Thin PVA/nickel acetate composite fibres were prepared by using sol-gel processing and electrospinning technique. After calcination of the above precursor fibres, NiO nanofibres with a diameter of 50-150 nm could be ...Thin PVA/nickel acetate composite fibres were prepared by using sol-gel processing and electrospinning technique. After calcination of the above precursor fibres, NiO nanofibres with a diameter of 50-150 nm could be successfully obtained. The fibres were characterized by SEM, FT-IR, WAXD, respectively.展开更多
Poly(vinylpyrrolidone)/tetrabutyl titanate (PVP/ [CH3(CH2)3O]4Ti) composite nanofibres are prepared by electrospinning. After calcining parts of composite nanofibres in air at 700 ~℃, petal-like TiO2 nanostruct...Poly(vinylpyrrolidone)/tetrabutyl titanate (PVP/ [CH3(CH2)3O]4Ti) composite nanofibres are prepared by electrospinning. After calcining parts of composite nanofibres in air at 700 ~℃, petal-like TiO2 nanostructures are obtained. The characterizations of composite nanofibres and TiO2 nanostructures are carried out by a scanning electron microscope, an x-ray diffractometer, and an infrared spectrometer. Electrospun nanofibres are pressed into pellets under different pressures in order to explore their dielectric properties. It is found that the dielectric constants decrease with frequency increasing. The dielectric constant of the composite nanofibre pellet increases whereas its dielectric loss tangent decreases due to the doped titanium ions compared with those of pure PVP nanofibre pellets. In addition, it is observed that the dielectric constant of the composite nanofibre pellet decreases with the increase of the pressure applied in pelletization.展开更多
NiZn ferrite/polyvinylpyrrolidone composite fibres were prepared by sol,el assisted electrospinning. Ni0.5Zn0.5Fe2O4 nanofibres with a pure cubic spinel structure were obtained subsequently by calcination of the compo...NiZn ferrite/polyvinylpyrrolidone composite fibres were prepared by sol,el assisted electrospinning. Ni0.5Zn0.5Fe2O4 nanofibres with a pure cubic spinel structure were obtained subsequently by calcination of the composite fibres at high temperatures. This paper investigates the thermal decomposition process, structures and morphologies of the electrospun composite fibres and the calcined Ni0.5Zn0.5Fe2O4 nanofibres at different temperatures by thermo-gravimetric and differential thermal analysis, x-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The magnetic behaviour of the resultant nanofibres was studied by a vibrating sample magnetometer. It is found that the grain sizes of the nanofibres increase significantly and the nanofibre morphology graduMly transforms from a porous structure to a necklace-like nanostructure with the increase of calcination tempera-ture. The Ni0.5Zn0.5Fe2O4 nanofibres obtained at 1000℃ for 2h are characterized by a necklace-like morphology and diameters of 100-200nm. The saturation magnetization of the random Ni0.5Zn0.5Fe2O4 nanofibres increases from 46.5 to 90.2 emu/g when the calcination temperature increases from 450 to 1000℃. The coercivity reaches a maximum value of 11.0 kA/m at a calcination temperature of 600℃. Due to the shape anisotropy, the aligned Ni0.5Zn0.5Fe2O4 nanofibres exhibit an obvious magnetic anisotropy and the ease magnetizing direction is parallel to the nanofibre axis.展开更多
Ca and Mn co-doped BiFeO3 ultrafine nanofibres were prepared with the purpose of improving magnetic and photocatalytic performances of the one-dimensional multiferroic material. Impurity phase introduced by both Bi fl...Ca and Mn co-doped BiFeO3 ultrafine nanofibres were prepared with the purpose of improving magnetic and photocatalytic performances of the one-dimensional multiferroic material. Impurity phase introduced by both Bi fluctuation and Mn substitution can be suppressed by Ca doping and a space group transition from R3c to C222 can also be triggered by Bi-site doping. With co-substitution of Mn into iron site, the Ca0.15Bi0.85Mn0.05Fe0.95O3 nanofibres presented a larger saturation magnetization than the singly Ca doping samples, possibly due to the increased double exchange interation of Fe3+-O-Fe2+, strengthened by Ca and Mn. Photocatalytic degradation test witnessed a similar drop-and-rise performance with the magnetism.展开更多
Nanofiber membranes(NFMs) have become attractive candidates for next-generation flexible transparent materials due to their exceptional flexibility and breathability. However, improving the transmittance of NFMs is a ...Nanofiber membranes(NFMs) have become attractive candidates for next-generation flexible transparent materials due to their exceptional flexibility and breathability. However, improving the transmittance of NFMs is a great challenge due to the enormous reflection and incredibly poor transmission generated by the nanofiber-air interface. In this research, we report a general strategy for the preparation of flexible temperature-responsive transparent(TRT) membranes,which achieves a rapid transformation of NFMs from opaque to highly transparent under a narrow temperature window. In this process, the phase change material eicosane is coated on the surface of the polyurethane nanofibers by electrospray technology. When the temperature rises to 37 ℃, eicosane rapidly completes the phase transition and establishes the light transmission path between the nanofibers, preventing light loss from reflection at the nanofiber-air interface. The resulting TRT membrane exhibits high transmittance(> 90%), and fast response(5 s). This study achieves the first TRT transition of NFMs, offering a general strategy for building highly transparent nanofiber materials, shaping the future of next-generation intelligent temperature monitoring, anti-counterfeiting measures, and other high-performance devices.展开更多
