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Electrospinning
Terms modified by Electrospinning Selected AbstractsElectrospinning of Manmade and Biopolymer Nanofibers,Progress in Techniques, Materials, and ApplicationsADVANCED FUNCTIONAL MATERIALS, Issue 18 2009Seema Agarwal Abstract Electrospinning of nanofibers has developed quickly from a laboratory curiosity to a highly versatile method for the preparation of a wide variety of nanofibers, which are of interest from a fundamental as well as a technical point of view. A wide variety of materials has been processed into individual nanofibers or nanofiber mats with very different morphologies. The diverse properties of these nanofibers, based on different physical, chemical, or biological behavior, mean they are of interest for different applications ranging from filtration, antibacterial coatings, drug release formulations, tissue engineering, living membranes, sensors, and so on. A particular advantage of electrospinning is that numerous non-fiber forming materials can be immobilized by electrospinning in nanofiber nonwovens, even very sensitive biological objects such as virus, bacteria, and cells. The progress made during the last few years in the field of electrospinning is fascinating and is highlighted in this Feature Article, with particular emphasis on results obtained in the authors' research units. Specific areas of importance for the future of electrospinning, and which may open up novel applications, are also highlighted. [source] Progress in the Field of Electrospinning for Tissue Engineering ApplicationsADVANCED MATERIALS, Issue 32-33 2009Seema Agarwal Abstract Electrospinning is an extremely promising method for the preparation of tissue engineering (TE) scaffolds. This technique provides nonwovens resembling in their fibrillar structures those of the extracellular matrix (ECM), and offering large surface areas, ease of functionalization for various purposes, and controllable mechanical properties. The recent developments toward large-scale productions combined with the simplicity of the process render this technique very attractive. Progress concerning the use of electrospinning for TE applications has advanced impressively. Different groups have tackled the problem of electrospinning for TE applications from different angles. Nowadays, electrospinning of the majority of biodegradable and biocompatible polymers, either synthetic or natural, for TE applications is straightforward. Different issues, such as cell penetration, incorporation of growth and differentiating factors, toxicity of solvents used, productivity, functional gradient, etc. are main points of current considerations. The progress in the use of electrospinning for TE applications is highlighted in this article with focus on major problems encountered and on various solutions available until now. [source] Electrospinning of Diphenylalanine Nanotubes,ADVANCED MATERIALS, Issue 12 2008Gurvinder Singh Electrospinning from concentrated diphenylalanine solutions in a low-boiling-point solvent results in tubes that are chemically identical to self-assembled tubes, but show different morphologies, especially extreme lengths. Electrospinning of tubes offers more possibilities for manipulation, for example, bridging electrodes in parallel orientation, a possible patterning strategy for electrospun material. [source] Fabrication of Aligned Fibrous Arrays by Magnetic Electrospinning,ADVANCED MATERIALS, Issue 21 2007D. Yang Electrospinning magnetic-nanoparticle-doped polymers under the influence of a magnetic field produces aligned arrays of fibers over large areas (see figure). These nanofibers can be transferred onto the surfaces of other substrates. They can also be stacked into multilayer grids. [source] Production of Submicrometer Diameter Fibers by Two-Fluid Electrospinning,ADVANCED MATERIALS, Issue 17 2004H. Yu Electrospinning of nanofibers of materials that are difficult to process using conventional techniques is reported. Two fluids are electrospun (see Figure) into fibers with core/shell morphology. The "electrospinnable" shell fluid serves as a process aid to electrospin the core fluid. Three examples are illustrated: production of fibers with diameters less than 100 nm, fibers formed of low-molecular-weight polyaniline, and non-blended electrospun silk fibers. [source] The influence of electrospinning parameters on the structural morphology and diameter of electrospun nanofibersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Valencia Jacobs Abstract Electrospinning is a simple method of producing nanofibers by introducing electric field into the polymer solutions. We report an experimental investigation on the influence of processing parameters and solution properties on the structural morphology and average fiber diameter of electrospun poly ethylene oxide (PEO) polymer solution. Experimental trials have been conducted to investigate the effect of solution parameters, such as concentration, molecular