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Electrospun Poly (electrospun + poly)
Selected AbstractsDisulfide-Crosslinked Electrospun Poly(, -glutamic acid) Nonwovens as Reduction-Responsive ScaffoldsMACROMOLECULAR BIOSCIENCE, Issue 6 2009Hiroaki Yoshida Abstract Novel water-insoluble, and reduction-responsive nonwoven scaffolds were fabricated from , -PGA and tested in cell culture. An electrospinning method was developed to produce scaffolds of fibers with diameters of 0.05,0.5 µm. Crosslinking of the fibers with cystamine in the presence of EDC resulted in water-insoluble , -PGA nonwovens with disulfide crosslinkages. These crosslinked fibers were easily decomposed under physiological conditions using L -cysteine, a biocompatible reductant. In vitro experiments with mouse L929 fibroblasts showed good adhesion onto , -PGA-SS fiber matrices and excellent cell proliferation. These , -PGA-SS nonwovens can be used as novel biocompatible and biodegradable scaffolds with reduction-responsiveness for biomedical or tissue engineering applications. [source] Structural, Electrical, Mechanical, and Thermal Properties of Electrospun Poly(lactic acid)/Polyaniline Blend FibersMACROMOLECULAR MATERIALS & ENGINEERING, Issue 7 2010Paulo H. S. Picciani Abstract Conducting electrospun fiber mats based on PLA and PAni blends were obtained with average diameter values between 87 and 1 006,nm with PAni quantities from 0 to 5.6 wt.-%. Structural characteristics of fiber mats were compared to cast films with the same amount of PAni and studied by SEM, SAXS, and AFM. Thermal properties of fiber mats and cast films were compared by DSC analyses. Mechanical properties of fiber mats were also evaluated. It was found that electrospinning process governs the crystal structure of the fibers and strongly affects fiber properties. New properties of PLA/PAni blends are reported due to the size fiber reduction. [source] Electrospun poly(L -lactic acid)/hydroxyapatite composite fibrous scaffolds for bone tissue engineering,POLYMER INTERNATIONAL, Issue 2 2010Boontharika Chuenjitkuntaworn Abstract Poly(L -lactic acid) (PLLA) is one of the most studied synthetic biodegradable polymeric materials as a bone graft substitute. Taking into account the osteoconductive property of hydroxyapatite (HAp), we prepared fibrous matrices of PLLA without and with HAp particles in amounts of 0.25 or 0.50% (w/v, based on the volume of the base 15% w/v PLLA solution in 70:30 v/v dichloromethane/tetrahydrofuran). These fibrous matrices were assessed for their potential as substrates for bone cell culture. The presence of HAp in the composite fibre mats was confirmed using energy dispersive X-ray spectroscopy mapping. The average diameters of both neat PLLA and PLLA/HAp fibres, as determined using scanning electron microscopy, ranged between 2.3 and 3.5 µm, with the average spacing between adjacent fibres ranging between 5.7 and 8.5 µm. The porosity of these fibrous membranes was high (ca 97,98%). A direct cytotoxicity evaluation with L929 mouse fibroblasts indicated that the neat PLLA fibre mats released no substance at a level that was toxic to the cells. The presence of HAp particles at 0.50% w/v in the PLLA fibrous scaffolds not only promoted the attachment and the proliferation of MC3T3-E1 mouse pre-osteoblastic cells, but also increased the expression of osteocalcin mRNA and the extent of mineralization after the cells had been cultured on the scaffolds for 14 and 21 days, respectively. The results obtained suggested that the PLLA/HAp fibre mats could be materials of choice for bone tissue engineering. Copyright © 2009 Society of Chemical Industry [source] Antibiotic-Loaded PLGA Nanofibers for Wound Healing Applications,ADVANCED ENGINEERING MATERIALS, Issue 4 2010David A. Soscia Incorporating antibiotics into biocompatible nanoscale non-woven fibrous mats could provide utility for wound healing applications and for incorporation into wound dressing materials. In this study, the antibiotic chloramphenicol (Cm) was incorporated into electrospun poly(lactic-co-glycolic acid) (PLGA) nanofibers, which were then tested for inhibition of bacterial growth for multiple bacterial species (Escherichia coli, Staphylococcus aureus, Bacillus cereus, Salmonella typhimurium, and Pseudomonas aeruginosa). In addition, the cytotoxicity of Cm-PLGA nanofibers was examined for two types of mammalian cells including mouse embryonic stem cells and fibroblasts. Electrospun PLGA nanofibers containing Cm were able to reduce bacterial growth on solid agar plates for all species except for P. aeruginosa. In