Five types of nanofibrous membranes were prepared by electrospinning poly(ε-caprolactone) (PCL), poly(D,L-lactide) (PDLLA), poly(lactide-co-caprolactone) (P(LA/CL)), poly(D,L-lactide-co-glycolide) (PDLGA) and methoxy polyethylene glycol-poly(lactide-co-glycolide) (MPEG-PLGA), respectively. These electrospun nanofibrous membranes (ENFMs) were used to adsorb anthracene (ANT), benz[a]anthracene (BaA) and benzo[a]pyrene (BaP) from aqueous solution, and the sorption kinetics and isotherms of these PAHs on the five ENFMs were investigated. The pseudo-second-order model (PSOM) can well describe the sorption kinetics of the three PAHs on five ENFMs, and the partition-adsorption model (PAM) can interpret the sorption processes of PAHs on the ENFMs. PCL ENFMs, which had the largest surface areas (8.57 m(2)g(-1)), exhibited excellent sorption capacity for ANT at over 4112.3 ± 35.5 μg g(-1). Moreover, the hydrophobicity and pore volume of ENFMs significantly affected the sorption kinetics and sorption capacity

TY - JOUR. T1 - Proliferation of genetically modified human cells on electrospun nanofiber scaffolds. AU - Borjigin, Mandula. AU - Strouse, Bryan. AU - Niamat, Rohina A.. AU - Bialk, Pawel. AU - Eskridge, Chris. AU - Xie, Jingwei. AU - Kmiec, Eric B.. PY - 2012. Y1 - 2012. N2 - Gene editing is a process by which single base mutations can be corrected, in the context of the chromosome, using single-stranded oligodeoxynucleotides (ssODNs). The survival and proliferation of the corrected cells bearing modified genes, however, are impeded by a phenomenon known as reduced proliferation phenotype (RPP); this is a barrier to practical implementation. To overcome the RPP problem, we utilized nanofiber scaffolds as templates on which modified cells were allowed to recover, grow, and expand after gene editing. Here, we present evidence that some HCT116-19, bearing an integrated, mutated enhanced green fluorescent protein (eGFP) gene and corrected by gene editing, proliferate on polylysine or ...

Electrospinning technique was used to fabricate polyvinyl alcohol (PVA)-based magnetic biodegradable nanofibers. PVA solution was mixed with ferrofluid or magnetic nanoparticles (MNPs) powder and formed two individual nanofibrous membranes (PVA/ferrofluid and PVA/MNPs powder) by electrospinning. The surface morphology of the nanofibrous membrane was characterized by scanning electron microscopy and the magnetic properties were measured by vibrating sample magnetometer. Macrophages (RAW 264.7) were co-cultured with the nanofibrous membranes for 12, 24, and 48 h and exhibited good cell viability (,95%). Results showed that the PVA fibers would be degraded and the embedded Fe{sub 3}O{sub 4} nanoparticles would be released and delivered to cells. ...

There has been a considerable growth and development in electrospun nanofibers for research activity, as well as commercial fabrication over the past couple of decades. These continuous nanofibers are solution driven exclusively by an electric field. Numerous studies on electrospun fibrous scaffolds have demonstrated sufficient mechanical properties and support of cell growth for tissue engineering. Despite these substantial achievements, there is still an Edisonian-type procedure to acquire the desired scaffold orientation and mechanical response that mimics the native tissue behavior. In this study, the electrospun scaffolds are fabricated with different fiber orientation -i.e. aligned and patterned (0/90) - by modifying the electrospinning process, specifically electric field and target, over large areas and lengths (30 mm x 30 mm). Mechanical behavior of controlled scaffold parameters at nanoscale, e.g., fiber orientation, and porosity, is investigated for an effective tissue replacement. In

Electrospun nanofibrous SF/P(LLA-CL) membrane: a potential substratum for endothelial keratoplasty Junzhao Chen,1,* Chenxi Yan,1,* Mengyu Zhu,1,* Qinke Yao,1 Chunyi Shao,1 Wenjuan Lu,1 Jing Wang,2 Xiumei Mo,2 Ping Gu,1 Yao Fu,1 Xianqun Fan1 1Department of Ophthalmology, Ninth Peoples Hospital, Shanghai Jiao Tong University School of Medicine, 2Biomaterials and Tissue Engineering Laboratory, College of Chemistry and Chemical Engineering and Biotechnology, Donghua University, Shanghai, Peoples Republic of China *These authors contributed equally to this work Background: Cornea transplant technology has progressed markedly in recent decades, allowing surgeons to replace diseased corneal endothelium by a thin lamellar structure. A thin, transparent, biocompatible, tissue-engineered substratum with corneal endothelial cells for endothelial keratoplasty is currently of interest. Electrospinning a nanofibrous structure can simulate the extracellular matrix and have beneficial effects for cell culture.