weight, addition of polyelectrolyte in PEO solution, solvent effect, as well as governing parameter, such as applied voltage. The concentration of the aqueous PEO solution has shown noteworthy influence on the fiber diameter and structural morphology of electrospun nanofibers. At lower concentrations of PEO polymer solution, the fibers showed irregular morphology with large variations in fiber diameter, whereas at higher concentrations, the nanofibers with regular morphology and on average uniform fiber diameter were obtained. We find that the addition of polyelectrolytes, such as sodium salt of Poly acrylic acid (PAA) and Poly allylamine hydrochloride (PAH), increases the conductivity of PEO solutions and thereby decreases the bead formation in electrospun nanofibers. The increase in applied voltage has been found to affect the structural morphology of nanofiber while the addition of ethanol in PEO solution diminishes the bead defects. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Electrospinning of degradable elastomeric nanofibers with various morphology and their interaction with human fibroblastsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Erik Borg Abstract Artelon® (degradable poly(urethane urea) elastomer) was electrospun into scaffolds for tissue engineering. The diameter of the electrospun fibers, studied by scanning electron microscopy, ranged from 100 nm to a few ,m, with an average diameter of 750 nm. The molar mass of the polymer had a major influence on the morphology of the scaffold. Furthermore, aging of the polymer solution caused changes in viscosity, as measured by stress sweeps between 13.5,942 Pa that affected the morphology. The electrospun Artelon mats exhibited about the same elongations to break, both exceeding 200%, measured by tensile tests. The degradation study showed similar degradation behavior in electrospun mats and solids. In vitro study showed that human fibroblasts not only adhere to the surface but also migrate, proliferate, and produce components of an extracellular matrix. These results strongly support the use of electrospun Artelon as a scaffold in tissue engineering. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Electrospinning of cellulose-based nanofibersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2007Audrey Frenot Abstract Cellulose derivatives of carboxymethyl cellulose sodium salt (CMC), hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), and enzymatically treated cellulose have been electrospun, and the microstructure of the resulting nanofibers has been analyzed by scanning electron microscopy (SEM). Before electrospinning, the solutions were characterized by viscometry and surface tension measurements, and the results were correlated with spinnability. Four different CMC derivatives, varying in molecular weight (Mw), degree of substitution (DS), and substitution pattern, have been electrospun in mixtures with poly(ethylene oxide) (PEO), and nanofibers of various characteristics have formed. The CMC-based nanostructures, i.e., the nonwoven sheet and individual nanofibers, proved to be independent of Mw and DS but largely dependent on the substitution pattern. The nonwoven sheets varied in homogeneity, and beads appeared on the individual fibers. Depending on the chemical nature of the CMC, the extraction of PEO resulted in pure CMC nanostructures of varying appearance, indicating that the distribution of PEO and CMC in the nanofibers also varied. Two different HPMC derivatives, varying in DS, were electrospun into nanofibers. Homogeneous nonwoven sheets based on nanofibers of similar appearance are formed, independent of the substitution content of the HPMC sample. Preliminary fibers were obtained from enzymatically treated cellulose in a solvent system based on lithium chloride dissolved in dimethyl acetamide (LiCl: DMAc). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1473,1482, 2007 [source] Electrospinning and crosslinking of zein nanofiber matsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007Chen Yao Abstract Electrospinning processing can be applied to fabricate fibrous polymer mats composed of fibers whose diameters range from several microns down to 100 nm or less. In this article, we describe how electrospinning was used to produce zein nanofiber mats and combined with crosslinking to improve the mechanical properties of the as-spun mats. Aqueous ethanol solutions of zein were electrospun, and nanoparticles, nanofiber mats, or ribbonlike nanofiber mats were obtained. The effects of the electrospinning solvent and zein concentration on the morphology of the as-spun nanofiber mats were investigated by scanning electron microscopy. The results showed that the morphologies of the electrospun products exhibited a zein-dependent concentration. Optimizing conditions for zein produced nanofibers with a diameter of about 500 nm with fewer beads or ribbonlike nanofibers with a diameter of approximately 1,6 ,m. Zein nanofiber mats were crosslinked by hexamethylene diisocyanate (HDI). The tensile strength of the crosslinked electrospun zein nanofiber mats was increased significantly. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:380,385, 2007 [source] Superhydrophobic Mats of Polymer-Derived Ceramic FibersJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2008Sourangsu Sarkar Solid preceramic polyaluminasilazane was synthesized through the reaction between liquid cyclosilazane and aluminum tri-sec-butoxide at 160°C. Electrospinning of polyaluminasilazane/polyethyleneoxide (1/0.0001 mass ratio) in chloroform solutions generated smooth fibers while the electrospun fibers from the chloroform/N,N -dimethylformamide solutions had submicrometer structures on the fiber surfaces. Smooth and rough SiCNO ceramic fibers were obtained by the pyrolysis of the green fibers with an 80% yield. Superhydrophobic mats of ceramic fibers were fabricated via a chemical vapor deposition of perfluorosilane onto the rough fibers. These superhydrophobic mats possess good chemical and thermal stability. [source] Phase Morphology in Electrospun Zirconia MicrofibersJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2008Erin Davies Electrospinning of sol,gels has been used to produce zirconium-doped polymer microfibers from zirconyl chloride and poly(vinylpyrollidone) precursors. Calcination of these structures between temperatures of 370° and 930°C resulted in the formation of zirconia nanograined microfibers whose diameters ranged from 1200 to 800 nm at the higher temperatures and whose average grain size ranged from 9 to 33 nm. X-ray diffraction analysis revealed varying amounts of monoclinic and tetragonal zirconia present in the fibers and established how this varied with calcination temperature and time. The tetragonal phase was shown to be unstable and disappeared on heating the material beyond around 750°C. The amount of zirconia yielded from the precursor material was measured and was found to be consistently greater than the theoretical yield. Average grain size within the microfibers increased with increasing calcination temperature and is effectively doubled when a 10 kPa pressure was applied. The effect of pressure also results in the creation of new crystal structures within the nanofibers and, as with traditional zirconia processing, the addition of impurity ions was found to stabilize the tetragonal phase. [source] The Influence of Solvent Properties and Functionality on the Electrospinnability of Polystyrene NanofibersMACROMOLECULAR MATERIALS & ENGINEERING, Issue 7 2006Cattaleeya Pattamaprom Abstract Summary: In order to produce nanometer-sized fibers at an industrial scale, not only the morphology but also the production rate of fibers is important. The effect of solvent properties and functionality on the production rate of electrospun PS nanofibers was investigated using eighteen different solvents. The solution concentration was varied between 10 and 30% w/v. Electrospinning of PS solutions was carried out at various applied voltages and tip-to-collector distances The production rate of the obtained PS nanofibers was quantified in terms of electrospinnability. We found that the chance for the resulting PS solution to be spinnable is greater for solvents with high dipole moment and low viscosity. The solvent that provided the highest electrospinnability for polystyrene was DMF and the functionalities that promoted high dipole moment and thus high spinnability were the carbonyl group and the nitrogen group with free electrons. General guidelines for choosing suitable solvents for successful production of electrospun nanofibers have also been proposed. SEM image of PS 685D at 200× magnification and the %-coverage of the fibers obtained by using DMF, chloroform, and 1,4-dioxane. [source] Electrospinning of Collagen Nanofiber Scaffolds from Benign SolventsMACROMOLECULAR RAPID COMMUNICATIONS, Issue 7 2009Bin Dong Abstract Nanofiber scaffolds of collagen have been fabricated via electrospinning using benign solvent systems as a replacement for 1,1,1,3,3,3 hexafluoro-2-propanol. Simple binary mixtures of phosphate-buffered saline and ethanol have been found to be highly effective for electrospinning. FTIR spectra suggest that the triple helical structure of collagen was conserved after dissolution and electrospinning. Crosslinking of the electrospun collagen scaffolds was achieved with standard methods. [source] "Barbed nanowires" from polymers via electrospinningPOLYMER ENGINEERING & SCIENCE, Issue 1 2009Andreas Holzmeister Electrospinning is a highly versatile technique that allows producing fibers with diameters down to a few nanometers not only from polymers but also from metals, metal oxides, or ceramics. Fiber formation in electrospinning differs strongly from other fiber producing methods such as extrusion in that it is basically governed by self-assembly processes induced by specific electrostatic interactions following the Earnshaw theorem of electrostatics. This allows the production of nanofibers with very peculiar shapes. Here, we report the one step fabrication of barbed nanofibers due to a particular choice of the spinning conditions. Such barbed fibers allow, among others, to control the total porosity of nanofiber nonwovens and to reduce the tendency of linear nano-objects towards aggregation. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers [source] Electrospinning and alignment of polyaniline-based nanowires and nanotubes,POLYMER ENGINEERING & SCIENCE, Issue 9 2008A. Attout Polyaniline (PANi) nanowires and nanotubes are processed by electrospinning. Nanowires are electrospinned using PANi/PEO and PANi/PMMA polymer blends. The morphology and composition of these nanofibers are determined by scanning electron microscopy (SEM) and Nano-Secondary Ion Mass Spectrometry (Nano-SIMS). The conductive polymer seems more homogeneously distributed for the PANi/PEO than for the PANi/PMMA blend nanowires, which exhibit a phase separation. On the other hand, pure PANi nanotubes are prepared using PMMA nanowires as a template. The synthesis is followed by X-ray photoelectron spectroscopy (XPS), SEM and Nano-SIMS. Moreover, a simple method based on electrostatic steering allows us to align these fibers on a substrate. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers [source] Electrospinning of polyamides with different chain compositions for filtration applicationPOLYMER ENGINEERING & SCIENCE, Issue 6 2008Pirjo Heikkilä Electrospinning of several polyamides, PA6, PA66, PA612, PA614, PA1012, and PA1014, having different chain compositions and lengths of diacid and diamine segments, was demonstrated. Electrospinnability and fiber production rate of these polyamides were evaluated. Electrospun fibers were characterized with regard to their use in air filtration by measuring fiber diameter and filtration efficiency of fiber coating. Longer nonpolar chain segments of higher polyamides could in theory indicate higher dielectricity compared to PA6 and PA66, which would be an advantage in filtration applications. The solubility in polar formic acid and electrospinnability of higher polyamides, on the other hand, were clearly impaired with increased length of chain segments. Hence, PA66 is our best choice, and PA612 and PA6 our second options for commercial filtration applications if fiber electrospinnability, production rate, fiber diameter, and its distribution are concerned. Filtration efficiency of more than 95% of the particles having a diameter of 0.16 ,m and above was achieved with 0.5 g/m2 coating of PA66 nanofibers. Further increase in coating weight mainly increased the pressure drop to an unusable range without a significant further improvement of filtration efficiency. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers. [source] Electric current as a control variable in the electrospinning processPOLYMER ENGINEERING & SCIENCE, Issue 7 2006Ravikant Samatham In the electrospinning process submicron-diameter polymer fibers can be produced when a high potential difference is applied to a polymer drop suspended at the tip of a capillary. The electrospinning process is affected by a wide range of parameters, because of which controlling the properties of the fibers is difficult. This is the major hurdle in the development of practical applications of electrospun fibers along with its low productivity. Here we are proposing to use the electric current in the electrospinning process to control the "quality of the fibers". Electrospinning of a solution of polyacrylonitrile in dimethylformamide (PAN/DMF) was done by applying a programmed variable flow rate at different constant voltages. The electric current in the process was measured in real time. Four types of jet regimes were observed, electric current and the morphology of the fibers corresponding to these regimes were analyzed. A relation between the electric current, type of jet and morphology of the fibers has been established. The mechanical properties of electrospun fiber mats were also measured by a tensile testing method. POLYM. ENG. SCI. 46:954,959, 2006. © 2006 Society of Plastics Engineers [source] Co-electrospun composite nanofibers of blends of poly[(amino acid ester)phosphazene] and gelatinPOLYMER INTERNATIONAL, Issue 5 2010Yi-Jun Lin Abstract Electrospinning is known as a simple and effective fabrication method to produce polymeric nanofibers suitable for biomedical applications. Many synthesized and natural polymers have been electrospun and reported in the literature; however, there is little information on the electrospinning of poly[(amino acid ester)phosphazene] and its blends with gelatin. Composite nanofibers were made by co-dissolving poly[(alaninoethyl ester)0.67(glycinoethyl ester)0.33phosphazene] (PAGP) and gelatin in trifluoroethanol and co-electrospinning. The co-electrospun composite nanofibers from different mixing ratios (0, 10, 30, 50, 70 and 90 wt%) of gelatin to PAGP consisted of nanoscale fibers with a mean