Current therapeutic approaches for volumetric muscle loss(VML)face challenges due to limited graft availability and insufficient bioactivities.To overcome these limitations,tissue-engineered scaffolds have emerged as ...Current therapeutic approaches for volumetric muscle loss(VML)face challenges due to limited graft availability and insufficient bioactivities.To overcome these limitations,tissue-engineered scaffolds have emerged as a promising alternative.In this study,we developed aligned ternary nanofibrous matrices comprised of poly(lactide-co-ε-caprolactone)integrated with collagen and Ti_(3)C_(2)T_(x)MXene nanoparticles(NPs)(PCM matrices),and explored their myogenic potential for skeletal muscle tissue regeneration.The PCM matrices demonstrated favorable physicochemical properties,including structural uniformity,alignment,microporosity,and hydrophilicity.In vitro assays revealed that the PCM matrices promoted cellular behaviors and myogenic differentiation of C2C12 myoblasts.Moreover,in vivo experiments demonstrated enhanced muscle remodeling and recovery in mice treated with PCM matrices following VML injury.Mechanistic insights from next-generation sequencing revealed that MXene NPs facilitated protein and ion availability within PCM matrices,leading to elevated intracellular Ca^(2+)levels in myoblasts through the activation of inducible nitric oxide synthase(i NOS)and serum/glucocorticoid regulated kinase 1(SGK1),ultimately promoting myogenic differentiation via the m TOR-AKT pathway.Additionally,upregulated i NOS and increased NO–contributed to myoblast proliferation and fiber fusion,thereby facilitating overall myoblast maturation.These findings underscore the potential of MXene NPs loaded within highly aligned matrices as therapeutic agents to promote skeletal muscle tissue recovery.展开更多
Three-dimensional(3D) printing provides a promising way to fabricate biodegradable scaffolds with designer architectures for the regeneration of various tissues.However,the existing3D-printed scaffolds commonly suffer...Three-dimensional(3D) printing provides a promising way to fabricate biodegradable scaffolds with designer architectures for the regeneration of various tissues.However,the existing3D-printed scaffolds commonly suffer from weak cell-scaffold interactions and insufficient cell organizations due to the limited resolution of the 3D-printed features.Here,composite scaffolds with mechanically-robust frameworks and aligned nanofibrous architectures are presented and hybrid manufactured by combining techniques of 3D printing,electrospinning,and unidirectional freeze-casting.It was found that the composite scaffolds provided volume-stable environments and enabled directed cellular infiltration for tissue regeneration.In particular,the nanofibrous architectures with aligned micropores served as artificial extracellular matrix materials and improved the attachment,proliferation,and infiltration of cells.The proposed scaffolds can also support the adipogenic maturation of adipose-derived stem cells(ADSCs)in vitro.Moreover,the composite scaffolds were found to guide directed tissue infiltration and promote nearby neovascularization when implanted into a subcutaneous model of rats,and the addition of ADSCs further enhanced their adipogenic potential.The presented hybrid manufacturing strategy might provide a promising way to produce additional topological cues within 3D-printed scaffolds for better tissue regeneration.展开更多
Burn injury is a serious public health problem and scientists are continuously aiming to develop promising biomimetic dressings for effective burn wound management.In this study,a greater efficacy in burn wound healin...Burn injury is a serious public health problem and scientists are continuously aiming to develop promising biomimetic dressings for effective burn wound management.In this study,a greater efficacy in burn wound healing and the associated mechanisms ofα-lactalbumin(ALA)based electrospun nanofibrous scaffolds(ENs)as compared to other regenerative protein scaffolds were established.Bovine serum albumin(BSA),collagen type I(COL),lysozyme(LZM)and ALA were separately blended with poly(ε-caprolactone)(PCL)to fabricate four different composite ENs(LZM/PCL,BSA/PCL,COL/PCL and ALA/PCL ENs).The hydrophilic composite scaffolds exhibited an enhancedwettability and variablemechanical properties.The ALA/PCL ENs demonstrated higher levels of fibroblast proliferation and adhesion than the other composite ENs.As compared to PCL ENs and other composite scaffolds,the ALA/PCL ENs also promoted a better maturity of the regenerative skin tissues and showed a comparable wound healing effect to Collagen sponge^(■)on third-degree burn model.The enhanced wound healing activity of ALA/PCL ENs compared to other ENs could be attributed to their ability to promote serotonin production at wound sites.Collectively,this investigation demonstrated that ALA is a unique protein with a greater potential for burn wound healing as compared to other regenerative proteins when loaded in the nanofibrous scaffolds.展开更多
Due to some intrinsic functional behavior of alginate, many potential applications in the healthcare industry especially in wound care sector are observed. Many researches have been carried out to develop potential bi...Due to some intrinsic functional behavior of alginate, many potential applications in the healthcare industry especially in wound care sector are observed. Many researches have been carried out to develop potential biomedical biocompatible products in different forms from alginate fibres. Alginate nanofibres were prepared from sodium alginate polymer with the presence of poly-(ethylene oxide) (PEO), a small amount of Triton ×100 surfactant. A homogeneous spinning solution was prepared for producing Na-alginate/PEO nanofibers in electrospinning device. Nanofibres were produced by electrospinning from 70:30 and 80:20 Na-alginate/PEO of 4% solution. After a series of trials, the electrospinning parameters were optimized at 16 cm working distance, 0.4 mL/h flow rate and 10.5 kV applied voltage. The results show that the 4 wt% of 70:30 Na-alginate/PEO solution with 0.5 wt% Triton × 100 surfactant yielded smooth and stable electrospinning. The surface morphology of the fibres was investigated using Scanning Electron Microscope (SEM) and found the uniform fibres with an average diameter of 124 nm containing few thick or spindle-like fibres. FTIR investigation identified the chemical structure and molecular changes that occurred in the fibers.展开更多
High-repetition-rate femtosecond lasers enable the precise production of nanofoam from a wide range of materials. Here, the laser-based fabrication of nanofoam from silicon, borosilicate glass, sodalime glass, gallium...High-repetition-rate femtosecond lasers enable the precise production of nanofoam from a wide range of materials. Here, the laser-based fabrication of nanofoam from silicon, borosilicate glass, sodalime glass, gallium lanthanum sulphide and lithium niobate is demonstrated, where the pore size of the nanofoam is shown to depend strongly on the material used, such that the pore width and nanofibre width appear to increase with density and thermal expansion coefficient of the material. In addition, the patterning of nanofoam on a glass slide, with fabricated pattern pixel resolution of ~35 μm, is demonstrated.展开更多
