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Copyright of Industria Textila is the property of Institutul National de Cercetare-Dezvoltare pentru Textile si Pielarie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The appearance of fabric is very important when a customer makes a choice for outer apparel. One of the factors that has an effect on the users’ judgment and on the appearance of the fabric is the luster of textiles. The luster can be considered as one of the most effective and essential factors of investigating the appearance of a fabric that is used by a consumer. In order to determine textile luster, there are different methods based on classic definitions; the ones based on image processing have results closer to human impressions of the fabric. Nevertheless, all the determining methods give numerical luster indexes which are far from the reality of a human’s impression, which is a qualitative one for luster. One method that can be used to transform numerical data to qualitative data is fuzzy logic for the classification of data for the luster index.In the presented method, after indicating luster index by the use of image processing, different fabric samples are classified in six different classes based on the luster determined by judgment of ten different inspectors. The luster index is finally classified in six fuzzy classes based on fuzzy logic theory. Results show that fuzzy classification is confirmed by viewers’ judgments. [ABSTRACT FROM PUBLISHER]

The main objective of this paper was to develop a more advanced finishing treatment for the stitch shape regularity and dimensional properties of knitted fabrics. In our previous work, we presented a novel definition of knitted fabric regularity. In the present study we utilised our pervious approach based on Radon transformation analysis to study the effect of different relaxation regimes on the above properties of plain fabrics. We applied various relaxation methods to plain fabrics to make the stitch shape closer to the ideal. The rhythm of stitch shape improvement was evaluated by measuring the deviation of the direction angle of the stitches against the ideal state. The results show that the average fabric irregularity index after ultrasonic-chemical relaxation treatment is better than other relaxation method indices. Moreover the average fabric constant dimensional parameter (Ks) after the above treatment is higher than values reported by pervious workers. Therefore we propose this relaxation treatment as a new relaxation method that is more effective with respect to plain fabric regularity and stability during usage. [ABSTRACT FROM AUTHOR]

The commingled hybrid yarns of different structures have been used to investigate the variation in their abrasion resistance over those of simple yarns by calculating the abrasion destruction index. The cotton yarns of the counts 20Ne and 30Ne and cotton-polyester yarns of the same counts (20Ne and 30Ne) at 20, 40 and 60 bar pressure, have been commingled using flat and textured polyester yarns of 150 den. The produced samples are then abraded by a standard metallic object at four different stages including 150 abrasion cycles in each stage. Through image analyzing technique, the abrasive damage of the samples has been investigated and the abrasion indexes are calculated. The Kohonen neural network is used to cluster the samples in 5 classes as per their abrasion resistance. The cotton-polyester yarn (30Ne), hybrid samples from cotton (30Ne) and textured polyester at 20, 40 and 60 bar; and the hybrid yarn made from cotton-polyester (30Ne) and flat polyester at 60 bar are found to be the best. Furthermore, the abrasion resistance of samples improves on increasing the pressure of commingling process. Generally, cotton yarn and textured polyester yarn show the better abrasion resistance in comparison with the other samples. [ABSTRACT FROM AUTHOR]

Appearance is an important property of textiles, and in specifying textile appearance luster should be taken into account. There are many problems involved in defining and measuring the luster of textile surfaces, so luster and its measurement have been the subject of extensive investigation, in both theoretical and practical aspects. Many types of surface have been studied and many methods of assessing luster have been devised. There are several devices which are designed to measure luster and gloss, some designed specifically for textiles. However, there is still a lack of information regarding measurement and evaluation of luster of textile surfaces. Current methods investigate fabric via one or more directions and are not capable of providing a general view of fabric luster with regard to appearance, in particular for uneven fabrics. This study reports on a new methodology to obtain an index for the luster of fabric, which compares the luster of fabrics via image analysis. The method produces results consistent with human evaluation of luster, whereas in previous methods the lighting and procedures used in luster calculation have differed from the real-world situations of fabric usage. The method presented in this research, for all samples, takes photographs of fabrics in various directions under constant conditions, and derives the luminance of images. An index is obtained for the luster of fabrics by analyzing the luminance of fabrics. [ABSTRACT FROM AUTHOR]