liquid culture, Cm-loaded nanofibers inhibited growth for E. coli, B. cereus and S. typhimurium by 93% or greater, while P. aeruginosa and S. aureus growth was inhibited by 42% and 56%, respectively. Cm-loaded nanofibers showed limited cytoxicity on fibroblasts and embryonic stem cells, with viability greater than 96% for all conditions tested. These results suggest that Cm can be successfully incorporated into electrospun nanofibers and that these fibers could be used for wound healing applications with minimal cytotoxicity to the surrounding tissue. [source] Neurite Outgrowth on Nanocomposite Scaffolds Synthesized from PLGA and Carboxylated Carbon Nanotubes,ADVANCED ENGINEERING MATERIALS, Issue 12 2009Hyun Jung Lee Abstract Carbon nanotubes (CNTs) have been suggested as suitable materials for biomedical applications, especially in the neural area. It is essential not only to investigate the biocompatibility of CNTs with the neural system but also to determine proper methods for applying CNTs to neuronal growth. This work represents the first application of CNTs by electrospun poly(D,L -lactic-co-glycolic acid) (PLGA) scaffolds for a neural system. We synthesized electrospun nanocomposites of PLGA and single-walled carbon nanotubes functionalized by carboxylic acid groups (c- SWNTs), and investigated neurite outgrowth from SH-SY5Y cells on these nanocomposites as compared to that on fibrous PLGA alone. Cells on our PLGA/c -SWNT nanocomposite showed significantly enhanced mitochondrial function and neurite outgrowth compared to cells on PLGA alone. We concluded that c -SWNTs incorporated into fibrous PLGA scaffolds exerted a positive role on the health of neural cells. [source] A Solvent-Assisted Compression Molded of Poly(L -lactide)/Hydroxyapatite Electrospun Fibers for Robust Engineered Scaffold SystemsMACROMOLECULAR MATERIALS & ENGINEERING, Issue 10 2009Nguyen Dang Luong Abstract In an attempt to enhance the biocompatibility and mechanical strength of fibrous polymeric scaffold systems, nanocrystalline hydroxyapatite (HAp) particles were incorporated into the electrospun poly(L -lactide) (PLLA) fibers and then mechanically interlocked using a vapor-phase solvent adsorption method. The solvent-assisted compression molding substantially increased the tensile strength (from 4.61 to 12.63 MPa) and mechanical modulus (from 50.6 to 627.7 MPa) of the fibrous scaffold, which maintained the interstitial space between the fibers to allow the facile transport of nutrients and waste during cell growth and polymer biodegradation. Macrometer-sized pores (ca. 100,400,µm) were introduced into the scaffolds in a controlled fashion using the salt leaching/gas forming technique to give desired space for a facile cell implantation and growth. Overall, the developed methodology allows the polymer-based scaffold systems to be tailored for various applications in light of surface characteristics, mechanical strength, and pore size of engineered scaffolds. [source] Synthesis of pH-responsive crosslinked poly[styrene- co -(maleic sodium anhydride)] and cellulose composite hydrogel nanofibers by electrospinningPOLYMER INTERNATIONAL, Issue 5 2009Shengguang Cao Abstract BACKGROUND: Stimuli-sensitive materials show enormous potential in the development of drug delivery systems. But the low response rate of most stimuli-sensitive materials limits their wider application. We propose that electrospinning, a technique for the preparation of ultrafine fibrous materials with ultrafine diameters, may be used to prepare materials with a fast response to stimuli. RESULTS: Poly[styrene- co -(maleic sodium anhydride)] and cellulose (SMA-Na/cellulose) hydrogel nanofibers were prepared through hydrolysis of precursor electrospun poly[styrene- co -(maleic anhydride)]/cellulose acetate (SMA/CA) nanofibers. In the presence of diethylene glycol, the SMA/CA composite nanofibers were crosslinked by esterification at 145 °C, and then hydrolyzed to yield crosslinked SMA-Na/cellulose hydrogel nanofibers. These nanofibers showed better mechanical strengths and were pH responsive. Their water swelling ratio showed a characteristic two-step increase at pH = 5.0 and 8.2, with the water swelling ratio reaching a maximum of 27.6 g g,1 at pH = 9.1. CONCLUSION: The crosslinked SMA-Na hydrogel nanofibers supported on cellulose showed improved dimensional stability upon immersion in aqueous solutions. They were pH responsive. This new type of hydrogel nanofiber is a potential material for biomedical applications. Copyright © 2009 Society of Chemical Industry [source] | ||||||||||