Diabetes is one of the most prevalent diseases in the world with high-mortality and complex complications including diabetic foot ulcer(DFU). It has been reported that the difficulties in repairing the wound related t...Diabetes is one of the most prevalent diseases in the world with high-mortality and complex complications including diabetic foot ulcer(DFU). It has been reported that the difficulties in repairing the wound related to DFU has much relationship with the wound infection,change of inflammatory responses, lack of extracellular matrix(ECM), and the failure of angiogenesis. Following the development of medical materials and pharmaceutical technology, nanofibers has been developed by electrospinning with huge porosity, excellent humidity absorption, a better oxygen exchange rate, and some antibacterial activities. That is to say, as a potential material, nanofibers must be a wonderful candidate for the DFU treatment with so many benefits. Careful selection of polymers from natural resource and synthetic resource can widen the nanofibrous application. Popular methods applied for the nanofibrous fabrication consist of uniaxial electrospinning and coaxial electrospinning. Furthermore, nanofibers loading chemical, biochemical active pharmaceutical ingredient(API)or even stem cells can be wonderful dosage forms for the treatment of DFU. This review summarizes the present techniques applied in the fabrication of nanofibrous dressing(ND)that utilizes a variety of materials and active agents to offer a better health care for the patients suffering from DFU.展开更多
A novel and high-efficiency coalescence membrane enhanced by nano-sized polyvinylidene fluoride(PVDF)nanofibers based on polyester(PET)substrate was fabricated using electrospinning method.The properties of the electr...A novel and high-efficiency coalescence membrane enhanced by nano-sized polyvinylidene fluoride(PVDF)nanofibers based on polyester(PET)substrate was fabricated using electrospinning method.The properties of the electrospun nanofibers such as roughness and surface morphology greatly affected the oil droplet interception efficiency and surface wettability of the membrane.A series of coalescence units were prepared with different layers of nanofibrous membrane and the separation efficiencies at different initial concentrations,flow rates,and oil types were tested.It is very interesting that the obtained nanofibrous membrane exhibited superoleophilicity in air but poor oleophilicity under water,which was beneficial to the coalescence process.The coalescence unit with four membrane layers had excellent performances under different initial concentrations and flow rates.The separation efficiency of the 4-layers unit remained above 98.2%when the initial concentration reached up to 2000 mg·L-1.Furthermore,the unit also exhibited good performance with the increasing oil density and viscosity,which is promising for large-scale oil wastewater treatment.展开更多
Polypyrrole (PPy) is a biocompatible polymer with good conductivity. Studies combining PPy with electrospinning have been reported; however, the associated decrease in PPy conductivity has not yet been resolved. We ...Polypyrrole (PPy) is a biocompatible polymer with good conductivity. Studies combining PPy with electrospinning have been reported; however, the associated decrease in PPy conductivity has not yet been resolved. We embedded PPy into poly(lactic acid) (PLA) nanofibers via electrospinning and fabricated a PLA/PPy nanofibrous scaffold containing 15% PPy with sustained conductivity and aligned topog- raphy, qhere was good biocompatibility between the scaffold and human umbilical cord mesenchymal stem cells as well as Schwann cells. Additionally, the direction of cell elongation on the scaffold was parallel to the direction of fibers. Our findings suggest that the aligned PLA/PPy nanofibrous scaffold is a promising biomaterial for peripheral nerve regeneration.展开更多
In this study, the mechanical properties of tungsten-rhenium wires with nanofibrous microstructure were investigated at both room temperature(RT) and 800?C. The strengthening mechanism associated to the nanofibrous mi...In this study, the mechanical properties of tungsten-rhenium wires with nanofibrous microstructure were investigated at both room temperature(RT) and 800?C. The strengthening mechanism associated to the nanofibrous microstructure was discussed. The results showed that the tungsten-rhenium wires with nanofibrous grains exhibited a very high tensile strength reaching values of 3.5 GPa and 4.4 GPa for the coarse(grains diameter of 240 nm) and fine(grains diameter of 80 nm) wires, respectively. With increasing the temperature from RT to 800?C, the tensile strength decreased slightly but still held high values(1.8 GPa and 3.8 GPa). All the fracture surfaces exhibited apparent necking and characteristics of spear-edge shaped fracture surface, indicating excellent ductility of the wires. A model of the strengthening mechanism of these tungsten-rhenium wires was proposed.展开更多
Reported here is a protocol to fabricate a biocatalyst with high enzyme loading and activity retention, from the conjugation of electrospun nanofibrous membrane having biomimetic phospholipid moiety and lipase. To imp...Reported here is a protocol to fabricate a biocatalyst with high enzyme loading and activity retention, from the conjugation of electrospun nanofibrous membrane having biomimetic phospholipid moiety and lipase. To improve the catalytic efficiency and activity of the immobilized enzyme, poly(acrylonitrile-co-2-methacryloyloxyethyl phosphorylcholine)s(PANCMPCs) were, respectively, electrospun into nanofibrous membranes with a mean diameter of 90 nm, as a support for enzyme immobilization. Lipase from Candida rugosa was immobilized on these nanofibrous membranes by adsorption. Properties of immobilized lipase on PANCMPC nanofibrous membranes were compared with those of the lipase immobilized on the polyacrylonitrile(PAN) nanofibrous and sheet membranes, respectively. Effective enzyme loading on the nanofibrous membranes was achieved up to 22.0 mg/g, which was over 10 times that on the sheet membrane. The activity retention of immobilized lipase increased from 56.4% to 76.8% with an increase in phospholipid moiety from 0 to 9.6%(molar fraction) in the nanofibrous membrane. Kinetic parameter Km was also determined for free and immobilized lipase. The Km value of the immobilized lipase on the nanofibrous membrane was obviously lower than that on the sheet membrane. The optimum pH was 7.7 for free lipase, but shifted to 8.3-8.5 for immobilized lipases. The optimum temperature was determined to be 35 ℃ for the free enzyme, but 42-44℃ for the immobilized ones, respectively. In addition, the thermal stability, reusability, and storage stability of the immobilized lipase were obviously improved compared to the free one.展开更多