Fast Fourier Transformation technique has been used to classify the defective points in the yarn surface into three classes, namely less important defective points of textured yarn containing surface fibres and broken filaments; medium defective points; and large and unusual defective points. The results obtained from textured yarn with 300 Nm show that this method can be considered for commonly used yarns in acceptable accuracy. This method can detect the defects in a fraction of seconds and can be installed on machines. [ABSTRACT FROM AUTHOR]

Esophageal stents are used as a clinical method for the treatment of a wide variety of esophageal diseases. Knitted mesh stents have such advantages as high flexibility and ease of production. In this study, an analytical approach was applied to simulate the weft knitted esophageal stents and to investigate the mechanical behavior of these tubular structures against the axial and circumferential stresses by using finite element (FE) and mathematical models. Then, the mechanical properties of the knitted structures were evaluated while the simulated food bolus was passed through the stent channel. The results demonstrated that the FE model had a good performance in simulating the mechanical properties of the esophageal knitted stents. The error of the prediction performance of the FE models was between (10–16)% and (7–11)% for the longitudinal and circumferential directions, respectively. Simulation of the food bolus passage also demonstrated that the esophageal PGA stent wall could tolerate a 7.96 kPa force and a strain of 65% by food bolus; so, it could mimic the real state of esophagus during its application. This model could be applied to design and investigate the mechanical behavior of the knitted stents in clinical application conditions. [ABSTRACT FROM AUTHOR]

Solvent-free polymer electrolytes have been prepared through standard electrospinning and solution casting techniques, respectively. A series of nanofibrous electrolytes with various average fiber diameters and different surface densities were electrospun. In addition, polymeric films were casted with several thicknesses. It was shown that crystalline regions as well as fraction of free lithium ions were enhanced by fabrication of the finer fibers. The solution-casted electrolytes with the higher thicknesses displayed lower free ions and less amorphous phases. The nanofibrous mats illustrated the ionic conductivity from 0.062 to 0.172 mS.cm−1.While, the solution-casted ones presented lower ionic conductance in the range of 0.006 to 0.008 mS.cm−1. As surface density of the nanofibrous and solution-casted mats increased, the bulk resistance was improved. Moreover, it was identified that the prepared solvent-free electrolytes obeyed the Arrhenius behavior. The nanofibrous and solution-casted electrolytes with the highest ionic conductivities showed the highest values for the dielectric parameters. Furthermore, the optimum as-spun membrane illustrated higher specific capacity and Faradic current density compared with the solution-casted one. The results implied that the electrospun membranes are good candidates for solvent-free electrolyte application in the Li-ion batteries. [ABSTRACT FROM AUTHOR]

In this study, multi-layered nanofiber systems consisting of polycaprolactone/chitosan (PCL/CS) polymers loaded with anticancer drugs, methotrexate (MTX) and 5-fluorouracil (5-FU), were designed and produced. The surface morphology of drug-free and drug-loaded samples was investigated by field-emission scanning electron microscopy (FESEM). Fourier transform infrared spectrometry (FTIR) was employed to study the chemical structure of polymers and drugs. The drug release test in neutral and acidic medium (pH 7.4 and pH 4.4) was carried out, and the released drug concentration was measured using UV-spectrophotometry. Moreover, the mechanical properties of single- and multi-layered samples were also studied. The FESEM images indicated the production of uniform and bead-free fibers. FTIR tests confirmed the presence of the drugs in the polymer mixture. The results revealed higher degradation and weight loss percentage in samples with higher CS content due to the hydrophilic nature of CS. Evaluating the drug release behavior of MTX and 5-FU for 624 h revealed that seven-layered structures have prolonged drug release profile and lower burst release rate. The comparison of the release profile of MTX and 5-FU in neutral and acidic environments showed that the rate and amount of release increase with decreasing the pH value. Also, results indicated that the drug release of nanofibers followed Fickian diffusion mechanism and Higuchi model kinetic. • A novel seven-layered structure loaded with two anti-cancer drugs was studied. • Drug release behavior of 5-FU and MTX was evaluated at pH values of 7.4 and 4.4 • Seven-layered structures provide prolonged drug release and a minimum burst release. • The rate and amount of release increase with decreasing the pH value. • The drug release followed Fickian diffusion mechanism and Higuchi model kinetic. [ABSTRACT FROM AUTHOR]

