moment in the transverse direction. Hence, a combination of PBLG and PVDF as a core–shell structure has been investigated in the present work. On polarization under a high voltage, enhancement in the net dipole moment in each material and the intramolecular conformation was observed. The piezoelectric coefficient of the electrospun PBLG/PVDF core–shell fibers was measured to be up to 68 pC N−1 (d33), and the voltage generation under longitudinal extension was 400 mVpp (peak-to-peak) at a frequency of 60 Hz, which is better than that of the electrospun homopolymer fibers. Such new types of functional materials can be used in various applications, such as sensors, actuators, smart materials, implantable biosensors, biomedical engineering devices, and energy harvesting devices.

A methylprednisolone-loaded and core-shell nanofiber-covered stent-graft to prevent inflammation and reduce degradation in aortic dissection

BackgroundStent-graft-induced inflammation is an independent risk factor for adverse aortic remodeling in aortic dissection. In this context, we asked that whether a methylprednisolone-loaded stent-graft could reduce inflammation and degradation.MethodsFirst, a coaxial electrospinning technique was used to create a core-shell film with methylprednisolone encapsulated in the inner of poly (L-lactide-co-caprolactone) nanofibers for controllable drug release. Second, an in vitro study was conducted to evaluate the biocompatibility of the nanofiber meshes. Third, the porcine aortic dissection model was developed to investigate the therapeutic effects of the methylprednisolone-loaded stent-graft.ResultsThe results demonstrated that the nanofiber-coated film with a methylprednisolone-poly-caprolactone core layer and a poly (L-lactide-co-caprolactone) shell layer could effectively sustain drug release in vitro. In vivo study showed that the methylprednisolone-loaded stent-graft could reduce degradtion of aortic dissection by regulating inflammation.ConclusionsOverall, the controllable drug release by coaxial nanofiber is a promising approach to alleviate aortic inflammation and promote aortic remodeling after stent-graft implantation.

High-efficiency production of core-sheath nanofiber membrane via co-axial electro-centrifugal spinning for controlled drug release

Core-sheath nanofibers are a premium material to be used in the field of controlled drug release, however, a mass-production of this kind of fibers by current spinning methods is until now limited due to the issues of nozzle clogging and high costs. In this context, a brand-new technology, named co-axial electro-centrifugal spinning (ECS), which combines the technologies of co-axial electrospinning and centrifugal spinning, was proposed to fabricate core-sheath nanofibers in large amounts. Compared with traditional co-axial electrospinning, the in-house-built co-axial ECS well addressed the nozzle cleaning problem. By means of the co-axial ECS, different kinds of core-sheath nanofibers were successfully produced. Being already extensively-applied biodegradable polymers, poly(vinyl alcohol) (PVA) and poly(l-lactic acid) (PLLA) were chosen to manufacture PVA/PLLA core/sheath nanofibers with different core-to-sheath ratios in ultra-high production rate. Also, Paclitaxel drug was loaded in the PVA core component and its release was efficiently controlled thanks to the thickness and crystallinity of the PLA sheath. The in vitro drug release mechanism studied here suggested that the drug can still release out without the existence of porous microchannels. This accessible and low-cost technology may definitely offer a new insight into the fabrication of core-sheath nanofibers, allowing more researchers to tailor functional fabrics.

Preparation of Linalool/Polycaprolactone Coaxial Electrospinning Film and Application in Preserving Salmon Slices.

A linalool/polycaprolactone (LL/PCL) antibacterial film was prepared by using a coaxial electrospinning process, and its physical and chemical properties were characterized. The antibacterial film was formed into an active antibacterial gasket, and its effect on salmon preservation was analyzed. The results show that the LL/PCL nanofiber membrane had a well-developed microstructure, and the fiber surface was smooth and uniform. The diameter of the fibers in the PCL membrane without the core material (linalool) was 113.92 ± 23.74 nm. In contrast, the diameter of the coaxial nanofiber membrane with linalool increased, and the diameter of the LL/PCL membranes with 20% and 40% linalool was 220.62 ± 44.01 and 232.22 ± 56.27 nm, respectively. The hydrophobicity and water vapor permeability were enhanced, whereas the tensile strength and elongation at break decreased slightly, while the thermal stability did not differ significantly with the incorporation of linalool. Analysis of the sustained release of linalool showed that the LL/PCL coaxial fiber membranes could release linalool into the reaction system for a long time. The LL/PCL nanofiber film was used to create an antibacterial active gasket for salmon preservation experiments. Sensory evaluation and analyses of the total bacterial count, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), pH, texture (hardness, elasticity, chewiness, and viscoelasticity), water distribution change, and aroma using an electronic nose were used to determine the quality of salmon. It was found that food-grade tinfoil and the PCL gasket had no significant effect on the freshness of salmon, while the active antibacterial gasket samples containing linalool could decrease the rate of decay salmon and effectively prolong the shelf-life of salmon by releasing linalool.