Porphyrin-filled nanofibrous membranes were facilely prepared by electrospinning of the mixtures of poly(acrylonitrile-co-acrylic acid)(PANCAA) and porphyrins. 5,10,15,20-Tetraphenylporphyrin(TPP) and its metal-...Porphyrin-filled nanofibrous membranes were facilely prepared by electrospinning of the mixtures of poly(acrylonitrile-co-acrylic acid)(PANCAA) and porphyrins. 5,10,15,20-Tetraphenylporphyrin(TPP) and its metal-loderivatives(ZnTPP and CuTPP) were studied as filling mediators for the immobilization of redox enzyme. Results indicate that the introduction of TPP, ZnTPP and CuTPP improves the retention activity of the immobilized catalase. Among these three porphyrins, the ZnTPP-filled PANCAA nanofibrous membrane exhibits an activity retention of 93%, which is an exciting improvement. This improvement is attributed to both the strong catalase-porphyrin affinity and the possible facilitated electron transfer induced by the porphyrin as evidenced by quartz crystal microbalance (QCM) and fluorescence spectroscopy studies.展开更多
Polyacrylonitrile-metal sulfide nanocomposites with metal sulfide(Ag2S, CuS, PbS) nanoparticles homo- geneously dispersed on the polyacrylonitrile(PAN) nanofibre were synthesized by means of electrospinning techno...Polyacrylonitrile-metal sulfide nanocomposites with metal sulfide(Ag2S, CuS, PbS) nanoparticles homo- geneously dispersed on the polyacrylonitrile(PAN) nanofibre were synthesized by means of electrospinning techno- logy combined with gas-solid reaction. A series of experiments was performed to characterize the morphology varia- tion and distribution of the nanocrystalline. The result shows that the concentration of metal salt aqueous solution affects the size and morphology of metal sulfide nanoparticles during the chelating process. Further more, these metal ions nanoparticles were attached to the surface of the nanofibre homogeneously through chelating effect which will be propitious to prevent nanoparticles from aggregation. These results suggest that the method reported here is ex- tremely effective for synthesizing PAN-metal sulfide nanocomposites which have good visible light photocatalytic activity. Further more, this method could be extended to prepare other PAN-metal halides nanocomposites, too.展开更多
Following injury in central nervous system(CNS),there are pathological changes in the injured region,which include neuronal death,axonal damage and demyelination,inflammatory response and activation of glial cells.T...Following injury in central nervous system(CNS),there are pathological changes in the injured region,which include neuronal death,axonal damage and demyelination,inflammatory response and activation of glial cells.The proliferation of a large number of astrocytes results in the formation of glial scar.展开更多
Two types of micro/nano structures, microsphere and nanofibre, were prepared by elec- tro spinning technique and spray drying technique, with the soluble fluorinated poly ( ether ether ke- tone) (3F-PEEK) as the m...Two types of micro/nano structures, microsphere and nanofibre, were prepared by elec- tro spinning technique and spray drying technique, with the soluble fluorinated poly ( ether ether ke- tone) (3F-PEEK) as the matrix. The micro/nano structures were exhibited in the scanning electron microscope (SEM) micrograghs, and the separated nanofibre and microsphere were observed. The sizes of micro/nano structures were measured by the statistical analysis method. We designed exper- iments to connect up all the micro/nano structures to form new three dimensional micro/nano struc- tures that were observed by SEM. In the experiments, supercritical carbon dioxide ( C02 ) was se- lected as the welding solvent. A series of nanofibers were welded to form three dimensional netlike structures, and the particles were welded to form a porous film. The welding processes were studied by varying the exposure temperature, and the welding mechanism was discussed.展开更多
The protein-bound uremic toxins,represented by indoxyl sulfate(IS),have been associated with the progression of chronic kidney disease and the development of cardiovascular disease in the presence of impaired renal fu...The protein-bound uremic toxins,represented by indoxyl sulfate(IS),have been associated with the progression of chronic kidney disease and the development of cardiovascular disease in the presence of impaired renal function.Herein,we proposed a novel strategy of thin-film nanofibrous composite(TNFC)dialysis membrane combined with reduced graphene oxide(rGO)aerogel adsorbents for clinical removal of IS as well as high retention of proteins.The TFNC membrane was prepared by electrospinning in conjunction with coating-reaction method and proved to have good selectivity and permeability.To further improve the removal rate of toxins,we used a medium hydrothermal method following by freeze-drying treatment to obtain the r GO aerogel adsorbents.It exhibited excellent adsorption for IS with a maximum adsorption capacity of 69.40 mg·g^(-1)throughπ-πinteraction and hydrogen bonding interaction based on Langmuir isotherm models.Time-dependent absorption experiments showed that it reached adsorption equilibrium within 4 h,which was matched with the hemodialysis time.The coordination was significantly exhibited by introducing r GO aerogel blocks into the dialysate for absorbing the diffused free IS during hemodialysis.Taking the advantages of the TFNC dialysis membrane and the rGO aerogel,the volume of dialysate for hemodialysis was only one-tenth of that without adsorbent blocks but with very comparable dialysis performance(the clearance of IS at 51.8%and the retention of HSA over 98%),which could lighten conventional hemodialysis effectively and be benefit to realize the miniaturization of the hemodialysis equipment.Therefore,the coordination of the TFNC dialysis membrane and rGO aerogel adsorbents would open a new path for the development of portable artificial kidney.展开更多
文摘Thin PVA/nickel acetate composite fibres were prepared by using sol-gel processing and electrospinning technique. After calcination of the above precursor fibres, NiO nanofibres with a diameter of 50-150 nm could be successfully obtained. The fibres were characterized by SEM, FT-IR, WAXD, respectively.