In this study, plasticized electrospun fibers have been designed and fabricated as an electrolyte for lithium-ion batteries using electrospinning method. Polyethylene oxide (PEO) and lithium perchlorate were used as polymer matrix and lithium salt, respectively. Ethylene carbonate and propylene carbonate were applied to investigate the effects of the plasticizer concentration and various EC:PC ratios on the characteristics of the as-spun electrolytes. In addition, the influence of fiber orientation was examined on the ionic conductivity of the nanofibrous electrolytes. Results illustrated that compared with PC, EC can lead to a greater fraction of free ions, lower activation energy (Ea) and so more ionic conductivity. However, the highest room temperature ion conductivity of 0.171 mS·cm−1 was obtained for the as-spun electrolyte containing EC:PC (3:1) mixture. Moreover, with the increase of PC content, cycle stability of the electrospun electrolytes faded significantly. Furthermore, the ionic conductivity reduced from 0.212 to 0.020 mS·cm−1 with increasing of the fiber alignment. The results implied that the proposed nanostructured fibers can be a great candidate as free-solvent polymer electrolytes applicable in lithium-ion batteries. • Synthesis of electrospun membranes applicable as solvent-free electrolyte in lithium ion batteries. • Revealing the effect of plasticizers on the microstructure and electrochemical characteristics of the electrospun fibers. • Evaluating the effect of fiber alignment on ion conductivity of the electrospun membranes. [ABSTRACT FROM AUTHOR]

• The high-performance PU/PPy nanofibrous actuators was fabricated. • The influence of electrolyte specifications on the actuation behavior was studied. • The larger anions markedly increase the magnitude of bending movement of actuator. • The nanofibrous actuator showed a remarkable bending displacement more than 720°. The unique properties of nanofibrous artificial muscles including high specific surface area, high porosity, and flexibility as well as similarity to natural muscle structures make them a promising option for use in advanced technologies. In this study, a polyurethane/polypyrrole (PU/PPy) nanofibrous bending artificial muscle was produced and contribution of important electrolyte specifications including concentration and type and size of ions on the electrochemomechanical performance was evaluated. The bending actuation of the produced muscles increased with the concentration of electrolyte solution and this increase was observed at a higher rate in lower concentrations. It was found that the nature of electrolyte ions is a key determinant of the mechanism of ion exchange with the conductive polymer. The using of larger anions in the anion exchange mechanism results in greater bending movements. For example, using LiTFSI electrolyte solution instead of LiCl, in the same potential range, increased the bending displacement from 31° to more than 250°. Immersing in the 0.1 M LiTFSI electrolyte solution, the produced nanofibrous artificial muscle showed a remarkable bending displacement more than 720° in a cycle potential between -0.8 V and 0.8 V. This amazing actuation performance demonstrates the high potential of the produced electrochemomechanical artificial muscles in practical applications. [ABSTRACT FROM AUTHOR]

Two azo dyes, acid red 1 (AR1) and acid red 18 (AR18), were used alone or in combination with sodium dodecyl sulfate (SDS) for the electropolymerization of a pyrrole monomer. Polypyrrole (PPy) showed higher redox capacity when SDS and AR18 were used simultaneously as dopant agents (PPy/AR18-SDS) than when the conducting polymer was produced in the presence of SDS, AR18, AR1, or an AR1/SDS mixture. Moreover, PPy/AR18-SDS is a self-stabilizing material that exhibits increasing electrochemical activity with the number of oxidation–reduction cycles. A mechanism supported by scanning electron microscopy and X-ray diffraction structural observations was proposed to explain the synergy between the SDS surfactant and the AR18 dye. On the other hand, the Bordeaux red color of PPy/AR18-SDS, which exhibits an optical band gap of 1.9 eV, rapidly changed to orange-yellow and blue colors when films were reduced and oxidized, respectively, by applying linear or step potential ramps. Overall, the results indicate that the synergistic utilization of AR18 and SDS as dopant agents in the same polymerization reaction is a very successful and advantageous strategy for the preparation of PPy films with cutting-edge electrochemical and electrochromic properties. [ABSTRACT FROM AUTHOR]

