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1.
In recent years, there has been a great demand for artificial materials for biomedical applications, especially to bone growth. In the present study, the in vitro bioactivity of chitosan-acetylated jute blended film was investigated through biomimitic growth of bone-like apatite layer formation in simulated body fluid (SBF) on the surface of the film. Chitosan was prepared from crab shells and the blended film was prepared by solvent casting method using 10 % formic acid aqueous solution of in-house chitosan and mercerized, acetylated jute fiber. Water absorption characteristics (swelling test) and tensile strength (Universal testing machine) of the films were determined. Thermal behavior of the films were examined by TGA analysis. The biocompatibility of the chitosan-acetylated jute (CAJ) film was indicated by the formation of hydroxy apatite (HAp) bone-like layer formed on the surface when soaked in SBF solution for 14 days. The topography of the film was characterized by scanning electron microscope (SEM) and Ca/P ratio of the apatite layer was confirmed to be 50:50 by EDX analysis. The results showed that the CAJ film will be a promising bone substituting material.  相似文献   

2.
The main objective of this work was chemically bioactivation of the conducting polyanizidine (PANIZ) by incorporating a polyester such as polycaprolactone (PCL). Modified PANIZ nanocomposites were synthesized through ring opening and chemical oxidation polymerizations. A four-point probe was applied to measure the conductivity of newly synthesized star-like block copolymer (S-PCL-PANIZ) nanocomposite, which was about 0.44 S cm-1. Conductive biodegradable nanofibers were prepared by electrospinning with 25 and 75 % (wt/wt) S-PCL-PANIZ to PCL. The contact angle of each prepared nanofiber was 87±3°, supporting their usefulness for cell culture. The cultured mouse osteoblast MG63 cells demonstrated normal morphology and significantly higher adhesion and spreading on the nanofiber. The bioactivated PANIZ based nanocomposite may be fruitful in tissue engineering to fabricate conducting biodegradable scaffolds with improved cell adhesion properties for various cell cultures.  相似文献   

3.
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   

4.
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   

5.
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   

6.
Hydrophobic polyvinylpyrrolidone (PVP) nanofibers, which is intensely hygroscopic, has been successfully prepared to improve their moisture resistance using a modified coaxial electrospinning process. A stearic acid (SA) solution was exploited as the sheath fluid to coat the fibers. Scanning electron microscopy demonstrated that the SA-coated PVP nanofibers became increasingly small with a rise in the sheath-to-core flow rate ratio; continuing to increase the sheath flow rate beyond a cut-off point resulted in nanofibres with very complicated morphologies. Transmission electron microscope images showed that SA formed a thin layer on the PVP nanofibers, with SA nanoparticles present on the fiber surfaces when a sheath-to-core flow rate ratio of 0.2:0.8 was used. Attenuated total reflectance-Fourier transform infrared spectroscopy verified the coating of SA onto the PVP nanofibers, and also the formation of hydrogen bonds between the SA and PVP molecules. The SA-coated PVP nanofibers were found to have much enhanced moisture resistance over pure PVP fibers. Modified coaxial electrospinning hence comprises a novel and powerful strategy for nanocoating and surface modification of polymer nanofibers.  相似文献   

7.
The porous Polyvinylidene fluoride (PVDF) nanofibers were prepared by leaching method using polyethylene oxide (PEO) as porogen for the first time. The influences of the molecular weight (MW) and concentration of PEO, and the leaching solution on the morphology and the surface area of the porous PVDF nanofiber were systematically investigated. Polyethylene glycol 6000 (PEG6000) showed a better pore-forming effect. Optimized preparation parameters were obtained. With the ratio of PEG6000/PVDF reaching 1:1, the surface area of the resulting porous PVDF nanofiber was about three times higher than that of the pure PVDF nanofiber. Moreover, NaClO solution as leaching solution showed a very limited influence on the surface area of porous PVDF nanofiber. Afterwards, Ag NPs coated PVDF (Ag/PVDF) nanofiber was prepared by physical adsorption of Ag ions and in-situ reduction reaction using sodium borohydride as reductant. The photoactivity of Ag/PVDF nanofiber was evaluated by the photodegradation of methyl orange (MO) under visible light irradiation. Ag/PVDF nanofiber showed a better photoactivity than PVDF-Ag nanofiber prepared by the ex-situ blending method.  相似文献   