基金supported by the Program for New Century Excellent Talents in University of China (Grant No. NCET-07-0472)the National Natural Science Foundation of China (Grant No. 10604038)
文摘Poly(vinylpyrrolidone)/tetrabutyl titanate (PVP/ [CH3(CH2)3O]4Ti) composite nanofibres are prepared by electrospinning. After calcining parts of composite nanofibres in air at 700 ~℃, petal-like TiO2 nanostructures are obtained. The characterizations of composite nanofibres and TiO2 nanostructures are carried out by a scanning electron microscope, an x-ray diffractometer, and an infrared spectrometer. Electrospun nanofibres are pressed into pellets under different pressures in order to explore their dielectric properties. It is found that the dielectric constants decrease with frequency increasing. The dielectric constant of the composite nanofibre pellet increases whereas its dielectric loss tangent decreases due to the doped titanium ions compared with those of pure PVP nanofibre pellets. In addition, it is observed that the dielectric constant of the composite nanofibre pellet decreases with the increase of the pressure applied in pelletization.
基金Project supported by the National Natural Science Foundation of China (Grant No 50674048)the Aerospace Science Foundation of China (Grant No 2007ZF52062)
文摘NiZn ferrite/polyvinylpyrrolidone composite fibres were prepared by sol,el assisted electrospinning. Ni0.5Zn0.5Fe2O4 nanofibres with a pure cubic spinel structure were obtained subsequently by calcination of the composite fibres at high temperatures. This paper investigates the thermal decomposition process, structures and morphologies of the electrospun composite fibres and the calcined Ni0.5Zn0.5Fe2O4 nanofibres at different temperatures by thermo-gravimetric and differential thermal analysis, x-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The magnetic behaviour of the resultant nanofibres was studied by a vibrating sample magnetometer. It is found that the grain sizes of the nanofibres increase significantly and the nanofibre morphology graduMly transforms from a porous structure to a necklace-like nanostructure with the increase of calcination tempera-ture. The Ni0.5Zn0.5Fe2O4 nanofibres obtained at 1000℃ for 2h are characterized by a necklace-like morphology and diameters of 100-200nm. The saturation magnetization of the random Ni0.5Zn0.5Fe2O4 nanofibres increases from 46.5 to 90.2 emu/g when the calcination temperature increases from 450 to 1000℃. The coercivity reaches a maximum value of 11.0 kA/m at a calcination temperature of 600℃. Due to the shape anisotropy, the aligned Ni0.5Zn0.5Fe2O4 nanofibres exhibit an obvious magnetic anisotropy and the ease magnetizing direction is parallel to the nanofibre axis.
文摘Ca and Mn co-doped BiFeO3 ultrafine nanofibres were prepared with the purpose of improving magnetic and photocatalytic performances of the one-dimensional multiferroic material. Impurity phase introduced by both Bi fluctuation and Mn substitution can be suppressed by Ca doping and a space group transition from R3c to C222 can also be triggered by Bi-site doping. With co-substitution of Mn into iron site, the Ca0.15Bi0.85Mn0.05Fe0.95O3 nanofibres presented a larger saturation magnetization than the singly Ca doping samples, possibly due to the increased double exchange interation of Fe3+-O-Fe2+, strengthened by Ca and Mn. Photocatalytic degradation test witnessed a similar drop-and-rise performance with the magnetism.
基金financially supported by National Key Research and Development Program of China (2022YFB3804903, 2022YFB3804900)the National Natural Science Foundation of China (No. 52273052)+2 种基金the Fundamental Research Funds for the Central Universities (No. 2232023Y01)the Program of Shanghai Academic/Technology Research Leader (No. 21XD1420100)the International Cooperation Fund of Science and Technology Commission of Shanghai Municipality (No. 21130750100)。
文摘Nanofiber membranes(NFMs) have become attractive candidates for next-generation flexible transparent materials due to their exceptional flexibility and breathability. However, improving the transmittance of NFMs is a great challenge due to the enormous reflection and incredibly poor transmission generated by the nanofiber-air interface. In this research, we report a general strategy for the preparation of flexible temperature-responsive transparent(TRT) membranes,which achieves a rapid transformation of NFMs from opaque to highly transparent under a narrow temperature window. In this process, the phase change material eicosane is coated on the surface of the polyurethane nanofibers by electrospray technology. When the temperature rises to 37 ℃, eicosane rapidly completes the phase transition and establishes the light transmission path between the nanofibers, preventing light loss from reflection at the nanofiber-air interface. The resulting TRT membrane exhibits high transmittance(> 90%), and fast response(5 s). This study achieves the first TRT transition of NFMs, offering a general strategy for building highly transparent nanofiber materials, shaping the future of next-generation intelligent temperature monitoring, anti-counterfeiting measures, and other high-performance devices.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean Government(the Ministry of Science and ICT(MSIT))(No.2021R1A2C2006013)the Bio&Medical Technology Development Program of the NRF funded by the Korean government(MSIT)(No.RS-2023-00223591)the Korea Medical Device Development Fund grant funded by the Korean government(the MSIT,the MOTIE,the Ministry of Health and Welfare,the Ministry of Food and Drug Safety)(NTIS Number:9991006781,KMDF_PR_(2)0200901_0108)。
文摘Current therapeutic approaches for volumetric muscle loss(VML)face challenges due to limited graft availability and insufficient bioactivities.To overcome these limitations,tissue-engineered scaffolds have emerged as a promising alternative.In this study,we developed aligned ternary nanofibrous matrices comprised of poly(lactide-co-ε-caprolactone)integrated with collagen and Ti_(3)C_(2)T_(x)MXene nanoparticles(NPs)(PCM matrices),and explored their myogenic potential for skeletal muscle tissue regeneration.The PCM matrices demonstrated favorable physicochemical properties,including structural uniformity,alignment,microporosity,and hydrophilicity.In vitro assays revealed that the PCM matrices promoted cellular behaviors and myogenic differentiation of C2C12 myoblasts.Moreover,in vivo experiments demonstrated enhanced muscle remodeling and recovery in mice treated with PCM matrices following VML injury.Mechanistic insights from next-generation sequencing revealed that MXene NPs facilitated protein and ion availability within PCM matrices,leading to elevated intracellular Ca^(2+)levels in myoblasts through the activation of inducible nitric oxide synthase(i NOS)and serum/glucocorticoid regulated kinase 1(SGK1),ultimately promoting myogenic differentiation via the m TOR-AKT pathway.Additionally,upregulated i NOS and increased NO–contributed to myoblast proliferation and fiber fusion,thereby facilitating overall myoblast maturation.These findings underscore the potential of MXene NPs loaded within highly aligned matrices as therapeutic agents to promote skeletal muscle tissue recovery.
