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Electrospinning Technique (electrospinning + technique)
Selected AbstractsFabrication and Drug Delivery of Ultrathin Mesoporous Bioactive Glass Hollow FibersADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Youliang Hong Abstract Ultrathin mesoporous bioactive glass hollow fibers (MBGHFs) fabricated using an electrospinning technique and combined with a phase-separation-induced agent, poly(ethylene oxide) (PEO), are described. The rapid solvent evaporation during electrospinning and the PEO-induced phase separation process demonstrated play vital roles in the formation of ultrathin bioactive glass fibers with hollow cores and mesoporous walls. Immersing the MBGHFs in simulated body fluid rapidly results in the development of a layer of enamel-like apatite mesocrystals at the fiber surfaces and apatite nanocrystals inside the hollow cores. Drug loading and release experiments indicate that the drug loading capacity and drug release behavior of the MBGHFs strongly depends on the fiber length. MBGHFs with fiber length >50,µm can become excellent carriers for drug delivery. The shortening of the fiber length reduces drug loading amounts and accelerates drug release. The MBGHFs reported here with sophisticated structure, high bioactivity, and good drug delivery capability can be a promising scaffold for hard tissue repair and wound healing when organized into 3D macroporous membranes. [source] Preparation, Bioactivity, and Drug Release of Hierarchical Nanoporous Bioactive Glass Ultrathin FibersADVANCED MATERIALS, Issue 6 2010Youliang Hong Hierarchical nanoporous bioactive glass ultrathin fibers with different pore diameters from 1.5-nm micropores up to 65-nm macropores are synthesized using P123,PEO co-templates and an electrospinning technique (see image). Experiments demonstrate that the prepared bioactive glass fibers are highly homogenous and bioactive and their nanopores can control drug release well. [source] GaN Nanofibers based on Electrospinning: Facile Synthesis, Controlled Assembly, Precise Doping, and Application as High Performance UV Photodetector,ADVANCED MATERIALS, Issue 2 2009Hui Wu Nitride nanofibers have been synthesized based on a simple electrospinning technique for the first time. No catalysts or templates are needed in this new synthetic method. Highly oriented GaN nanofiber arrays, as well as a high-performance UV photodetector based on single GaN nanofiber assembled FET devices, can be facilely fabricated using this technique. Precise doping of other elements into the GaN nanofibers is easy by this solution-based synthetic method. [source] Nanofiber generation of hydroxyapatite and fluor-hydroxyapatite bioceramicsJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2006Hae-Won Kim Abstract In this study, we produced hydroxyapatite (HA) and fluor-hydroxyapatite (FHA) bioceramics as a novel geometrical form, the nanoscale fiber, for the biomedical applications. Based on the sol-gel precursors of the apatites, an electrospinning technique was introduced to generate nanoscale fibers. The diameter of the fibers was exploited in the range of a few micrometers to hundreds of nanometers (1.55 ,m,240 nm) by means of adjusting the concentration of the sols. Through the fluoridation of apatite, the solubility of the fiber was tailored and the fluorine ions were well released from the FHA. The HA and FHA nanofibers produced in this study are considered to find potential applications in the biomaterials and tissue engineering fields. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006 [source] A Rapidly Responding Sensor for Methanol Based on Electrospun In2O3,SnO2 NanofibersJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2010Wei Zheng In this paper, we presented a simple and effective electrospinning technique for the preparation of In2O3,SnO2 composite nanofibers. The morphology and chemical structure of the as-prepared samples were analyzed by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results showed that large quantities of In2O3,SnO2 composite nanofibers with diameters from 60 to 100 nm were obtained. The In2O3,SnO2 composite nanofibers exhibited excellent gas sensing properties to methanol, such as fast response/recovery properties, high sensitivity, and good selectivity. [source] Preparation of Zinc Oxide Nanofibers by ElectrospinningJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2006Hui Wu Ultra-thin fibers of zinc oxide (ZnO) were prepared by sol,gel processing and the electrospinning technique using poly(vinyl acetate) and zinc acetate as precursors. The fibers were characterized by