• The artificial muscle based on PU/PPy-TFSI nanofibers was produced and characterized. • Using TFSI anions as dopant resulted in an excellent electrical conductivity in PU/PPy nanofibers. • A reversible angular displacement of 160° was achieved by nanofibrous artificial muscle. • The produced PU/PPy nanofibrous artificial muscle can be considered as a Faradaic motor. Conductive polymer-based artificial muscles have attracted enormous interest in various fields due to their unique properties such as electroactivity and biocompatibility. In this study, a bending artificial muscle was fabricated by chemical synthesis of polypyrrole (PPy) onto nanofibrous polyurethane (PU) structures using bis(trifluoromethylsulfonyl)imide (TFSI) anions as dopant. First, PU nanofibers were prepared by electrospinning and then coated with a layer of polypyrrole via in-situ polymerization to produce core-shell nanofibers of PU/PPy-TFSI. The actuation performance of the PU/PPy-TFSI nanofibers in 1M LiClO 4 aqueous solution was analyzed based on their cyclic voltammetric, coulo-voltammetric, dynamo-voltammetric, coulo-dynamic and chronopotentiometric responses. FESEM images showed that the surface of all PU nanofibers has been coated with a uniform layer of PPy in the form of semi-spherical nanostructures. Doping using TFSI anions resulted in an excellent electrical conductivity in nanofibers (314.55 S/cm). The examination of electrochemomechanical properties showed that for the produced electroactive nanofibers, reversible oxidation and reduction processes occur under the potential cycle between -0.8 V and 0.5 V. It was demonstrated that during the oxidation and reduction reactions, the dominant volume variation mechanism can be best explained based on the exchange of perchlorate anions, which yields a reversible angular displacement of 160°. However, a weak mechanism involving the absorption of small lithium cations was also observed at low cathodic potentials. The results demonstrated that the produced nanofibrous artificial muscle could be considered as a Faradaic motor, as its bending angle and velocity are completely controlled by the consumed charge and the applied current, respectively. [ABSTRACT FROM AUTHOR]

Over the last decades by appearing nanotechnology electrospinning has been reconsidered as a significant method. However, electrospinning production rate is limited by the rate at which the polymer solution or melt is fed to a single jet. Feeding rate can be increased through implementing a wide range of methods such as multiple nozzle electrospinning. In the present work, an innovative “quilled” drum with a peculiar design was rotated in a PAN polymer solution in an electrical field to optimize energy consumption, uniform nanofiber distribution on the collector, and increase production rate. The produced nanofibers were compared with those produced from modified multi-nozzle and single-nozzle electrospinning methods. The mean diameters of nanofibers produced from the quilled drum was 32% greater than that of single-nozzle and 28% less than multi-nozzle electrospinning. The CV% of thickness of the webs were 7.9, 11.2, and 12.5% for the quilled, single nozzle and multi-nozzle methods, respectively which showed the presented method produced more uniform webs. The production rate of this electrospinning was 60 and 17 times more than single and multi-nozzle methods, respectively. [ABSTRACT FROM AUTHOR]

Nanofibrous membranes used for burn treatment have become widely popular due to their large surface area and high porous structure. In this study, electrospinning was used to fabricate a blended nanofibrous membrane of polyvinylidene pyrolidone (PVP) and gelatin, to use as wound dressing. The physical and mechanical properties of this novel membrane were investigated using SEM, FTIR and tensile tests. Results showed that poor mechanical properties of gelatin, which are preferred in medical applications for curing burns as they allow for antigen activity and skin repair, can be enhanced by adding PVP in the solution. Silver sulfadiazine (AgSD), an antibacterial agent, was also impregnated into the PVP/gelatin nanofibrous structure during electrospinning. The membrane thus fabricated showed antibacterial activities against both the Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. AgSD release behaviour of fabricated samples indicated short-term drug delivery. It was concluded that the proposed drug-loaded membrane can be used as wound dressing, specifically, in treating skin burns. [ABSTRACT FROM AUTHOR]

