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1.
Phytoncide, a volatile essential oil produced by plants and trees, has not only anti-microbial activity, but also a stress relieving effect. We prepared a sheath/core type melt-spun fiber that releases phytoncide for a prolonged time. The fiber is comprised of a nylon sheath and a polypropylene (PP) core material. Phytoncide-containing microcapsules are embedded within the core part. The phytoncide microcapsule-containing nylon/PP sheath/core (M-Ny/PP) fiber has suitable mechanical properties for textile application. The phytoncide release from the microcapsule-containing the PP fiber (M-PP) reached a plateau level after 4 days and maintained that level for an additional 7 days, indicating a zero-order release after the initial burst. The M-Ny/PP fiber emitted the volatile phytoncide even though the fiber was spun at 250 °C. The release of phytoncide decreased in the M-Ny/PP fiber compared to the phytoncide microcapsule-containing PP (M-PP) fiber due to the dense sheath layer.  相似文献   

2.
Biocompatible polyvinyl alcohol (PVA)-styrylpyridinium (SbQ)/β-cyclodextrin (β-CD) composite nanofibers were obtained by electrospinning in this study. PVA-SbQ was used as the foundation polymer as well as crosslinking agent, β-CD was incorporated to achieve expected properties such as improved mechanical properties and thermal stability. The Fourier transform infrared spectroscopy (FTIR) spectra confirmed the existence of β-CD, and the morphologies and average fiber diameters of the electrospun composite nanofibers were also analyzed by SEM. X-ray diffraction patterns (XRD) of PVA-SbQ/β-CD composite nanofibers revealed that the inclusion of β-CD in the nanofibers affected the ordered phase of PVA. Besides, the thermal analyses revealed the improvement in the thermal properties for PVA-SbQ/β-CD composite nanofibers. It was found that the crosslinked composite nanofibers showed a clear higher tensile strength (TS) as well as a greater elongation at break (EB). Eventually, antifungal drug griseofulvin (GSV) has been loaded into the composite nanofibers by formation of its inclusion complex with β-CD in aqueous solution, ultraviolet light (UV-Vis) spectral analysis showed that the drug-loading nanofibers had certain sustained release effect.  相似文献   

3.
Nanospider technology as a modified electrospinning technique was used for the fabrication of electrospun nanofibers based on poly(vinyl alcohol) (PVA)/poly(ethylene oxide) (PEO) blend as drug delivery system (DDS) for metronidazole (MTZ) as an antimicrobial drug. Electrospun PVA/PEO/MTZ composite nanofibers were stabilized against disintegration in water by heating in oven at 110°C, or by soaking in isopropyl alcohol for 6 hrs. Incorporation of MTZ into electrospun nanofibers was confirmed by SEM, FT-IR spectra and TGA. The drug release results showed that the burst release was suppressed with stabilized electrospun nanofibers compared with non-stabilized ones. Electrospun PVA/PEO/MTZ composite nanofibers exhibited remarkable antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger, Penicillium notatum and Aspergillus flavus which varies with the species of the tested organisms.  相似文献   

4.
The electrospinnability of aloe vera gel and the release mechanism as well as the kinetic of its release from poly vinyl alcohol (PVA) nanofibrous matrix is reported. Addition of PVA by an amount of only 1 % (w/w) to aloe vera solution made its electrospinning possible leading, to the fabrication of aloe vera nanofiber (99 %) with an average diameter of around 80 nm. Electrospinning of aloe vera-PVA solutions (25-75, 50-50, 75-25) led to the fabrication of nanofibers with average diameter of around 55, 105 and 110 nm, respectively. FTIR analysis showed no reaction between aloe vera and PVA. X-ray diffraction patterns showed no considerable effect from aloe vera on the amorphous structure of PVA. The release mechanism of aloe vera from PVA matrix in phosphate buffer solution was of Ficki type and the kinetic of the release followed Higuchi model. Aloe vera or aloe vera-PVA electrospun nanofibers may be used as an aloe vera release system in wound care. In a phosphate buffer solution, at least 60 percent of aloe vera is released in the first hour and about 90 % of aloe vera is released in 2-4 hours depending on the diameter of the nanofibers.  相似文献   