thermogravimetric analysis, scanning electron microscopy, Fourier-transfer infrared, and X-ray diffraction, respectively. The results showed that the diameter of the precursor fibers increased with increasing zinc acetate content, and the size of the inorganic ZnO nanofibers decreased obviously as the calcining time increased. [source] Enhanced Mechanical Performance of Self-Bundled Electrospun Fiber Yarns via Post-TreatmentsMACROMOLECULAR RAPID COMMUNICATIONS, Issue 10 2008Xuefen Wang Abstract A new route to high-performance electrospun polymer fibers was developed using a self-bundling electrospinning technique combined with post-treatments such as stretching and annealing under conditions similar to those used for conventional fibers. Self-bundled electrospun PAN fiber yarns were characterized by SEM, mechanical tests, polarized FT-IR spectroscopy and WAXD. The obtained results revealed that the PAN nanofiber yarns possessed enhanced alignment, a higher degree of crystallinity and higher molecular orientation after treatments, resulting in a remarkable improvement in mechanical performance, approaching the strength value of the corresponding conventional fibers. [source] Coaxial electrospinning of PC(shell)/PU(core) composite nanofibers for textile applicationPOLYMER COMPOSITES, Issue 5 2008Xiao-Jian Han To develop a novel functional composite material for textile application, a coaxial electrospinning technique was investigated to electrospin two different polymer solutions into core-shell structured nanofibers in which polyurethane and polycarbonate were used as core and shell materials, respectively. The resultant nanofibers were subsequently characterized by means of scanning electron microscope, transmission electron microscopy, fourier transform infrared spectroscopy, and tensile mechanical test. Furthermore, water vapour transmission rate and pliability of the resulting nonwoven mats were also measured. The preliminary results indicated that it is feasible to attach composite nanofibers, with possible fictionalization on the shell material, onto a substrate fabric. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers [source] Charge storage of electrospun fiber mats of poly(phenylene ether)/polystyrene blendsPOLYMER ENGINEERING & SCIENCE, Issue 12 2009Deliani Lovera Nonwoven fiber mats composed of poly(phenylene ether) (PPE) and polystyrene (PS) blends were prepared by electrospinning of PPE/PS solutions in a mixture of chloroform and hexafluoroisopropanol. The blends showed higher electrospinnability and led to thinner fibers (200 nm,1.3 ,m) than the pure components, because of a proper balance of electrical conductivity and interaction with the electrospinning solvent. The charge retention of the electrospun fibers was evaluated and related to the blend composition and the electret properties of the components. It was found that the nonwoven mats were able to retain up to 60% of the initial surface potential after several days of annealing at temperatures as high as 140°C, which is markedly higher than the charge retention of corona-charged compact films. The capability of the electrospinning technique, to inject charges into the bulk of the material and to orientate the dipoles of the PPE phase in the field direction at the same time, was related to the good surface potential stability of the PPE/PS electrospun fiber mats. The possibility of creating thin PPE/PS fibers with excellent charge retention capabilities makes these materials ideal candidates for electret filter and sensing applications. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers [source] Fabrication of a Novel Hybrid Heart Valve Leaflet for Tissue Engineering: An In Vitro StudyARTIFICIAL ORGANS, Issue 7 2009Hao Hong Abstract The objective of this study was to fabricate biomatrix/polymer hybrid heart valve leaflet scaffolds using an electrospinning technique and seeded by mesenchymal stem cells. Mesenchymal stem cells were obtained from rats. Porcine aortic heart valve leaflets were decellularized, coated with basic fibroblast growth factor/chitosan/poly-4-hydroxybutyrate using an electrospinning technique, reseeded, and cultured over a time period of 14 days. Controls were reseeded and cultured over an equivalent time period. Specimens were examined biochemically, histologically, and mechanically. Recellularization of the hybrid heart valve leaflet scaffolds was significantly improved compared to controls. Biochemical and mechanical analysis revealed a significant increase of cell mass, 4-hydroxyproline, collagen, and strength in the hybrid heart valve leaflets compared to controls. This is the