In this study, the antifungal activity of both fluconazole and ketoconazole was compared. The drugs were loaded into the polycaprolactone (PCL)/polyvinylpyrrolidone (PVP) nanofibrous mats and the effect of the drug-loaded samples on Candida albicans (Ca) were investigated by disc diffusion method. Furthermore, the characterization of nanofibrous mats was performed by field emission scanning electron microscopy, Fourier transform infrared (FT-IR) and contact angle tests. The mean diameter of nanofibres was 656 nm and it decreased with the addition of drugs into the electrospinning solutions, because the viscosity of solutions were decreased while electron conductivity of solutions was increased. With increase in the amount of the drug from 5 to 15%, the hydrophilicity increased. FT-IR revealed both drugs were physically embedded in the nanofibres and confirmed their presence in the composition. In addition, the degradation behaviour of samples was significant due to by the amount and the dissolution of PVP and approximately 40% loss weight occurred after 22 days. In the disc diffusion tests, both drug-loaded samples had antifungal effect on sensitive isolates of Ca, while for resistant of isolate the ketoconazole had more effective than fluconazole. Overall, the study highlights the ability of antifungal drug-loaded PVP/PCL nanofibrous mats as potential wound dressing materials and local delivery systems. [ABSTRACT FROM AUTHOR]

In liver tissue engineering, improving the ability of the scaffold to increase the tendency of cells to grow and proliferate is very important. In this study, new methods for modifying the surface of Polycaprolactone (PCL)/Chitosan (Cs) nanofiber for use in liver tissue engineering have been proposed. Galactosylation of chitosan was performed in three ways. According to the FE-SEM, FTIR, NMR and DSC analysis, presence of galactose in uniform nanofibers confirmed and led to a decrease in crystallinity. The hydrophobicity of the scaffolds by contact angle showed that the scaffold with galactosylated after electrospinning, had the highest contact angle of 82.22 ± 2° compared to raw scaffold with 98.52 ± 4°. According to the results of degradation in PBS, the highest rate of degradation was observed in scaffolds that were galactosylated after electrospinning. By culturing HepG2 cells on and based on the results of SEM and MTT analysis, found that the presence of galactose in the scaffolds significantly increased cell growth and proliferation without any toxicity. The immersion method shows a greater ability to improve the growth of liver cells. Also, using in-situ way due to the roughness created in this method may lead to better results especially for in-vivo tests. [ABSTRACT FROM AUTHOR]

Nano-micro scaffolds are developed for long-term healing tissue engineering like cartilage. The poly 3-hydroxybutyrate (P3HB)-chitosan/silk and P3HB-chitosan-1 wt% multi-walled carbon nanotubes functionalized by COOH (MWNTs)/silk nano-micro scaffolds are fabricated through electrospinning the solution on a knitted silk which is saturated (S) or unsaturated (U) with P3HB as a mediator to enhance the interaction at nano/microinterface. Consuming MWNTs lead to a decrease in fiber diameter, while an increase in specific surface area, tensile strength and bioactivity properties. The saturation condition as well as MWNTs leads to intensification in the hydrophilicity properties. The nanolayer in all scaffolds lead to an increase in tensile strength in comparison with the pure knitted silk. The scaffold containing MWNTs showed slower degradation rate. MWNTs beside the chitosan and silk provide an appropriate environment for attachment and growth of chondrocytes. The P3HB-chitosan-MWNTs/silk (S) nano-microscaffold can be appropriate for a long-term tissue engineering application like cartilage. Unlabelled Image • Nano-micro scaffolds are fabricated through electrospinning the solution on a knitted silk. • Presence of MWNTs leads to an increase in specific surface area, hydrophilicity, tensile strength and bioactivity. • The scaffold containing MWNTs showed optimized degradation rate in nano and micro phase. • Presence of nano layer in all scaffolds led to an increase in tensile strength. • The nano-micro scaffolds provide an appropriate environment for chondrocytes viability. [ABSTRACT FROM AUTHOR]