8.
In this study, we developed optimal multifunctional electrospun wound dressings possessing an antibacterial activity and rich in iron, a vital trace element for cell growth. Therefore, synthetic ferric oxide nanoparticles (α-Fe2O3 NPs) were ultrasonically dispersed into preheated gelatin-glycerol solution. A variety of techniques (X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA), in-vitro swelling-degradation studies and antibacterial tests) were used to characterize the electrospun mats. The results highlight that α-Fe2O3 NPs could be successfully dispersed into the electrospun gelatin nanofibers. The electrospun ferric oxide-gelatin-glycerol nanofibrous mats revealed free beads nanofibers with appropriated swelling-degradation behavior. It was observed that addition of α-Fe2O3 NPs enhanced the antibacterial activity of electrospun mats against positive and negative bacteria.  相似文献   

9.
Ployacrylonitrile (PAN) nanofibers were formed by electrospinning. Amidoxime ployacrylonitrile (AOPAN) nanofibers were prepared by reaction with hydroxylamine hydrochloride, which were used as the matrix for metal ions chelation. FTIR spectra of the PAN nanofibers and AOPAN nanofibers were recorded for analysis of the surface chemical structures. The AOPAN conventional fibers were also prepared for comparison, and surface morphologies of the modified PAN conventional fibers and PAN nanofibers were observed by FESEM. Metal ions concentrations were calculated by AAS. The chelated isothermal process and kinetics parameters of the modified PAN nanofibers and PAN conventional fibers were studied in this work. Results indicated that the saturated coordinate capacity of AOPAN nanofibers to Cu2+, Cd2+ was 3.4482 and 4.5408 mmol/g (dry fiber) respectively, nearly two times higher than that of AOPAN conventional fibers. Besides, the desorption rate of Cu2+ and Cd2+ from metal chelated AOPAN nanofibers was 87 and 92 % respectively in 1 mol/l nitric acid solution for 60 min. The isothermal processes were found to be in conformity with Langmuir model.  相似文献   

10.
Application of electrospun nanofibrous scaffolds has received immense attention in tissue engineering. Fabrication of scaffolds with appropriate electrical properties plays a key role in neural tissue engineering. Since fibers orientation in the scaffolds affects the growth and proliferation of the cells, this study aimed to prepare aligned electrospun conductive nanofibers by mixing 1 %, 10 % and 18 % (w/v) doped polyaniline (PANI) with polycaprolactone (PCL)/poly lactic-coglycolic acid (PLGA) (25/75) solution through the electrospinning process. The fibers diameter, hydrophilicity and conductivity were measured. In addition, the shape and proliferation of the nerve cells seeded on fibers were evaluated by MTT cytotoxicity assay and scanning electron microscopy. The results revealed that the conductive nanofibrous scaffolds were appropriate substrates for the attachment and proliferation of nerve cells. The electrical stimulation enhanced neurite outgrowth compared to those PLGA/PCL/PANI scaffolds that were not subjected to electrical stimulation. As polyaniline ratio increases, electric stimulation through nanofibrous PLGA/PCL/PANI scaffolds results in cell proliferation enhancement. However, a raise more than 10 % in polyaniline will result in cell toxicity. It was concluded that conductive scaffolds with appropriate ratio of PANI along with electrical stimulation have potential applications in treatment of spinal cord injuries.  相似文献   

11.
Meta-aramid fibers were dissolved in four different solvent systems (DMAc, DMF, NMP, and DMSO) and two kinds of salts (LiCl and CaCl2) were also introduced in this paper. Meta-aramid fibers had a limited solubility in above four solvents, however, fast dissolution could be obtained after adding a certain amount of salt (LiCl or CaCl2). The concentration of salts was found to be an important role in affecting meltaging, dissolving time and viscosity of electrospun solution. Electrospun meta-aramid nanofibers mats were successfully prepared. A series of characterizations had been carried out by using SEM. The results shows the diameter of meta-aramid nanofibers ranging from 100 to 500 nm. The average diameter of the nanofibers increased with the concentration of meta-aramid fiber solution and the salt solution. A preferable morphology of meta-aramid nanofibers could be obtained under LiCl/DMAc system. While the electrospun nanofibers made in CaCl2/DMAc solvent system had a better performance in thermal stability than that prepared in LiCl/DMAc system. Among the four kinds of prepared nanofibers, the nanofibersmat electrospun in LiCl/DMAc system with a concentration of meta-aramid solution at 11 wt% exhibit the best mechanical properties.  相似文献   