TY - JOUR. T1 - Neurite outgrowth on electrospun nanofibers with uniaxial alignment. T2 - The effects of fiber density, surface coating, and supporting substrate. AU - Xie, Jingwei. AU - Liu, Wenying. AU - Macewan, Matthew R.. AU - Bridgman, Paul C.. AU - Xia, Younan. N1 - Copyright: Copyright 2014 Elsevier B.V., All rights reserved.. PY - 2014/2/25. Y1 - 2014/2/25. N2 - Electrospun nanofibers with uniaxial alignment have recently gained its popularity as scaffolds for neural tissue engineering. Many studies have demonstrated that the nanofibers could guide the neurites to extend along the direction of alignment, resembling the native hierarchy of the nerve tissue. However, the contact cues provided by the nanofibers can be far more complicated than just guiding the neurites to extend along them. In the current study, we used dorsal root ganglia as a model system to systematically investigate the interactions between neurites and uniaxially aligned nanofibers. We demonstrated, for the first ...

In this study, poly(vinyl alcohol) nanofibres were produced and evaluated for wound dressing applications. However, the solubility of the poly(vinyl alcohol) matrix in the aqueous medium generally limits its applications. To overcome this problem, 1,2,3,4 butanetetracarboxylic acid (BTCA) and citric acid (CA) were used as crosslinking agents. Successful bead-free nanofibres were produced, and they both preserved their fibrous structure after water treatment. The mean fibre diameters of polycarboxylic acid crosslinked nanofibres were lower compared to pure PVA nanofibres. Although the morphology of BTCA and CA crosslinked nanofibres was similar, the swelling degree of PVA/CA was found to be higher. Furthermore, toxicity and keratinocyte cell proliferation performance of produced PVA/BTCA and PVA/CA nanofibres indicated that these nanofibrous materials could be used in wound dressing applications. ...

TY - JOUR. T1 - Carbon Nanofibers Provide a Cationic Rectifier Material:. T2 - Specific Electrolyte Effects, Bipolar Reactivity, and Prospect for Desalination. AU - Marken, Frank. AU - Tshwenya, Luthando. AU - Arotiba, Omotayo. PY - 2019/6/14. Y1 - 2019/6/14. N2 - We demonstrate that ionic current rectification effects are observed with a film of negatively charged carbon nanofibers (CNFs) deposited as a film or mat onto a 10 μm diameter microhole in poly-ethylene-terephthalate (PET). CNFs are synthesized by using a chemical vapor deposition (CVD) method, followed by oxidation with hydrogen peroxide to introduce carboxyl moieties (providing negative surface charges). CNFs are characterized with transmission electron microscopy, scanning electron microscopy, elemental analysis, and zeta potential measurements. When drop-dried asymmetrically onto a 10 μm diameter cylindrical channel on a 6 μm thick PET substrate and placed as a membrane between two electrolyte compartments, ionic current ...

The accumulation of heavy metals in the human body and/or in the environment can be highly deleterious for mankind, and currently, considerable efforts have been made to develop reliable and sensitive techniques for their detection. Among the detection methods, chemical sensors appear as a promising technology, with emphasis on systems employing optically active nanofibers. Such nanofibers can be obtained by the electrospinning technique, and further functionalized with optically active chromophores such as dyes, conjugated polymers, carbon-based nanomaterials and nanoparticles, in order to produce fluorescent and colorimetric nanofibers. In this review we survey recent investigations reporting the use of optically active electrospun nanofibers in sensors aiming at the specific detection of heavy metals using colorimetry and fluorescence methods. The examples given in this review article provide sufficient evidence of the potential of optically electrospun nanofibers as a valid approach to fabricate

Electrospinning is a versatile method to fabricate nanofibers of a range of polymeric and composite materials suitable as scaffolds for tissue engineering applications. In this study, we report the fabrication and characterization of polyaniline-carbon nanotube/poly(N-isopropyl acrylamide-co-methacrylic acid) (PANI-CNT/PNIPAm-co-MAA) composite nanofibers and PNIPAm-co-MAA nanofibers suitable as a three-dimensional (3D) conducting smart tissue scaffold using electrospinning. The chemical structure of the resulting nanofibers was characterized with FUR and H-1 NMR spectroscopy. The surface morphology and average diameter of the nanofibers were observed by SEM. Cellular response of the nanofibers was studied with mice L929 fibroblasts. Cell viability was checked on 7th day of cell culture by double staining the cells with calcein-AM and PI dye. PANI-CNT/PNIPAm-co-MAA composite nanofibers were shown the highest cell growth and cell viability as compared to PNIPAm-co-MAA nanofibers. Cell viability in ...