基金financially supported by the National Key Research and Development Program of China(2018YFA0703003)the National Natural Science Foundation of China (52125501)+2 种基金the Key Research Project of Shaanxi Province (2021LLRH-08,2021GXLH-Z-028)the Program for Innovation Team of Shaanxi Province (2023-CX-TD-17)the Fundamental Research Funds for the Central Universities。
文摘Three-dimensional(3D) printing provides a promising way to fabricate biodegradable scaffolds with designer architectures for the regeneration of various tissues.However,the existing3D-printed scaffolds commonly suffer from weak cell-scaffold interactions and insufficient cell organizations due to the limited resolution of the 3D-printed features.Here,composite scaffolds with mechanically-robust frameworks and aligned nanofibrous architectures are presented and hybrid manufactured by combining techniques of 3D printing,electrospinning,and unidirectional freeze-casting.It was found that the composite scaffolds provided volume-stable environments and enabled directed cellular infiltration for tissue regeneration.In particular,the nanofibrous architectures with aligned micropores served as artificial extracellular matrix materials and improved the attachment,proliferation,and infiltration of cells.The proposed scaffolds can also support the adipogenic maturation of adipose-derived stem cells(ADSCs)in vitro.Moreover,the composite scaffolds were found to guide directed tissue infiltration and promote nearby neovascularization when implanted into a subcutaneous model of rats,and the addition of ADSCs further enhanced their adipogenic potential.The presented hybrid manufacturing strategy might provide a promising way to produce additional topological cues within 3D-printed scaffolds for better tissue regeneration.
基金supported by the Liaoning Pan Deng Xue Zhe Scholar(No.XLYC2002061)the Overseas Expertise Introduction Project for Discipline Innovation(“111 Project”)(No.D20029)+5 种基金X.G.acknowledges the Educational Department of Liaoning Province(grant No.LJKZ0925),(Youth Project,grant No.LJKQZ2021035)the international postdoctoral exchange fellowship program(grant No.PC2021047)H.B.thanks the financial support from National Natural Science Foundation of China(grant No.82050410448)Fellowship of China Postdoctoral Science Foundation(grant No.2021MD703857)D.Cun acknowledges financial support from Ministry of Education Chunhui Program(2020)VF acknowledges VILLUM FONDEN for supporting the project via the Villum Young Investigator Grant(grant No.19175).
文摘Burn injury is a serious public health problem and scientists are continuously aiming to develop promising biomimetic dressings for effective burn wound management.In this study,a greater efficacy in burn wound healing and the associated mechanisms ofα-lactalbumin(ALA)based electrospun nanofibrous scaffolds(ENs)as compared to other regenerative protein scaffolds were established.Bovine serum albumin(BSA),collagen type I(COL),lysozyme(LZM)and ALA were separately blended with poly(ε-caprolactone)(PCL)to fabricate four different composite ENs(LZM/PCL,BSA/PCL,COL/PCL and ALA/PCL ENs).The hydrophilic composite scaffolds exhibited an enhancedwettability and variablemechanical properties.The ALA/PCL ENs demonstrated higher levels of fibroblast proliferation and adhesion than the other composite ENs.As compared to PCL ENs and other composite scaffolds,the ALA/PCL ENs also promoted a better maturity of the regenerative skin tissues and showed a comparable wound healing effect to Collagen sponge^(■)on third-degree burn model.The enhanced wound healing activity of ALA/PCL ENs compared to other ENs could be attributed to their ability to promote serotonin production at wound sites.Collectively,this investigation demonstrated that ALA is a unique protein with a greater potential for burn wound healing as compared to other regenerative proteins when loaded in the nanofibrous scaffolds.
文摘Due to some intrinsic functional behavior of alginate, many potential applications in the healthcare industry especially in wound care sector are observed. Many researches have been carried out to develop potential biomedical biocompatible products in different forms from alginate fibres. Alginate nanofibres were prepared from sodium alginate polymer with the presence of poly-(ethylene oxide) (PEO), a small amount of Triton ×100 surfactant. A homogeneous spinning solution was prepared for producing Na-alginate/PEO nanofibers in electrospinning device. Nanofibres were produced by electrospinning from 70:30 and 80:20 Na-alginate/PEO of 4% solution. After a series of trials, the electrospinning parameters were optimized at 16 cm working distance, 0.4 mL/h flow rate and 10.5 kV applied voltage. The results show that the 4 wt% of 70:30 Na-alginate/PEO solution with 0.5 wt% Triton × 100 surfactant yielded smooth and stable electrospinning. The surface morphology of the fibres was investigated using Scanning Electron Microscope (SEM) and found the uniform fibres with an average diameter of 124 nm containing few thick or spindle-like fibres. FTIR investigation identified the chemical structure and molecular changes that occurred in the fibers.