12.
Fabrication of nanofibers with a defined diameter is a primary purpose of the electrospinning process. The diameter of nanofiber is directly related to its individual features, such as mechanical property and porosity. The motivation to conduct the current study was to explore the diameter of hybrid nanofibers of polycaprolactone-gelatin (PCL-GT) as one of the most attractive scaffolds employed in various research fields, such as tissue engineering and industrial fields. We have developed two predictive models describing the electrospinning process of PCL-GT using response surface methodology (RSM) and artificial neural network (ANN). The effect of 4 variables on diameter was analyzed, including total polymer concentration, ratio of PCL to Gel, voltage, and tip-to-collector distance. The individual and interactive effects of the mentioned factors were analyzed using RSM. The total polymer concentration had the most significant individual effect on the diameter of PCL-Gel nanofiber, whereas the other three factors showed less strong individual effects, although, the interactive effects of these factors were more remarkable. It was demonstrated that both models, especially the ANN model, could accurately predict the diameter of PCL-GT nanofiber (regression coefficient > 0.92, mean absolute percentage error < 5.7). The represented predictive models could facilitate construction of electrospun nanofibers from PCL-Gel with wellcontrolled diameter required for any intended purpose.  相似文献   

13.
We report our study on fabrication of soluble eggshell membrane (SESM) and silk fibroin (SF) nanofibers composite (SF/SESM) for facemasks by electrospinning. Biocompatibility of the SF and SESM, determined from hydrophilicity results, is exploited in SF/SESM nanocomposite for facemask application. The SF/SESM nanocomposites were prepared in different ratios of SF and SESM. The samples were characterized by scanning electron microscopy (SEM), FTIR and water droplet adsorption tests conducted via water contact angle (WCA) and water droplet diffusion. The results revealed that addition of SESM has insignificant effect on the electrospinnability of SF nanofibers in the studied ratios. The SEM results depicted regular morphology of the nanofibers except increase in nanofiber diameter with addition of SESM. The FTIR results confirmed respective peaks of SF and SESM in SF/SESM nanocomposite. WCA of the nanofibers decreased with addition of SESM such that for SF/SESM30, 30 % SESM, it reduced to 0 ° from 101 ° for pure SF nanofibers. The research results demonstrate SF/SESM30 nanocomposite as optimum ratio of SF and SESM for facemasks and other biomedical applications.  相似文献   

14.
Phytoncides are volatile organic compounds released from trees and plants and are well known for their natural antibacterial activity. In this study, emulsion electrospinning was used to encapsulate phytoncide in the core of nanofibers, with the aim of developing environmentally friendly, functional nanofibers with a sustained release of the encapsulated component. Core/sheath structured phytoncide/poly(vinyl alcohol) nanofibers were successfully prepared by emulsion electrospinning using an ordinary single-nozzle electrospinning setup. An oil-in-water emulsion of an aqueous solution of poly(vinyl alcohol) (as the aqueous phase) and phytoncide (as the oil phase) was used to prepare the core/sheath structured nanofibers. Nanocomposite fibers were electrospun under various spinning conditions and emulsion formulations to find the suitable processing conditions for fabricating nanofibers with core/sheath structures. The resulting nanofibers exhibited a well-aligned core/sheath structure with fiber diameters of 250-350 nm. The release profile of phytoncide from the core of nanofibers over a 21 day period showed that phytoncide was released in a sustained manner over 14 days. The core/sheath structured phytoncide/poly(vinyl alcohol) nanofibers exhibited 99.9 % bacterial reduction against both Staphylococcus aureus and Escherichia coli, indicating that the encapsulated phytoncide in the fiber provided strong antimicrobial effects.  相似文献   

15.
Electrospinning is a straightforward method to produce sub-micrometer or nanoscale fiber. Polycaprolactone (PCL), an important polymer in biomedical applications, has been electrospun in several solvent systems. N,Ndimethylformamide (DMF) is often used as an additive in the solvent system to prepare PCL nanofibers. The adding of the DMF changes the physical properties of the solution. To trace and understand the influence of these changes on the jet formation as well as the resultant fibers morphologies, a model of jet perturbation based on the Plateau-Rayleigh Instability theory was established to explicate the formation of the particles/fibers and some experiments for testing the solution properties and fibers morphologies were carried out. With the adding of DMF in dichloromethane (DCM)/DMF mixed solvents, the solution surface tensions increase while solution viscosities decrease, which triggers the change of electrospinning to electrospraying in general. However, according to the obtained results, the addition of the DMF makes it easier to induce the transformation of particles electrospraying to fibers electrospinning with smaller diameter. This is attributed to the higher dielectric constant, lower vapor pressure, and higher electric conductivity of DMF. The theoretical model and experimental results strengthen the relations of solution properties, jet moving behaviors, and the resultant fiber morphologies.  相似文献   