UCLA REBAR Lab Background: Traumatic peripheral nerve injuries can result in lifelong disability. Primary nerve repair is used for short nerve defects. Autologous nerve can be used in longer defects but creates donor site morbidity. Nerve conduits lack an aligned internal scaffold to support and guide axonal regeneration. Peptide amphiphiles (PA) can self-assemble into aligned nanofibers and promote peripheral nerve regeneration in vivo. Bioactive epitopes IKVAV (Ile-Lys-Val-Ala-Val) and RGDS (Arg-Gly-Asp-Ser) can be incorporated into PA nanofibers and can promote cell adhesion, growth, and migration. There are no studies to date that examine the ability of PA nanofibers to support the regeneration of injured nerves that supply the musculoskeletal system. In this preliminary study, we investigate the viability of rat Schwann cells after incorporation into PA gels.. Methods: PA nanofibers were synthesized by Stupp et al. PAs were aqueously dissolved, and rat Schwann cells (cell line RT4-D6P2T) ...

Nanofibrous structures exhibit many interesting features, such as high surface area and surface functionalization and porosity in the range from submicron to nanoscale, which mimics the natural extracellular matrix. In particular, electrospun nanofibers have gained great attention in the field of tissue engineering due to the ease of fabrication and tailorability in pore size, scaffold shape, and fiber alignment. For the reasons, recently, polymeric nanofibers or bioceramic nanoparticle-incorporated nanofibers have been used in dentistry, and their nanostructure and flexibility have contributed to highly promotive cell homing behaviors, resulting in expecting improved dental regeneration. Here, this paper focuses on recently applied electrospun nanofibers in dentistry in the range from the process to the applications.

The study compared the biosensing properties of laccase biosensors based on carbon nanofibers (CNFs) and copper/carbon composite nanofibers (Cu/CNFs). The two kinds of nanofibers were prepared by electrospinning and carbonization under the same conditions. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy were employed to investigate the morphologies and structures of CNFs and Cu/CNFs. The amperometric results indicated that the Cu/CNFs/laccase(Lac)/Nafion/glass carbon electrode (GCE) possessed reliable analytical performance for the detection of catechol. The sensitivity of the Cu/CNFs/Lac/Nafion/GCE reached 33.1 μA/mM, larger than that of CNFs/Lac/Nafion/GCE. Meanwhile, Cu/CNFs/Lac/Nafion/GCE had a wider linear range from 9.95 × 10−6 to 9.76 × 10−3 M and a lower detection limit of 1.18 μM than CNFs/Lac/Nafion/GCE. Moreover, it exhibited a good repeatability, reproducibility, selectivity and long-term stability, revealing that electrospun Cu/CNFs have great

Immobilization of growth factors in scaffolds is important for controlling their dose and bioactivity for regenerative medicine applications. Although numerous covalent and noncovalent immobilization strategies have been proposed, better growth factor loading and dose control inside the scaffold is necessary. Nature of the binding site on the growth factor interacting with scaffold is critical for preserving and achieving maximal growth factor functionality, which has been a relatively less emphasized issue in previous studies. We recently reported heparin mimetic peptide nanofibers, which mimic chemistry of heparan sulfates. Heparin mimetic nanofibers were shown to bind to vascular endothelial growth factor (VEGF) and direct endothelial cells to angiogenesis. Here, we further investigated interactions between heparin mimetic peptide nanofibers and growth factors. We tested bioactivity of the nanofiber bound growth factors in order to understand the potential use of these peptide nanofiber ...

In this study, a novel osmotic membrane was developed by polyamide (PA) coating on the tubular electrospun nanofiber (TuEN) support membrane. Water and reverse salt flux properties of the obtained membrane were investigated by applying pressure in addition to the osmotic forces. Surface characterization of the membrane was carried out by Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analyses and flux performance tests were performed in both cross flow and submerged membrane setups. Applying pressure from the feed to the concentrate side had significant effects on the water and salt fluxes. Higher pressure differences between the feed and concentrate sides resulted in unexpected high water fluxes up to 500 Lm(-2)h(-1) (LMH). Besides, the pressure helps to transfer the salt content of feed water into the concentrate side, differently from the osmotic process preventing the salinity build-up at the feed side. PA coated TuEN membrane operated under pressure ...