文摘High-repetition-rate femtosecond lasers enable the precise production of nanofoam from a wide range of materials. Here, the laser-based fabrication of nanofoam from silicon, borosilicate glass, sodalime glass, gallium lanthanum sulphide and lithium niobate is demonstrated, where the pore size of the nanofoam is shown to depend strongly on the material used, such that the pore width and nanofibre width appear to increase with density and thermal expansion coefficient of the material. In addition, the patterning of nanofoam on a glass slide, with fabricated pattern pixel resolution of ~35 μm, is demonstrated.
基金financially supported by the National Natural Science Foundation of China(No.81600353)the Career Development Program for Young Teachers in Shenyang Pharmaceutical University
文摘Diabetes is one of the most prevalent diseases in the world with high-mortality and complex complications including diabetic foot ulcer(DFU). It has been reported that the difficulties in repairing the wound related to DFU has much relationship with the wound infection,change of inflammatory responses, lack of extracellular matrix(ECM), and the failure of angiogenesis. Following the development of medical materials and pharmaceutical technology, nanofibers has been developed by electrospinning with huge porosity, excellent humidity absorption, a better oxygen exchange rate, and some antibacterial activities. That is to say, as a potential material, nanofibers must be a wonderful candidate for the DFU treatment with so many benefits. Careful selection of polymers from natural resource and synthetic resource can widen the nanofibrous application. Popular methods applied for the nanofibrous fabrication consist of uniaxial electrospinning and coaxial electrospinning. Furthermore, nanofibers loading chemical, biochemical active pharmaceutical ingredient(API)or even stem cells can be wonderful dosage forms for the treatment of DFU. This review summarizes the present techniques applied in the fabrication of nanofibrous dressing(ND)that utilizes a variety of materials and active agents to offer a better health care for the patients suffering from DFU.
基金supported by the National Key Research and Development Program of China(No.2017YFB0308000)the National Natural Science Foundation of China(No.21706259)+3 种基金the State Key Laboratory of Heavy Oil Processing(SKLOP201903001)Guizhou Science Technology Support Program([2019]2839)the Natural Science Youth Foundation of Shanxi Province(No.201701D221033)Program of Innovation Academy for Green Manufacture,CAS(IAGM2020C04)。
文摘A novel and high-efficiency coalescence membrane enhanced by nano-sized polyvinylidene fluoride(PVDF)nanofibers based on polyester(PET)substrate was fabricated using electrospinning method.The properties of the electrospun nanofibers such as roughness and surface morphology greatly affected the oil droplet interception efficiency and surface wettability of the membrane.A series of coalescence units were prepared with different layers of nanofibrous membrane and the separation efficiencies at different initial concentrations,flow rates,and oil types were tested.It is very interesting that the obtained nanofibrous membrane exhibited superoleophilicity in air but poor oleophilicity under water,which was beneficial to the coalescence process.The coalescence unit with four membrane layers had excellent performances under different initial concentrations and flow rates.The separation efficiency of the 4-layers unit remained above 98.2%when the initial concentration reached up to 2000 mg·L-1.Furthermore,the unit also exhibited good performance with the increasing oil density and viscosity,which is promising for large-scale oil wastewater treatment.
基金financially supported by Tsinghua University Initiative Scientific Research Program,No.20131089199the National Key Research and Development Program of China,No.2016YFB0700802the National Program on Key Basic Research Project of China(973 Program),No.2012CB518106,2014CB542201
文摘Polypyrrole (PPy) is a biocompatible polymer with good conductivity. Studies combining PPy with electrospinning have been reported; however, the associated decrease in PPy conductivity has not yet been resolved. We embedded PPy into poly(lactic acid) (PLA) nanofibers via electrospinning and fabricated a PLA/PPy nanofibrous scaffold containing 15% PPy with sustained conductivity and aligned topog- raphy, qhere was good biocompatibility between the scaffold and human umbilical cord mesenchymal stem cells as well as Schwann cells. Additionally, the direction of cell elongation on the scaffold was parallel to the direction of fibers. Our findings suggest that the aligned PLA/PPy nanofibrous scaffold is a promising biomaterial for peripheral nerve regeneration.
基金financially supported by the National Natural Science Foundation of China(No.51271021)Beijing Natural Science Foundation(No.2162025)State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing
文摘In this study, the mechanical properties of tungsten-rhenium wires with nanofibrous microstructure were investigated at both room temperature(RT) and 800?C. The strengthening mechanism associated to the nanofibrous microstructure was discussed. The results showed that the tungsten-rhenium wires with nanofibrous grains exhibited a very high tensile strength reaching values of 3.5 GPa and 4.4 GPa for the coarse(grains diameter of 240 nm) and fine(grains diameter of 80 nm) wires, respectively. With increasing the temperature from RT to 800?C, the tensile strength decreased slightly but still held high values(1.8 GPa and 3.8 GPa). All the fracture surfaces exhibited apparent necking and characteristics of spear-edge shaped fracture surface, indicating excellent ductility of the wires. A model of the strengthening mechanism of these tungsten-rhenium wires was proposed.