5.
Controlled release of drugs is important to reduce the amount of medication in treatment of any diseases and improves life quality. Poly(e-caprolactone) (PCL) has a low biodegradation rate that is a disadvantage in the biomedical and pharmaceutical fields. Poly(N-vinyl-2-pyrrolidone) (PVP) is a water-soluble polymer that to overcome of PCL low biodegradation rate, electrospinning of PCL blended with PVP was used for shell of nanofibers with controllable degradation rates and drug release rates. Oral and vaginal mucosal infections mainly caused by candida albicans. It is usually a harmless commensal organism; however it is known as an opportunistic pathogen for almost immunologically week and immune compromised people. Amphotericin-B (AmB) is a strong polyene antifungal antibiotic that has a significantly efficacy on candida albicans. This study is manufactured and optimized the PVP-PCL shell/PVP-AmB core nanofiberous tissue by working distance and feed flow rate for controlled drug release. AmB with PVP was successfully inserted into the core. PVPPCL shell (50/50)/PVP-AmB core nanofiberous were electrospinning with two optimum distances working and two flow rates. The mechanical properties of coaxial nanofibers were analyzed by instron machine. Scanning electron microscopy and transmission electron microscopy was used for analysis morphology. Further, drug release test were done for coaxial nanofibers with AmB different morphologies. The effect of flow rate and working distance on morphology and mechanical properties were evaluated by statistical two-way analysis of the variance (ANOVA). The diameter averages of nanofibers were decreased significantly by increasing working distance. Moreover, the stress and strain were increased by increasing working distance. Coaxial nanofibers biodegradability rate and drug release of nanofibers were increased also by increasing working distance and flow rate of core. Nanofibers drug release mechanism was indicated by Korsmeyer-Peppas which they followed fick′s lows and Higuchi model significantly. Also, results presented that biodegradability and drug release rate accelerate with increasing the working distance and increasing the amount of PVP in core.  相似文献   

6.
We reported the preparation and characterization of the poly(vinyl alcohol) (PVA)/BaSO4 hybrid nanofibers prepared by normal and ultrasonic electrospinning, respectively. Compared to normal electrospinning, BaSO4 particles in the resultant PVA/BaSO4 hybrid nanofibers prepared by ultrasonic electrospinning were well-dispersed without severe agglomerations, as confirmed by scanning electron microscopy (SEM) analysis. X-ray diffraction (XRD) analysis indicated that typical crystalline peaks of PVA and BaSO4 particles were dramatically decreased by ultrasonication during electrospinning. Moreover, the size of BaSO4 aggregates became smaller.  相似文献   

7.
The aim of the present study was to prepare nanofibers loaded with montelukast, a cysteinyl leukotrienes (CysLTs) inhibitor, with anti-inflammatory properties effective on wound healing. Polymeric nanofibers containing montelukast were spun by electrospinning method using different ratios of the blend of two biodegradable polymers of poly(methyl vinyl etherco-maleic acid) (PMVEMA) and poly(lactic-co-glycolic acid) (PLGA) at the total polymer concentration of 37 %, the distance of the needle to rotating screen of 19 cm, the voltage of 12 Kv and the rate of injection of 0.2 ml/h. The ratio of two polymers in the blend and the concentration of montelukast were optimized based on the diameter of the nanofibers, drug loading percent and release efficiency by a full factorial design. The morphology, diameter and diameter distribution of the nanofibers were studied by scanning electron microscopy (SEM). Drug loading percent in the nanofibers was determined by extracting the loaded drug from a specific surface of the nanofibers which was subsequently analyzed spectrophotometrically. The drug release rate from the nanofibers was studied in phosphate buffer solution (pH 7.4) containing 0.5 % Tween 20 at predetermined time intervals until 10 days. The cytotoxicity of the designed nanofibers was evaluated on mouse fibroblast cells using trypan blue method, their platelet adherence property was quantified by measuring the lactate dehydrogenase (LDH) activity and confirmed by SEM micrographs. The optimized ratio of PLGA/PMVEMA was 3:1 with the total concentration of polymers as 37 % loaded with 30 % of montelukast produced nanofibers with a diameter of 157.6 nm, drug loading percent of 43.7 % and release efficiency of 75 % after 10 days. The cell viability was similar in nanofibers and the negative control group. The platelets adhesion to the nanofibers was more than the negative control group (p<0.05).  相似文献   