李盛红,吴大朋,闫晓辉,&关亚风.(2015).Acetone-activated polyimide electrospun nanofiber membrane forthin-film microextraction and thermal desorption-gas chromatography-mass spectrometric analysis of phenols in environmental water.JOURNAL OF CHROMATOGRAPHY A,1411(0),1 ...

Proton-conductive electrospun nanofibers are promising potential materials for several advanced technological applications such batteries, sensors, and fuel cells. In this work, we prepared poly(vinyl butyral)/polyaniline (PVB/PANI) nanofibers via electrospinning and determined their proton conductivities. Structural characterization of the nanofibers was performed by FTIR analysis. Surface morphology of the nanofibers was determined by SEM and AFM. The addition of PANI significantly affected the fiber morphology, and over 90% reduction (with respect to neat PVB nanofibers) in the average nanofiber diameters was observed. Nanofiber mats were doped with polyphosphoric acid. The proton conductivity of the 2 wt.% PANI containing blend nanofibers was found as 18 x 10(-6) S/cm at room temperature and at 100% humidity. ...

In this thesis, changes in Youngs modulus of mesenchymal stem cells (MSCs) were investigated during their osteogenic differentiation on bioactive peptide nanofibers that bear triple glutamic acid sequence (EEE), a non-collagenous protein sequence of some extracellular matrix (ECM) proteins (e.g. bone sialoprotein) found in bone tissue. MSCs formed spherical cell aggregates on the osteoinductive peptide nanofibers, here also called osteospheroids, of which their cells made intensive cell-cell contacts and showed osteoblast-like cell morphology. Mechanical characterization of the osteospheroids on the peptide nanofiber hydrogel was performed using atomic force microscope (AFM) where AFM probes modified with a thin film coating of octa uorocyclobutane (C4F8) were used to measure force maps of the cells at days 3, 7 and 14 of osteogenic differentiation. Hertz Cone model, same as Sneddon, was applied to approach curves of 12 force curves per cell to calculate the Young s modulus values. As a result, ...

Vertically aligned multi-walled carbon nanofibers (CNFs) were grown by plasma-enhanced chemical vapor deposition with Ni catalysts on the top of nanofibers. Transmission electron microscopy was used to study the morphology and crystallography of Ni catalysts, which are essential for the nucleation and growth of CNFs. A model for the faceted shape of Ni catalytic particles is proposed. It is shown that the exposed polyhedral surfaces of Ni catalytic particles for vertically aligned CNFs are composed of {111}, {110}, and {100}, a faceting that appears to be characteristic of the growth atmosphere.

Stem cell and tissue engineering offer us with a unique opportunity to research and develop new therapies for treating various diseases that are otherwise incurable using traditional medicines. However, development of these new therapies replies upon the establishment of in vitro cell culture and differentiation systems that mimic in vivo microenvironments required for cell-cell and cell-ECM interaction. The development of these cell culture systems depends upon the identification of appropriate biomaterials and cell sources. Biomaterials should be carefully selected and fabricated into scaffolds for supporting cell growth and differentiation. In this study, we explored the fabrication of 3D electrospun nanofiber scaffolds and demonstrated the feasibility of using these scaffolds for supporting cell growth. The material that we used for scaffold fabrication is a polymer, polycaprolactone (PCL). We discovered that the electrospun PCL nanofibers are highly hydrophobic, unsuitable for cell growth. The

In this study, the adsorption of 1-chloro-4-nitrobenzene (1C4NB) on carbon nanofibers (CNFs), was investigated in a batch system. The combined effects of operating parameters such as contact time, pH, initial 1C4NB concentration, and CNFs dosage on the adsorption of 1C4NB byCNFs were analyzed using response surface methodology (RSM). The analysis of variance results confirmed that there was significant agreement between the model and experimental data. In addition, it was indicated that the residuals followed a normal distribution.The screening experiments showed that significant factors in 1C4NB removal were CNFs dosage, interaction between initial 1C4NB concentration-CNFs dosage and CNFs dosage-contact time. High efficiency removal (|90%) was obtained under optimal value of process parameters in the first 6 min of the removal process. The results indicate that RSM is a suitable method for modeling and optimizing the process, so that experimental design by RSM leads to time and cost saving.Non-linear

Among the synthetic polymers, poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microbial polyester is one of the biocompatible and biodegradable copolymers in the nanomedicine scope. PHBV has key points and suitable properties to support cellular adhesion, proliferation and differentiation of nanofibers. Nanofibers are noticeably employed in order to enhance the performance of biomaterials, and could be effectively considered in this scope. Electrospinning is one of the well-known and practical methods that extremely employed in the construction of nanofibrous scaffolds for biomedical application and recently PHBV has exploited in nerve graft and regenerative medicine. PHBV composites nanofibrous scaffolds are able to be applied as promising materials in many fields, such as; wound healing and dressing, tissue engineering, targeted drug delivery systems, functional carries, biosensors or nano-biosensors and so on. In this mini-review, we attempt to provide a more detailed overview of the recent