Development and Characterization of Furfuryl-Gelatin Electrospun Scaffolds for Cardiac Tissue Engineering.

In this study, three types of electrospun scaffolds, including furfuryl-gelatin (f-gelatin) alone, f-gelatin with polycaprolactone (PCL) in a 1:1 ratio, and coaxial scaffolds with PCL (core) and f-gelatin (sheath), were developed for tissue engineering applications. Scaffolds were developed through single nozzle electrospinning and coaxial electrospinning, respectively, to serve as scaffolds for cardiac tissue engineering. Uniform fibrous structures were revealed in the scaffolds with significantly varying average fiber diameters of 760 ± 80 nm (f-gelatin), 420 ± 110 nm [f-gelatin and PCL (1:1)], and 810 ± 60 nm (coaxial f-gelatin > PCL) via scanning electron microscopy. The distinction between the core and the sheath of the fibers of the coaxial f-gelatin > PCL electrospun fibrous scaffolds was revealed by transmission electron microscopy. Thermal analysis and Fourier transformed infrared (FTIR) spectroscopy revealed no interactions between the polymers in the blended electrospun scaffolds. The varied blending methods led to significant differences in the elastic moduli of the electrospun scaffolds with the coaxial f-gelatin > PCL revealing the highest elastic modulus of all scaffolds (164 ± 3.85 kPa). All scaffolds exhibited excellent biocompatibility by supporting the adhesion and proliferation of human AC16 cardiomyocytes cells. The biocompatibility of the coaxial f-gelatin > PCL scaffolds with superior elastic modulus was assessed further through adhesion and functionality of human-induced pluripotent stem cell (hiPSC)-derived cardiomyocytes, thereby demonstrating the potential of the coaxially spun scaffolds as an ideal platform for developing cardiac tissue-on-a-chip models. Our results demonstrate a facile approach to produce visible light cross-linkable, hybrid, biodegradable nanofibrous scaffold biomaterials, which can serve as platforms for cardiac tissue engineered models.

Electrospun Cellulose-Acetate/Chitosan Fibers for Humic-Acid Removal: Improved Efficiency and Robustness with a Core-Sheath Design.

Recycling biomass waste into functional materials has attracted much attention, and a rational structural design can make more effective use of each component. In our previous work, the fabrication of electrospun cellulose-acetate (CA)/chitosan (CS) adsorbents for humic-acid (HA) removal guided by the intermolecular interaction mechanism was demonstrated. Herein, a core-sheath structure was designed via one-step co-axial electrospinning, where a mixture of CS and CA was employed as the sheath layer to efficiently adsorb HA, and cellulose nanocrystals (CNCs) derived from waste cotton fabrics were incorporated into the CA core as load-bearing components. Compared to the non-layered electrospun CS/CA fibers, all the CS/CA–CNC fibers with a core-sheath structure exhibited smaller diameters, greater homogeneity, and significantly improved mechanical strength. Meanwhile, their maximum adsorption capacities towards HA had no significant differences. Even after the complete hydrolysis of CA into cellulose, the electrospun fibers maintained the fibrous structures and showed a higher tensile strength while exhibiting an acceptable adsorption capacity towards HA. Therefore, this work demonstrates the importance of rational design in the efficient preparation of functional materials and the feasibility of using electrospun core-sheath fibers derived from biomass wastes for the removal of water contaminants.

Functional Mesostructured Electrospun Polymer Nonwovens with Supramolecular Nanofibers.

Functional, hierarchically mesostructured nonwovens are of fundamental importance because complex fiber morphologies increase the active surface area and functionality allowing for the effective immobilization of metal nanoparticles. Such complex functional fiber morphologies clearly widen the property profile and enable the preparation of more efficient and selective filter media. Here, the realization of hierarchically mesostructured nonwovens with barbed wire-like morphology is demonstrated by combining electrospun polystyrene fibers, decorated with patchy worm-like micelles, with solution-processed supramolecular short fibers composed of 1,3,5-benzenetricarboxamides with peripheral N,N-diisopropylaminoethyl substituents. The worm-like micelles with a patchy microphase-separated corona are prepared by crystallization-driven self-assembly of a polyethylene based triblock terpolymer and deposited on top of the polystyrene fibers by coaxial electrospinning. The micelles are designed in a way that their patches promote the directed self-assembly of the 1,3,5-benzenetricarboxamide and the fixation of the supramolecular nanofibers on the supporting polystyrene fibers. Functionality of the mesostructured nonwoven is provided by the peripheral N,N-diisopropylaminoethyl substituents of the 1,3,5-benzenetricarboxamide and proven by the effective immobilization of individual palladium nanoparticles on the supramolecular nanofibers. The preparation of hierarchically mesostructured nonwovens and their shown functionality demonstrate that such systems are attractive candidates to be used for example in filtration, selective separation and heterogenous catalysis.