In this study, response surface methodology (RSM) based on the central composite design (CCD) was used for modelling the electrospinning process of polyacrylic acid (PAA) nanofibres, so as to assess simultaneously the effect of the most important electrospinning parameters (concentration of polymer solution, applied voltage, distance between the nozzle and collector and flow rate of solution) on the diameter of electrospun PAA nanofibres. The surface morphology was studied by scanning electron microscopy (SEM). The average diameter of PAA nanofibres obtained was from 233 to 1210 nm from SEM images with different process parameters. The results showed that the solution concentration, the applied voltage and the distance between the nozzle and collector are, in that order, the most important parameters affecting the diameter of nanofibres. The flow rate, however, showed no significant effect on the nanofiber diameter. The RSM model predicted that under optimal electrospinning conditions (solution concentration of 3 w/v%, voltage of 16 kV, electrospinning distance of 15 cm and flow rate of 1.75 ml h–1), the nanofibres would be 262 nm in diameter, which was proved to be very close to the actual measured value. Therefore, the obtained results demonstrated the good performance of the RSM model in investigating the effect of electrospinning variables and predicting the diameter of PAA nanofibres. PAA nanofibres have great potential in applications such as sensors and biosensors, removal of heavy metals and contaminants, muscle tissue engineering, etc. and the use of thinner nanofibres leads to their improved performance in these applications. [ABSTRACT FROM AUTHOR]

Herein, poly(caprolactone)/poly (glycerol sebacate) (PCL/PGS) fibrous structures incorporating hydroxyapatite (HA) and graphene oxide (GO) nanofillers were prepared through two procedures, including electrospinning and simultaneous electrospinning/electrospray procedures. Accordingly, introducing nanofillers into the structures through the simultaneous method led to improving the mechanical strength from 3.69 to 4.95 MPa. The electrospray nanofillers caused improvement of the amorphous regions (up to 83.4%) and increased the degradation rate. Furthermore, the filler-filled electrospun/electrospray sample illustrated the highest cell viability of 94.81 ± 0.5%. The results implied that the simultaneous procedure is promising for fabricating filler-loaded membranes as bone tissue scaffolds. [ABSTRACT FROM AUTHOR]

In this research, a new method is used for grading of yarn appearance based on yam images of ASTM standard (section D 2255), by using an image processing technique and an artificial intelligence technique. In this method, grading of yarn appearance is based on computer vision and analyzing the images of standard pictorial boards of yarn. Therefore this method is very similar to human vision. The logic of the classification by ASTM is considered and then a new definition for classification of yarn appearance grade is presented. In this method of classification, the grading procedure is not dependent on yarn structure and raw materials. Thus it is possible to use this method for grading of any type of yarn based on apparent features. [ABSTRACT FROM AUTHOR]

Materials and fabrication methods significantly influence the scaffold's final features in tissue engineering. This study aimed to blend zein with polyhydroxybutyrate (PHB) at 5, 10, and 15 wt%, fabricate scaffolds using electrospinning, and then characterize them. SEM and mechanical analyses identified the scaffold with 10 wt% zein (PHB-10Z) as the optimal sample. Incorporating 10 wt% zein reduced fiber diameter from 894 ± 122 to 531 ± 42 nm while increasing ultimate tensile strength and elongation at break by approximately 53 % and 70 %, respectively. FTIR proved zein's presence in the scaffolds and possible hydrogen bonding with PHB. TGA confirmed the miscibility of polymers. DSC and XRD analyses indicated lower crystallinity for the PHB-10Z than for PHB. AFM evaluation indicated a rougher surface for the PHB-10Z in comparison to PHB. The PHB-10Z demonstrated a more hydrophobic surface and less weight loss after 100 days of degradation in PBS than PHB. The free radical scavenging assay exhibited antioxidant activity for the zein-containing scaffold. Eventually, enhanced cell attachment, viability, and differentiation in the PHB-10Z scaffold drawn from SEM, MTT, ALP activity, and Alizarin red staining of MG-63 cells confirmed that PHB-zein electrospun scaffold is a potent candidate for bone tissue engineering applications. [ABSTRACT FROM AUTHOR]