8.
As a kind of high-performance fibers, PTFE fiber has been widely used in many fields because of its unique characteristics. In this study, the poly(tetrafloroethylene) (PTFE) nanofibers manufactured by electrospinning method was reported. The gel-spinning solution of poly(tetrafluoroethylene)/poly(vinyl alcohol)/boric acid (PTFE/PVA/BA), which was prepared by the gel process of the mixture of PTFE, PVA, BA and redistilled water, was electrospun to form PTFE/PVA/BA composite nanofibers. After calcinating, the PTFE nanofibers with diameters of 200 nm to 1000 nm were obtained. The fibers before and after calcinating were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), FT-IR spectrum analysis and X-ray photoelectron spectroscopy (XPS), respectively, and the mechanical and hydrophobic properties of the fibers were also investigated. The results showed that the PTFE nanofiber membranes could be electrospun effectively used the gel-spinning solution of PTFE/PVA/BA, and may realize the applications in the fields of high-temperature filtration, catalyst supports, battery separator and so on.  相似文献   

9.
New generation wound dressings require the criteria that both bioactive and conventional wound dressing materials can recompense the fundamental properties like defense of wound from microbial invasion, dehydration during the wound care duration and mimic the healing process. In this study, functional double-layered nanofibrous composite membranes were fabricated via electrospinning method. The matrices consist of a sheet of ampicillin loaded poly(2-hydroxylethyl methacrylate/polyacrylic acid (pHEMA/pAA) nanofibers on the upper side (first layer: pH sensitive antibacterial barrier) and a sheet of poly(ε-caprolactone) (PCL)/gelatin nanofibers (second layer: bioactive part). Ampicillin was successfully incorporated to double-layered matrices which greatly changed the mechanical properties, biodegradability and water uptake ratios (up to 4 fold higher values). The success of the antimicrobial activity of ampicillin on Staphylococcus aureus and Escherichia coli was indicated by the inhibition zone test. pH sensitivity was confirmed by the swelling and ampicillin release studies by shifting pH value to basic environment. Thus, double-layered pHEMA-pAA nanofibers suggest as a potential wound dressing material for its pH sensitive drug delivery ability and its bioactive part.  相似文献   

10.
Synthesis of biocompatible polymer nanofibers is valuable, due to their use as a cover for burns and as a replacement for bandage because of their antimicrobial properties. In this study, electrospinning of chitosan(Ch) and nanofibers synthesis with antibacterial properties was investigated. Nanofibers with antibacterial properties were synthesized by electrospun of Ch/poly(L-lactide)(PLA)/Imipenem(Imi) polymer solution. The results showed that the optimized ratio of Ch/PLA polymer solution was ratio of 50:50 and Ch 2 wt% and PLA 10 wt% polymer solution was the best weight percentage for nanofiber preparation. Also, the average diameter of Ch/PLA/Imi nanofibers was 143 nm and measured with ImageJ software. Afterwards, the antibacterial properties of Imi as additives (with different percentages) was studied in the polymer solution. The scanning electron microscopy (SEM) images and antibacterial tests were showed that the electrospun of Ch/PLA/Imi polymeric nanofibers were effective against Gram negative bacteria Escherichia coli (E. coli) and inhibited growth of E. coli. The growth and viability percentage of fibroblast cells with nanofibers in αMEM culture are at desirable levels after 6 days.  相似文献   