基金Supported by the National Natural Science Foundation of China for Distinguished Young Scholars(No50625309)the National Postdoctoral Science Foundation of China(No20060400337)
文摘Reported here is a protocol to fabricate a biocatalyst with high enzyme loading and activity retention, from the conjugation of electrospun nanofibrous membrane having biomimetic phospholipid moiety and lipase. To improve the catalytic efficiency and activity of the immobilized enzyme, poly(acrylonitrile-co-2-methacryloyloxyethyl phosphorylcholine)s(PANCMPCs) were, respectively, electrospun into nanofibrous membranes with a mean diameter of 90 nm, as a support for enzyme immobilization. Lipase from Candida rugosa was immobilized on these nanofibrous membranes by adsorption. Properties of immobilized lipase on PANCMPC nanofibrous membranes were compared with those of the lipase immobilized on the polyacrylonitrile(PAN) nanofibrous and sheet membranes, respectively. Effective enzyme loading on the nanofibrous membranes was achieved up to 22.0 mg/g, which was over 10 times that on the sheet membrane. The activity retention of immobilized lipase increased from 56.4% to 76.8% with an increase in phospholipid moiety from 0 to 9.6%(molar fraction) in the nanofibrous membrane. Kinetic parameter Km was also determined for free and immobilized lipase. The Km value of the immobilized lipase on the nanofibrous membrane was obviously lower than that on the sheet membrane. The optimum pH was 7.7 for free lipase, but shifted to 8.3-8.5 for immobilized lipases. The optimum temperature was determined to be 35 ℃ for the free enzyme, but 42-44℃ for the immobilized ones, respectively. In addition, the thermal stability, reusability, and storage stability of the immobilized lipase were obviously improved compared to the free one.
基金Supported by the National High-Tech Research and Development Program of China(No.2007AA10Z301) the National Natural Science Foundation of China for Distinguished Young Scholars(No.50625309)
文摘Porphyrin-filled nanofibrous membranes were facilely prepared by electrospinning of the mixtures of poly(acrylonitrile-co-acrylic acid)(PANCAA) and porphyrins. 5,10,15,20-Tetraphenylporphyrin(TPP) and its metal-loderivatives(ZnTPP and CuTPP) were studied as filling mediators for the immobilization of redox enzyme. Results indicate that the introduction of TPP, ZnTPP and CuTPP improves the retention activity of the immobilized catalase. Among these three porphyrins, the ZnTPP-filled PANCAA nanofibrous membrane exhibits an activity retention of 93%, which is an exciting improvement. This improvement is attributed to both the strong catalase-porphyrin affinity and the possible facilitated electron transfer induced by the porphyrin as evidenced by quartz crystal microbalance (QCM) and fluorescence spectroscopy studies.
文摘Polyacrylonitrile-metal sulfide nanocomposites with metal sulfide(Ag2S, CuS, PbS) nanoparticles homo- geneously dispersed on the polyacrylonitrile(PAN) nanofibre were synthesized by means of electrospinning techno- logy combined with gas-solid reaction. A series of experiments was performed to characterize the morphology varia- tion and distribution of the nanocrystalline. The result shows that the concentration of metal salt aqueous solution affects the size and morphology of metal sulfide nanoparticles during the chelating process. Further more, these metal ions nanoparticles were attached to the surface of the nanofibre homogeneously through chelating effect which will be propitious to prevent nanoparticles from aggregation. These results suggest that the method reported here is ex- tremely effective for synthesizing PAN-metal sulfide nanocomposites which have good visible light photocatalytic activity. Further more, this method could be extended to prepare other PAN-metal halides nanocomposites, too.
基金supported by National Basic Research Program of China(973 Program,2014CB542205)Hong Kong RGC grant+2 种基金Hong Kong Health and Medical Research Fundfoundation for Distinguished Young Talents in Higher Education of Guangdong(Yq2013023)the Leading Talents of Guangdong Province(87014002)
文摘Following injury in central nervous system(CNS),there are pathological changes in the injured region,which include neuronal death,axonal damage and demyelination,inflammatory response and activation of glial cells.The proliferation of a large number of astrocytes results in the formation of glial scar.
基金Supported by the National Natural Science Foundation of China(51103010)
文摘Two types of micro/nano structures, microsphere and nanofibre, were prepared by elec- tro spinning technique and spray drying technique, with the soluble fluorinated poly ( ether ether ke- tone) (3F-PEEK) as the matrix. The micro/nano structures were exhibited in the scanning electron microscope (SEM) micrograghs, and the separated nanofibre and microsphere were observed. The sizes of micro/nano structures were measured by the statistical analysis method. We designed exper- iments to connect up all the micro/nano structures to form new three dimensional micro/nano struc- tures that were observed by SEM. In the experiments, supercritical carbon dioxide ( C02 ) was se- lected as the welding solvent. A series of nanofibers were welded to form three dimensional netlike structures, and the particles were welded to form a porous film. The welding processes were studied by varying the exposure temperature, and the welding mechanism was discussed.
基金supported by the Fundamental Research Funds for the Central Universities(2232020A-04)Natural Science Foundation of Shanghai City(19ZR1401300)。
文摘The protein-bound uremic toxins,represented by indoxyl sulfate(IS),have been associated with the progression of chronic kidney disease and the development of cardiovascular disease in the presence of impaired renal function.Herein,we proposed a novel strategy of thin-film nanofibrous composite(TNFC)dialysis membrane combined with reduced graphene oxide(rGO)aerogel adsorbents for clinical removal of IS as well as high retention of proteins.The TFNC membrane was prepared by electrospinning in conjunction with coating-reaction method and proved to have good selectivity and permeability.To further improve the removal rate of toxins,we used a medium hydrothermal method following by freeze-drying treatment to obtain the r GO aerogel adsorbents.It exhibited excellent adsorption for IS with a maximum adsorption capacity of 69.40 mg·g^(-1)throughπ-πinteraction and hydrogen bonding interaction based on Langmuir isotherm models.Time-dependent absorption experiments showed that it reached adsorption equilibrium within 4 h,which was matched with the hemodialysis time.The coordination was significantly exhibited by introducing r GO aerogel blocks into the dialysate for absorbing the diffused free IS during hemodialysis.Taking the advantages of the TFNC dialysis membrane and the rGO aerogel,the volume of dialysate for hemodialysis was only one-tenth of that without adsorbent blocks but with very comparable dialysis performance(the clearance of IS at 51.8%and the retention of HSA over 98%),which could lighten conventional hemodialysis effectively and be benefit to realize the miniaturization of the hemodialysis equipment.Therefore,the coordination of the TFNC dialysis membrane and rGO aerogel adsorbents would open a new path for the development of portable artificial kidney.