diameter ranging from approximately 300 nm to 1 µm. An increase in gelatin in the solution resulted in an increase of average fiber diameter. Transmission electron microscopy and energy dispersive X-ray spectrometry measurements showed that gelatin core/PAGP shell nanofibers were formed when the content of gelatin in the hybrid was below 50 wt%, but homogeneous PAGP/gelatin composite nanofibers were obtained as the mixing ratios of gelatin to PAGP were increased up to 70 and 90 wt%. The study suggests that the interaction between gelatin and PAGP could help to stabilize PAGP/gelatin composite fibrous membranes in aqueous medium and improve the hydrophilicity of pure PAGP nanofibers. Copyright © 2009 Society of Chemical Industry [source] Preparation of carbon nanofibres through electrospinning and thermal treatment,POLYMER INTERNATIONAL, Issue 12 2009Cheng-Kun Liu Abstract Electrospinning is a versatile process to obtain continuous carbon nanofibres at low cost. Thermoplastic and thermosetting polymer precursors are utilized to prepare electrospun carbon nanofibres, activated carbon nanofibres through chemical and/or physical activation and functionalized composite carbon nanofibres by surface coating or electrospinning a precursor solution tailored with nanomaterials. Many promising applications of electrospun carbon nanofibres can be expected if appropriate microstructural, mechanical and electrical properties become available. This article provides an in-depth review of the research activities regarding several varieties and performance requirements of precursor nanofibres, polyacrylonitrile-based carbon nanofibres and their functionalized products, and carbon nanofibres from other precursors. Copyright © 2009 Society of Chemical Industry [source] Mass production of nanofibre assemblies by electrostatic spinningPOLYMER INTERNATIONAL, Issue 4 2009Feng-Lei Zhou Abstract Electrospinning is a well-established and intensively investigated methodology, and is currently the only known technique that can fabricate continuous nanofibres. The major challenge associated with electrospinning is its production rate, compared with that of conventional fibre spinning. However, the understanding of the scale-up possibility of the electrospinning process is still in its infancy. Substantial up-scaling of electrospinning may pave the way for applications of nanofibre assemblies (i.e. yarns) not accessible otherwise in conventional textile processes, such as weaving, knitting and braiding. Here we summarize recent advances regarding the enhancement of electrospinning throughput with special emphasis on multiple jets from multi-needles and the free surface of polymer solutions. Copyright © 2009 Society of Chemical Industry [source] Electrospinning: The big world of small fibersPOLYMER INTERNATIONAL, Issue 11 2007Ji-Huan He No abstract is available for this article. [source] Modelling electrospinning of nanofibresPROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2009Tomasz A. Kowalewski Electrospinning is based on so-called bending instability which results in an erratic spiralling motion of the liquid jet as it proceeds towards a collecting electrode, where it is eventually deposited as a mat of micro/nanosized fibres. Most electrospinning models formulated within the slender approximation rely, however, on an inconsistent description of electrostatic interactions which renders them grossly inappropriate whenever the discretization is either too coarse or too fine. The present work aims at proposing a discrete slender model which is numerically consistent (allowing use of arbitrary fine meshes) and remains accurate even for coarse meshes. At the same time, efficient numerical techniques based on hierarchical charge clustering are introduced that drastically decrease computational times. Finally, a versatile boundary value method is implemented to enforce fixed-potential boundary conditions, allowing realistic electrode configurations to be investigated. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] A novel electrospinning target to improve the yield of uniaxially aligned fibersBIOTECHNOLOGY PROGRESS, Issue 4 2009Virgil P. Secasanu Abstract Electrospinning is a useful technique that can generate micro and nanometer-sized fibers. Modification of the electrospinning parameters, such as deposition target geometry, can generate uniaxially aligned fibers for use in diverse applications ranging from tissue engineering to material fabrication. For example, meshes of fibers have been shown to mimic the extracellular matrix networks for use in smooth muscle cell proliferation. Further, aligned fibers can guide neurites to grow along the direction of the fibers. Here we present a novel electrospinning deposition target that combines the benefits of two previously reported electrodes: the standard parallel electrodes and the spinning wheel with a sharpened edge. This new target design significantly improves aligned fiber yield. Specifically, the target consists of two parallel aluminum plates with sharpened edges containing a bifurcating angle of 26°. Electric field computations show a larger probable area of aligned electric field vectors. This new deposition target allows fibers to deposit on a larger cross-sectional area relative to the existing parallel electrode and at least doubles the yield of uniaxially aligned fibers. Further, fiber alignment and morphology are preserved after collection from the deposition target. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Polymer Fibers as Carriers for Homogeneous CatalystsCHEMISTRY - A EUROPEAN JOURNAL, Issue 21 2007Michael Stasiak Abstract This paper describes a polymer fiber-based approach for the immobilization of homogeneous catalysts. The goal is to generate products that are free of catalysts which would be of great importance for the development of optoelectronic or pharmaceutical compounds. Electrospinning was employed to prepare the non-woven fiber assembly composed of polystyrene. The homogeneous catalyst scandium triflate was immobilized on the polystyrene fibers during electrospinning and on corresponding core shell fibers using a fiber template approach. An imino aldol and an aza-Diels,Alder model reaction were carried out with each fibrous catalytic system. This resulted in the immobilization of homogeneous catalysts in a polymer environment without loss of their catalytic activity and may even be enhanced when compared with reactions carried out in homogeneous solutions. [source] Electrospun Silk Fibroin Mats for Tissue EngineeringENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 3 2008A. Alessandrino Abstract Processing Silk Fibroin (SF) with electrospinning (ES) offers a very attractive opportunity for producing a variety of 2D and 3D matrices with great potential for tissue regeneration and repair due to the superior biocompatibility and mechanical properties of SF. Different combinations of ES parameters were explored to investigate the best experimental set-up related to the dimension and uniformity of the fibers in the electrospun silk fibroin (ES-SF) mats. Using SEM it was found that the ES-SF mats contain uniform fibers with a diameter in the nanometric range obtained by electrospinning a 7.5,% w/v SF solution in formic acid, with an electric field of 2.4,kV/cm and a spinneret-collector distance of 10,cm. FT-IR and DSC analyses were performed to investigate the structure of the ES-SF mats before and after immersion in methanol for different times (5, 10, and 15,min). The methanol treatment was able to promote the crystallization of SF by conformational transition of random coil and other poorly ordered conformations (turns and bends) to the ,-sheet structure. The degree of crystallinity was enhanced as shown by the trend of both the FT-IR crystallinity index and the melting/decomposition peak temperature (from DSC). To study the cytocompatibility of ES-SF mats, tests with L929 murine fibroblasts were carried out. Samples were seeded with the cells and incubated for 1, 3, and 7,days at 37,°C. At each time point, SEM investigations and Alamar blue tests were performed. The SEM images showed cell adhesion and proliferation just after 1,day and cell confluence at 7,days. Alamar blue test demonstrated that there were very low differences between cell viability on ES-SF mats and the tissue culture plastic control. [source] A Fibronectin Peptide-Coupled Biopolymer Nanofibrous Matrix to Speed Up Initial Cellular EventsADVANCED ENGINEERING MATERIALS, Issue 4 2010Ji-Eun Kim Degradable polymer nanofibers produced by electrospinning are attractive for use in cell culture and tissue repair. However, the hydrophobicity and initial poor cell adhesion of synthetic polymers have limited their use in tissue regeneration. Herein, the surface of a poly(lactide-co-caprolactone) Arg-Gly-Asp sequence of nanofiber was tailored with a fibronectin peptide (FN10), which was designed to retain the central cell-binding domain. The electrospun nanofibers are first treated with an alkaline solution to reveal the carboxyl groups on the surface, which is followed by coupling with an FN10 solution in conjunction with a carbodiimide-based agent. Peptide coupling occurs effectively with saturation within 1,h, and the coupled peptide maintains its stability for several days. The peptide-coupled nanofibers show significant improvements in initial cell adhesion and spreading compared with the untreated one, confirming the role of the FN10 peptide in the initial cell events. This methodology may be useful in tailoring the surface of polymeric nanofibers with biomolecules targeted for specific tissue responses. [source] Electrospinning of Manmade and Biopolymer Nanofibers,Progress in Techniques, Materials, and ApplicationsADVANCED FUNCTIONAL MATERIALS, Issue 18 2009Seema Agarwal Abstract Electrospinning of nanofibers has developed quickly from a laboratory curiosity to a highly versatile method for the preparation of a wide variety of nanofibers, which