11.
GSP/gelatin composite nanofiber membranes containing silver nanoparticles were successfully fabricated as a novel biomaterial by electrospinning. The silver nanoparticles (AgNPs) were synthesized with the grape seed polyphenols (GSP) as reducing agent in aqueous solution of gelatin, and then the GSP/gelatin/AgNPs mixed solution was electrospun into nanofibers at 55 °C. The scanning electron microscopy (SEM) confirmed that the composite fibers were uniform and the average fiber diameter ranged between 150 nm and 230 nm with an increase in applied potentials from 14 kV to 22 kV. And the transmission electron microscopy (TEM) showed that silver nanoparticles distributed individually in the fibers with the average particle size of about 11 nm. Furthermore, the ultraviolet visible spectrophotometer (UV-vis spectroscopy) test demonstrated that all of Ag+ converted to Ag0 when the concentration of gelatin was 24 wt% and the mass ratio of GSP to AgNO3 was about 5:2. The antibacterial activities of the fiber membranes against E.coli and S.aureus were measured via a shake flank test and demonstrated good performance after the importation of silver nanopaticles. Cytotoxicity testing also revealed that fiber membranes contained silver nanoparticles had no cyto-toxic. All the results indicated that the GSP was effective for the formation and stabilization of silver nanoparticles in composite nanofibers mats which had the potential for applications in antimicrobial tissue engineering and wound dressing.  相似文献   

12.
Gallium arsenide (GaAs) does have superior electronic properties compared with silicon. For instant, it has a higher saturated electron velocity and higher electron mobility. Weak mechanical properties and high production cost are the main drawbacks of this interesting semiconductor. In this study, we are introducing production of GaAs nanofibers by electrospinning methodology as a very low cost and yielding distinct product technique. In general, nano-fibrous shape is strongly improving the physical properties due to the high surface area to volume ratio of this nanostructure. The mechanical and environmental properties of the GaAs compound have been modified since GaAs nanofibers have been produced as a core inside a poly(vinyl alcohol) (PVA) shell. GaAs/PVA nanofibers were prepared by electrospinning of gallium nitrate/PVA solution in presence of arsenic vapor. The whole process was carried out in a closed hood equipped with nitrogen environment. FT-IR, XPS, TGA and UV-Vis spectroscopy analyses were utilized to confirm formation of GaAs compound. Transmission electron microscope (TEM) analysis has revealed that the synthesized GaAs compound is crystalline and does have nano-fibrous shape as a core inside PVA nanofibers. To precisely recommend the prepared GaAs nanofiber mats to be utilized in different applications, we have measured the electric conductivity and the band gap energies of the prepared nanofiber mats. Overall, the obtained results affirmed that the proposed strategy successfully remedied the drawbacks of the reported GaAs structures and did not affect the main physical properties of this important semiconductor.  相似文献   

13.
A series of blend nanofiber mats comprising poly(vinyl alcohol) (PVA) and polyurethane (PU) were prepared by dual-jet electrospinning in various parameters. Orthogonal experimental design was used to investigate how those parameters affected on fiber diameters and fiber diameter distribution. Altogether three parameters having three levels each were chosen for this study. The chosen parameters were tip-to-collector distance (TCD), voltage and tip-to-tip distance (TTD). Fiber diameters, thermal properties, mechanical properties and hydrophilicity of the blend nanofiber mats were examined by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), tensile test, contact angle and water absorption test, respectively. The results showed that the optimum conditions for PVA/PU blend nanofiber mats fabricated by dual-jet electrospinning were TCD of 20 cm, voltage of 18 kV and TTD of 4 cm. Besides, the thermal stability of PVA/PU blend nanofiber mats had been improved compared with pure nanofibers. Furthermore, the elongation and tensile strength of the blend nanofiber mats were significantly increased compared with pure PVA and pure PU, respectively. And the blend nanofiber mats exhibited well hydrophilicity.  相似文献   