first attempt in tissue-engineered heart valves to fabricate hybrid heart valve leaflets using mesenchymal stem cells combined with a slow release technique and an electrospinning technique. [source] Engineering of Vascular Grafts With Genetically Modified Bone Marrow Mesenchymal Stem Cells on Poly (Propylene Carbonate) GraftARTIFICIAL ORGANS, Issue 12 2006Jun Zhang Abstract:, Bone marrow mesenchymal stem cells (MSCs) have demonstrated their pluripotency to differentiate into different cell lineages and may be an alternative cell source for vascular tissue engineering. The objective of this study is to create small diameter vessels by seeding and culture of genetically modified MSCs onto a synthetic polymer scaffold produced by an electrospinning technique. A tubular scaffold (2 mm in diameter) with a microstructure of nonwoven fibers was produced by electrospinning of poly (propylene carbonate) (PPC). Rat MSCs obtained from bone marrow were expanded in culture and modified with vasculoprotective gene endothelial nitric oxide synthase (eNOS) or marker gene green fluorescent protein (GFP). These MSCs were seeded onto the electrospun fibrous grafts (internal diameter = 2 mm), and cultured in 5% CO2 at 37°C. The growth of MSCs in the scaffold was analyzed with scanning electron microscopy (SEM) and hematoxylin and eosin (H&E) staining. The gene transfer and transgenic gene expression were examined with fluorescence-activated cell sorting (FACS), immunochemical staining, reverse transcriptase-polymerase chain reaction (RT-PCR), and western blot. The production of nitric oxide (NO) by the engineered vessels was measured with an NO detection kit. Our data showed that the seeded cells integrated with the microfibers of the scaffold to form a three-dimensional cellular network, indicating a favorable interaction between this synthetic PPC scaffold with MSCs. High transduction efficiency was obtained with the use of concentrated retrovirus in the gene transfection of MSCs. The eNOS gene transcripts and protein were detected in the grafts seeded with eNOS-modified MSCs by RT-PCR and immunochemical staining. The amount of NO produced by grafts seeded with eNOS-modified MSCs was comparable to that produced by native blood vessels, and it was significantly higher than that in the grafts seeded with nonmodified MSCs. In summary, the vascular graft produced by culture of eNOS gene-modified MSCs onto the electrospun tubular scaffolds shows promising results in terms of function. The use of MSCs and therapeutic genes in tissue engineering of blood vessels could be helpful in improving vessel regeneration and patency. [source] General Strategy for a Large-Scale Fabric with Branched Nanofiber,Nanorod Hierarchical Heterostructure: Controllable Synthesis and ApplicationsCHEMISTRY - A EUROPEAN JOURNAL, Issue 37 2010Meng Shang Abstract The preparation and characterization of a branched nanofiber,nanorod hierarchical heterostructure fabric (TiO2/NiO, TiO2/ZnO, and TiO2/SnO2) are described. The nanomaterial was synthesized on a large scale by an inexpensive, generalizable, facile, and controllable approach by combining the electrospinning technique with a hydrothermal method. The controllable formation process and factors (assistance by hexamethylenetetramine and metal oxide nuclei) influencing the morphology of the branched hierarchical heterostructure are discussed. In addition, photocurrent and photocatalytic studies suggest that the branched hierarchical heterostructure fabric shows higher mobility of charge carriers and enhanced photocatalytic activity relative to a bare TiO2 nanofibrous mat and other heterostructures under irradiation by light. This work demonstrates the possibility of growing branched heterostructure fabrics of various uniform, one-dimensional, functional metal oxide nanorods on a TiO2 nanofibrous mat, which has a tunable morphology by changing the precursor. The study may open a new channel for building hierarchical heterostructure device fabrics with optical and catalytic properties, and allow the realization of a new class of nano-heterostructure devices. [source] In-Situ Encapsulation of Nickel Particles in Electrospun Carbon Nanofibers and the Resultant Electrochemical PerformanceCHEMISTRY - A EUROPEAN JOURNAL, Issue 41 2009Liwen Ji Loaded nanofibers: Ni nanoparticle-loaded carbon nanofibers, which exhibit high reversible lithium-storage capacity, excellent cycling performance, and remarkably enhanced rate capability, are fabricated by using the electrospinning technique and the subsequent stabilization and carbonization processes (see figure). [source] | ||||||||||||||||||||||