A novel biodegradable nano/micro hybrid structure was obtained by electrospinning P3HB or PCL nanofibers onto a twisted silk fibroin (SF) structure, with the aim of fabricating a suitable scaffold for tendon and ligament tissue engineering. The electrospinning (ES) processing parameters for P3HB and PCL were optimized on 2D samples, and applied to produce two different nano/micro hybrid constructs (SF/ES-PCL and SF/ES-P3HB). Morphological, chemico-physical and mechanical properties of the novel hybrid scaffolds were evaluated by SEM, ATR FT-IR, DSC, tensile and thermodynamic mechanical tests. The results demonstrated that the nanofibers were tightly wrapped around the silk filaments, and the crystallinity of the SF twisted yarns was not influenced by the presence of the electrospun polymers. The slightly higher mechanical properties of the hybrid constructs confirmed an increase of internal forces due to the interaction between nano and micro components. Cell culture tests with L929 fibroblasts, in the presence of the sample eluates or in direct contact with the hybrid structures, showed no cytotoxic effects and a good level of cytocompatibility of the nano/micro hybrid structures in term of cell viability, particularly at day 1. Cell viability onto the nano/micro hybrid structures decreased from the first to the third day of culture when compared with the control culture plastic, but appeared to be higher when compared with the uncoated SF yarns. Although additional in vitro and in vivo tests are needed, the original fabrication method here described appears promising for scaffolds suitable for tendon and ligament tissue engineering. [ABSTRACT FROM AUTHOR]

[Display omitted] • Design of a simple methodology to tune the color and increase the contrast of polypyrrole (PPy) electrochromic films with dyes. • Establishment of the effect of dopants (dyes and surfactants) on the electrochromic PPy films. • Production of the PPy electrochromic films with high coloration. Three dye molecules (Dye) of Acid Brilliant Scarlet 3R (AR18), Amido Naphthol Red G (AR1), Indigo Carmine (IC), as well as sodium dodecyl sulfate (SDS) as dopant agents were used for electrochemical synthesis of polypyrrole (PPy) layers onto indium doped tin oxide (ITO) coated polyethylene terephthalate (PET) electrode. The morphology, electrochemical, optical, and spectroelectrochemical properties of the layers were investigated. The study of the electrochemical behavior showed that the presence of each AR18, AR1, or IC with SDS, had shown an excellent synergistic effect on the electrochemical stability of layers. The morphological characterization of the PPy/dopant(s) using atomic force microscopy (AFM) showed that the surface roughness in the PPy/IC-SDS layer was 39% and 32% less than the PPy/AR18-SDS and PPy/AR1-SDS, respectively. The absorption spectrum of PPy/dopant(s) in the UV–Vis-NIR wavelength range showed the formation of polaron and bipolaron in PPy chains. Also, the optical bandgap energy of PPy/dopant(s) decreased, and the fully doped state in all PPy films was observed. Spectroelectrochemical properties of the films showed that the simultaneous use of each dye molecule and the surfactant as dopant in PPy layers demonstrated proper electrochemical and optical stability and satisfactory electrochromic parameters. For example, the color contrast of PPy/AR18-SDS was 50%, while this parameter in control sample (PPy doped with lithium perchlorate) was 21%. Also, the cathodic and anodic coloration efficiency showed a 6-fold increase in PPy/Dye-SDS compared to PPy/ClO 4 -. In general, according to the results it is likely that by increasing the number of anion groups in the dye molecules and decreasing their dimensions as dopant agents, the electrochemical and electrochromic properties of the resultant layer would be improved. [ABSTRACT FROM AUTHOR]

Purpose: 5-Fluorouracil (5FU) and Fe 3 O 4 nanoparticles were encapsulated in core-shell polycaprolactone (PCL)/chitosan (CS) nanofibers as a multi-mode anticancer system to study drug release sustainability. The structure of the core-shell drug delivery system was also optimized according to drug release behavior by artificial intelligence. Methods: The core-shell nanofibers were electrospun by a coaxial syringe. Artificial neural network (ANN) was used for function approximation to estimate release parameters. A genetic algorithm was then used for optimizing the structure. Chemical assay of the optimized sample was performed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX). vibration sample magnetometer (VSM) test was conducted to measure the real amount of loaded magnetic nanoparticles. HepG2 cell cytotoxicity was studied and the results for the optimized samples with and without Fe 3 O 4 after 72 hours were reported. Results: Feeding ratio of sheath to core and the amount of CS, Fe 3 O 4 , and 5FU had a statistical effect on nanofibers diameters, which were 300-450 nm. The drug loading efficiency of these nanofibers was 65-86%. ANN estimated the release parameters with an error of 10%. The temperature increased about 5.6°C in the alternative magnetic field (AMF) of 216 kA.m -1 ~300 kHz and 4.8°C in the AMF of 154 kA.m -1 ~400 kHz after 20 minutes. HepG2 cell cytotoxicity for the optimized samples with and without Fe 3 O 4 after 72 hours were 39.7% and 38.8%, respectively. Conclusion: Since this core-shell drug release system was more sustainable compared to the blend structure despite the low half-life of 5FU, it is suggested to utilize it as post-surgical implants for various cancer treatments such as liver or colorectal cancer in the future. This system is capable of providing chemotherapy and hyperthermia simultaneously., (©2022 The Authors.)