14.
Poly(meta-phenylene isophthalamide, PMIA)-based phase change fibers (PCFs) with fatty acid ester (i.e. HPCMEs) as the functional ingredient were successfully fabricated by emulsion electrospinning. Subsequent characterizations by FE-SEM, TEM, DSC and TGA were performed to investigate their morphology, structure, thermal storage and decomposition behavior, respectively. Experimental results reveal that the fabricated PCFs are randomly arranged and show a good cylindrical structure with fiber diameters ranging from tens to hundreds of nanometers. Most of the HPCMEs are well encapsulated by PMIA sheaths and appear as isolated segments or elongated channels inside the fiber. Given their proper phase change span (30-40°C), considerable enthalpies, good shape stability and greatly enhanced thermal resistance, the prepared HPCMEs/PMIA PCFs are expected to have wide prospects in thermo-regulating protective clothing and other fields related to thermal energy storage.  相似文献   

15.
Membranes with high water permeation capability as well as high rejection to dye molecules are very important for dye separation. In this study, a metal organic framework structure (Cu-BTC) was fabricated in situ on a poly(vinyl difluoride) hollow fiber support for nanofiltration of dye solution. In order to protect the Cu-BTC layer, the surface was coated by crosslinking polyvinyl alcohol. The composite membranes showed no rejection to divalent salts and high rejection to Congo Red dye. It was noticed that several Cu-BTC layers could enhance dye rejection of the composite membranes. This novel composite membrane showed promising applications in the separation of dye molecules from aqueous solutions containing dissolved salts.  相似文献   

16.
In this study, two biodegradable polymers, polycaprolactone (PCL) and polyvinyl alcohol (PVA) were used to fabricate nanofiber nonwovens (NFNs). Also, the silver nanoparticles (AgNPs) successfully reduced by using tea polyphenols (TP) and incorporated in the NFNs via electrospinning. The morphologies of the NFNs and AgNPs were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), respectively. The PCL nanofibers and PVA nanofibers interweaved each other, and AgNPs with average diameter 1.53±0.15 nm were embedded in the PVA nanofibers. The properties of electrospun NFNs were characterized by pore property, swelling/weight loss, water contact angle, mechanical property, and antibacterial activity. The nanofibers cross-linked to each other forming the 3Dnetwork porous structure with diameter about 1-1.5 μm. Although the hydrophobic PCL was added in the hybrid NFNs, the NFNs still showed hydrophilic propriety, high swelling degree (i.e. swelling degree is 330 % for 48 h), and low weight loss (i.e. weight loss is 22.4 % for 48 h). Also, the hybrid PCL/PVA/AgNPs NFNs exhibited a suitable mechanical property for wound dressings (i.e. tensile strength is 4.27 MPa, and breaking elongation is 88 %). Moreover, the hybrid NFNs effectively inhibited growth of Escherichia coli and Staphylococcus aureus. In summary, this PCL/PVA/AgNPs NFNs may provide a promising candidate for accelerating wound healing.  相似文献   

17.
Two different electrospinning processes (traditional single fluid one and a modified coaxial electrospinning with organic solvent as sheath fluid) are investigated in relation to their capability of producing thinner nanofibers. Both the modified coaxial electrospinning and single fluid electrospinning can produce thinner nanofibers with polyvinylpyrrolidone (PVP) as a polymer model and using a poor volatile solvent N, N-dimethylacetamide (DMAc) in different ways. However the traditional single fluid process was less effective compared to the modified coaxial process, as it suffered more from the limitation of polymer chain entanglement threshold for maintaining structural uniformity of nanofibers. Using DMAc as sheath fluid in the modified process facilitated formation of thinner nanofibers without sacrificing their quality. The mechanism should be that an appropriate DMAc surrounding to the core polymer jet helps to retain it in a fluid state to experience a longer time electrical drawing, with little adverse influence on the polymer chain entanglements. Nanofiber diameters could also be tailored in a linear manner using the modified coaxial process simply through manipulating the sheath solvent flow rates. The modified coaxial process described here extends the capability of electrospinning process and opens a new way to obtain thinner nanofibers with fine structural uniformity.  相似文献   