are of interest from a fundamental as well as a technical point of view. A wide variety of materials has been processed into individual nanofibers or nanofiber mats with very different morphologies. The diverse properties of these nanofibers, based on different physical, chemical, or biological behavior, mean they are of interest for different applications ranging from filtration, antibacterial coatings, drug release formulations, tissue engineering, living membranes, sensors, and so on. A particular advantage of electrospinning is that numerous non-fiber forming materials can be immobilized by electrospinning in nanofiber nonwovens, even very sensitive biological objects such as virus, bacteria, and cells. The progress made during the last few years in the field of electrospinning is fascinating and is highlighted in this Feature Article, with particular emphasis on results obtained in the authors' research units. Specific areas of importance for the future of electrospinning, and which may open up novel applications, are also highlighted. [source] Fluorimetric Nerve Gas Sensing Based on Pyrene Imines Incorporated into Films and Sub-Micrometer FibersADVANCED FUNCTIONAL MATERIALS, Issue 5 2009Jeremy M. Rathfon Abstract The chemical sensing of nerve gas agents has become an increasingly important goal due to the 1995 terrorist attack in a Tokyo subway as well as national security concerns in regard to world affairs. Chemical detection needs to be sensitive and selective while being facile, portable, and timely. In this paper, a sensing approach using a pyrene imine molecule is presented that is fluorimetric in response. The detection of a chloro-Sarin surrogate is measured at 5 ppmv in less than 1 second and is highly selective towards halogenated organophosphates. The pyrene imine molecule is incorporated into polystyrene films as well as micrometer and sub-micrometer fibers. Using both a direct drawing approach and electrospinning, micrometer and nanofibers can be easily manufactured. Applications for functional sensing micrometer and nanofibers are envisioned for optical devices and photonics in addition to solution and airflow sensing devices. [source] Multifunctional Nanobiomaterials for Neural InterfacesADVANCED FUNCTIONAL MATERIALS, Issue 4 2009Mohammad Reza Abidian Abstract Neural electrodes are designed to interface with the nervous system and provide control signals for neural prostheses. However, robust and reliable chronic recording and stimulation remains a challenge for neural electrodes. Here, a novel method for the fabrication of soft, low impedance, high charge density, and controlled releasing nanobiomaterials that can be used for the surface modification of neural microelectrodes to stabilize the electrode/tissue interface is reported. The fabrication process includes electrospinning of anti-inflammatory drug-incorporated biodegradable nanofibers, encapsulation of these nanofibers by an alginate hydrogel layer, followed by electrochemical polymerization of conducting polymers around the electrospun drug-loaded nanofibers to form nanotubes and within the alginate hydrogel scaffold to form cloud-like nanostructures. The three-dimensional conducting polymer nanostructures significantly decrease the electrode impedance and increase the charge capacity density. Dexamethasone release profiles show that the alginate hydrogel coating slows down the release of the drug, significantly reducing the burst effect. These multifunctional materials are expected to be of interest for a variety of electrode/tissue interfaces in biomedical devices. [source] Nanofiber Generation of Gelatin,Hydroxyapatite Biomimetics for Guided Tissue Regeneration,ADVANCED FUNCTIONAL MATERIALS, Issue 12 2005H.-W. Kim Abstract The development of biomimetic bone matrices is one of the major goals in the bone-regeneration and tissue-engineering fields. Nanocomposites consisting of a natural polymer and hydroxyapatite (HA) nanocrystals, which mimic the human bone matrix, are thus regarded as promising bone regenerative materials. Herein, we developed a biomimetic nanocomposite with a novel nanofibrous structure by employing an electrospinning (ES) method. The HA precipitate/gelatin matrix nanocomposites are lyophilized and dissolved in an organic solvent, and then electrospun under controlled conditions. With this process, we can successfully generate a continuous fiber with a diameter of the order of hundreds of nanometers. The internal structure of the nanofiber features a typical nanocomposite, i.e., HA nanocrystals well distributed within a gelatin matrix. These nanocomposite fibers improve the bone-derived cellular activity significantly when compared to the pure gelatin equivalent. This method of generating a nanofiber of the biomimetic nanocomposite was effective in producing a biomedical membrane with a composition gradient, which is potentially applicable in the field of guided tissue regeneration (GTR). [source] | ||||||||||||||||||||||||||||||||||