In the present work, polyacrylonitrile (PAN) nanofibers reinforced dental composites were investigated to achieve the improved interfacial adhesion between the PAN nanofiber and resin matrix using surface modification of nanofibers. PAN nanofibers mat were prepared by electrospinning and then, surface treated with the activated bisphenol A glycidyl methacrylate (Bis-GMA)/triethyleneglycol dimethacrylate (TEGDMA) (50/50 mass ratio) dental resin followed by photo-curing. Also, the treated nanofibers mat was milled into a powder to achieve the uniform distribution of nanofibers in the matrix resin. The reinforced dental composite were prepared by mixing the various mass fraction of the powder (0.5-15 wt%) with the Bis-GMA/TEGDMA dental monomers. The effect of weight ratio of surface-modified nanofibers to blend resin on the chemical structure, morphology, compression and flexural properties, color and polymerization shrinkage of dental composites was evaluated. The results showed that using surface-treated nanofibers with content of 5 wt% enhanced the compression strength, flexural strength, flexural modulus and work of rupture of the resultant dental composite by factors of 23%, 7%, 80%, and 145%, respectively, comparing to the unreinforced neat resin. Also, the polymerization shrinkage reduces by 37%. These significant improved properties of the dental composite could be due to the semi-interpenetration network formation between surface-modified nanofibers and resin matrix and well distribution of nanofibers in the dental resin. Further increasing the nanofiber content led to poor mechanical properties of obtained dental composites. The results also, revealed that the color of resin composite could be whiter using modified PAN nanofibers as the filler.

As the most important components of a hemodialysis device, nanofibrous membranes enjoy high interconnected porosity and specific surface area as well as excellect permeability. In this study, a tubular nanofibrous membrane of polysulfone nanofibers was produced via electrospinning method to remove urea and creatinine from urine and blood serums of dialysis patients. Nanofibrous membranes were electrospun at a concentration of 11.5 wt% of polysulfone (PS) and dimethylformamide (DMF)/tetrahydrofuran (THF) with a ratio of 70/30. The effects of the rotational speed of collectors, electrospinning duration, and inner diameter of the tubular nanofibrous membrane on the urea and creatinine removal efficiency of the tubular membrane were investigated through the hemodialysis simulation experiments. It was found that the tubular membrane with an inner diameter of 3 mm elecrospun at shorter duration with lower collecting speed had the highest urea and creatinine removal efficiency. The hemodialysis simulation experiment showed that the urea and creatinine removal efficiency of the tubular membrane with a diameter of 3 mm were 90.4 and 100%, respectively. Also, three patients' blood serums were tested with the nanofibrous membrane. The results showed that the creatinine and urea removal rates were 93.2 and 90.3%, respectively.

Scaffolds for tissue engineering (TE) require the consideration of multiple aspects, including polymeric composition and the structure and mechanical properties of the scaffolds, in order to mimic the native extracellular matrix of the tissue. Electrospun fibers are frequently utilized in TE due to their tunable physical, chemical, and mechanical properties and porosity. The mechanical properties of electrospun scaffolds made from specific polymers are highly dependent on the processing parameters, which can therefore be tuned for particular applications. Fiber diameter and orientation along with polymeric composition are the major factors that determine the elastic modulus of electrospun nano- and microfibers. Here we have developed a neural network model to investigate the simultaneous effects of composition, fiber diameter and fiber orientation of electrospun polycaprolactone/gelatin mats on the elastic modulus of the scaffolds under ambient and simulated physiological conditions. The model generated might assist bioengineers to fabricate electrospun scaffolds with defined fiber diameters, orientations and constituents, thereby replicating the mechanical properties of the native target tissue., (Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)