18.
Polystyrene (PS) composites with nanofibrous structure consisting of multi-walled carbon nanotubes (MWCNTs) with 0-10 wt.% of nanofiller have been fabricated via electrospinning technique. The surface morphology and thermal properties of the composites were evaluated by scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA). The SEM analysis of the composite nanofibers samples revealed that the average diameter of the nanofibers increases with increasing MWCNTs content. The resultant MWCNTs/PS composite nanofibers diameters were in the range of 391±63 to 586±132 nm. The thermal stability of composites was increased after addition of MWCNTs to PS matrix. The electrical conductivity of the composites with different weight percentage of MWCNTs was investigated at room temperature. Electrical conductivity of MWCNTs/PS composite nanofiber followed percolation theory having a percolation threshold V c= 0.45 vol% (~0.75 wt. %) and critical exponent q=1.21. The electrical conductivity and thermal properties confirmed the presence of good dispersion and alignment MWCNTs encapsulated within the electrospun nanofibers. The electromagnetic interference (EMI) shielding effectiveness of the MWCNTs/PS composites was examined in the measurement frequency range of 8.2-12.4 GHz (X-band). The total EMI shielding efficiency of MWCNTs/PS composite nanofibers increased up to 32 dB. The EMI shielding results for MWCNTs/PS composite nanofibers showed that absorption loss was the major shielding mechanism and reflection was the secondary mechanism. The present study has shown the possibility of utilizing MWCNTs/PS composite nanofibers as EMI shielding/absorption materials.  相似文献   

19.
In this study, the morphology and crystal polymorphism of electrospun blend nanocomposite of graphene filled-polyvinylidene fluoride (PVDF)/poly(methyl methacrylate) (PMMA) nanofibers were investigated. The preparation of the nanofibers was carried out by synthesis of PMMA/graphene as a masterbatch through in-situ polymerization, and then followed by compounding with PVDF solution in the different ratios. The process of electrospinning was done at three selective conditions of temperature, moist and ordinary environment. Crystallinity, morphology and thermal properties of nanofibers were characterized by X-ray diffraction spectroscopy (XRD), differential scanning calorimetric (DSC), Transmittance Electron Microscopy (TEM), Thermogravimetric Analyses (TGA), and Field Emission Scanning Electron Microscopic (FE-SEM). The enhancement of β crystal formation in the electrospun graphene-filled blend nanofibers was confirmed by XRD and DSC results. This can be ascribed by the benefits of solution casting, mechanical stretching, high electric field, PMMA interactions and graphene restrictions, altogether in one simple process. Also, presence of water molecules during the electrospinning causes the orientation of fluorine atoms in PVDF due to polar-polar interactions which enhance the polar conformation even in the pure PVDF nanofibers.  相似文献   

20.
Polyglycolic acid-poly lactic glycolic acid (PGA-PLGA) electrospun nanofibers containing silver nanoparticles have been produced and twisted into the nanofibrous yarn. The morphology of nanofibers and produced yarns, as well as the mechanical properties of the yarns, were investigated. Furthermore, in vitro antibacterial properties and in vitro degradation behavior of yarns containing various silver nanoparticles were studied. SEM images confirmed that the addition of the silver nanoparticles into the polymer solution increases the fiber diameters. The result of the mechanical test of the yarns alone and used in two different forms of the knots was measured and results showed that the strength of the yarns without the knot was significantly more than that of others. The biodegradability test showed that the mechanical properties and the weight of the yarns were quickly reduced after subjecting to in vitro condition. The result of the antibacterial test indicated that the nanofiber yarns containing %3 silver nanoparticles were the most appropriate sample with a considerably antibacterial activity against both gram-positive bacterium Staphylococcus aureus and gram-negative bacterium Escherichia Coli with inhibition zones of 8.1 and 9.5 mm, respectively; which demonstrated that silver nanoparticles retained their effectiveness after the electrospinning process. Therefore the nanofibrous yarns containing silver nanoparticles could be successfully produced by the electrospinning process with the proper antibacterial property as a candidate for the surgical sutures.  相似文献   

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