16.
Polymer organic-inorganic hybrid nanofibers constitute a new class of materials in which the polymeric nanofibers are reinforced by uniformly dispersed inorganic particles having at least one dimension in nanometer-scale. In the present study, polyacrylonitrile (PAN) and PAN/Na-montmorillonite (PAN/Na-MMT) nanofibers were conducted via electrospinning process. Electrospun PAN and PAN/Na-MMT fibers with the respective mean fiber diameter of about 220 and 160 nm were prepared. The influence of the clay-montmorillonite on the morphology and diameter of nanofibers was investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM) techniques. The microscopic techniques propose that the PAN/Na-MMT composite nanofibers show lower mean fiber diameter than the neat PAN nanofibers. Besides, the difference in nanoclay-content has a slight effect on the distribution of fibers diameter. Thermogravimetric analysis (TGA) results suggest that introduction of clay-nanomaterials improves the thermal characteristics of fibers.  相似文献   

17.
The four binary fatty acid eutectics of capric-lauric acid (CA-LA), capric-myristic acid (CA-MA), capric-palmitic acid (CA-PA), and capric-stearic acid (CA-SA) were firstly prepared as solid-liquid phase change materials (PCMs); then, the composite phase change nanofibers consisting of CA-based binary fatty acid eutectic and polyethylene terephthalate (PET) were fabricated by electrospinning for thermal energy storage. The maximum mass ratios of fatty acid eutectics versus PET in the nanofibers could reach up to 2/1. The FE-SEM images revealed that the composite nanofibers possessed smooth and cylindrical morphological structure having diameters of about 100–300 nm. The fatty acid eutectic could be uniformly distributed in the three-dimension network structure of the PET nanofibers. The FT-IR results indicated that the fatty acid eutectic and PET had no chemical reaction and exhibited good compatibility with each other. The DSC measurements showed that the prepared composite nanofibers had appropriate phase transition temperatures (about 5–38 °C) based upon climatic requirement, whilst the phase change temperatures and the enthalpy values of the composite nanofibers could be adjusted by changing the contents and the types of binary fatty acid eutectics in the nanofibers. The TGA results suggested that the onset thermal degradation temperatures and charred residues at 700 °C of the composite nanofibers were lower than those of pure PET nanofibers, but higher than those of fatty acid eutectic, which were caused by the fact that the PET had better thermal stability than fatty acid eutectic.  相似文献   

18.
In this work, the pure polyacrylonitrile (PAN) nanofibers and PAN/FeCl3 composite nanofibers were prepared by an electrospinning process. Electrospinning solution properties including viscosity, surface tension and conductivity, had been measured and combined with the results of Scanning electron microscopy (SEM), Atomic force microscope (AFM) and Micro Combustion Calorimeter (MCC) to investigate the effects of FeCl3 on the structure, surface morphology and combustion property of electrospun PAN nanofibers, respectively. It was found from SEM images that the diameters of composite nanofibers were decreased with the addition of FeCl3, which was attributed predominantly to the increased conductivity of the polymer solutions compared to viscosity and surface tension. The AFM analyses revealed that the surface morphology of electrospun nanofibers changed from smooth and wrinkle-like structure (without FeCl3) to rough and ridge-like structure (with FeCl3). The results characterized by MCC showed that the loading of FeCl3 decreased the heat release rate (HRR) and improved the combustion property of composite nanofibers.  相似文献   

19.
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   

20.
Drug carrier nanoparticles (NPs) were prepared by the polyelectrolyte method, with chitosan sulfate, with different substituents and quaternary ammonium chitosan, including C236-HACC NPs, C36-HACC NPs, and C6-HACC NPs. To evaluate whether the NPs are suitable for loading different antigens, we chose bovine serum albumin (BSA), ovalbumin (OVA), and myoglobin (Mb) as model antigens to investigate the encapsulation effect of the NPs. The characteristics (size, potential, and encapsulation efficiency) of the NPs were measured. Moreover, the NPs with higher encapsulation efficiency were selected for the immunological activity research. The results showed that chitosan derivative NPs with different substitution sites had different loading effects on the three antigens, and the encapsulation rate of BSA and OVA was significantly better than that of Mb. Moreover, the NPs encapsulated with different antigens have different immune stimulating abilities to DCS cells, the immune effect of OVA-coated NPs was significantly better than that of BSA-coated NPs and blank NPs, especially C236-HACC-OVA NPs. Furthermore, we found that C236-HACC-OVA NPs could increase the phosphorylation level of intracellular proteins to activate cell pathways. Therefore, C236-HACC NPs are more suitable for the loading of antigens similar to the OVA structure.  相似文献   

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