The clinical development of neuropeptides has been limited by a combination of the short plasma half-life of these drugs and their ultimate failure to permeate the blood brain barrier. Peptide nanofibres have been used to deliver peptides across the blood brain barrier and in this work we demonstrate that the polymer coating of peptide nanofibres further enhances peptide delivery to the brain via the intravenous route. Leucine(5)-enkephalin (LENK) nanofibres formed from the LENK ester prodrug - tyrosinyl(1)palmitate-leucine(5)-enkephalin (TPLENK) were coated with the polymer - N-palmitoyl-N-monomethyl-N,N-dimethyl-N,N,N-trimethyl-6-O-glycolchitosan (GCPQ) and injected intravenously. Peptide brain delivery was enhanced because the GCPQ coating on the peptide prodrug nanofibres, specifically enables the peptide prodrug to escape liver uptake, avoid enzymatic degradation to non-active sequences and thus enjoy a longer plasma half life. Plasma half-life is increased 520%, liver AUC0-4 decreased by ...

A hybrid electrode material for high-power supercapacitors was fabricated by grafting carbon nanofibers (CNFs) onto the surface of powdered activated carbon (AC) through catalytic chemical vapor deposition (CCVD). A uniform thin layer of disentangled CNFs with a herringbone structure was deposited on the carbon surface through the decomposition of propane at 450 °C over an AC-supported nickel catalyst. CNF coating was controlled by the reaction time and the nickel content. The superior CNF/AC composite displays excellent electrochemical performance in a 0.5 mol L−1 solution of K2SO4 due to its unique structure. At a high scan rate (100 mV s−1) and current loading (20 A g−1), the capacitance values were three- and fourfold higher than those for classical AC/carbon black composites. Owing to this feature, a high energy of 10 Wh kg−1 was obtained over a wide power range in neutral medium at a voltage of 0.8 V. The significant enhancement of charge propagation is attributed to the presence ...

An ultra-facile fabrication process for the preparation of phosphorus doped porous carbon nanofibers (P-PCNFs) through the electrospinning and heat treatment method has been studied. The materials were characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Studies showed that fabricated P-PCNFs have unique porous fibers structures, large specific surface area (462.83 cm2 g−1), and abundant microporous and mesoporous structures. X-ray photoelectron spectroscopy analyses revealed that the contents of phosphorus and electrochemical properties in a series of P-PCNF samples can be tuned by controlling the polyphosphoric acid concentration. The electrochemical properties of the materials were evaluated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. Studies showed that the specific capacitance of the fabricated P-PCNFs using the ultra-facile process reached up to 228.7 F g−1 at 0.5 A g−1 in 1 M ...

Site of the Professor Mohamed Hassan Abdelwahab El-Newehy: Academic Coordination Officer_DSP-KSU related to Faculties Websites at King Saud University

The nanofiber technology of present interest focuses on the electrospinning technique, which conveniently allows the preparation of fibrous materials with very fine diameters ranging from submicron to several nanometers. With the ability to form nanofibrous structures, a drive to mimic the extracellular matrix (ECM) and form scaffolds that are an artificial ECM suitable for tissue formation has begun. In addition, nanofibrous scaffolds have a high surface area-to-volume ratio, which is thought to enhance cell adhesion. Cell migration, proliferation and differentiation are dependent on adhesion and should be enhanced on nanofibrous scaffolds. Based on these, the main goals of the present work were to produce biodegradable nanofiber meshes with different topographies by electrospinning, in order to obtain diverse porosities and texture; to perform in vitro studies with an established cell line of Human primary osteogenic sarcoma (SaOs-2 cells), in order to observe cellular performance over these nanofiber

Researchers from the University of California-Riverside have announced the development of a low cost and efficient catalyst material used in polymer electrolyte membrane (PEM) fuel cells.. While traditional PEM catalysts depend on expensive platinum (Pt), this catalyst uses more abundant (and cheaper) metals (cobalt, iron, nickel) that are integrated into engineered carbon-fiber membranes to achieve needed performance in the fuel cell reaction.. Using a technique called electrospinning, the UCR researchers made paper-thin sheets of carbon nanofibers that contained metal ions - either cobalt, iron or nickel. Upon heating, the ions formed ultrafine metal nanoparticles that catalyzed the transformation of carbon into a high-performance graphitic carbon. Subsequently, the metal nanoparticles and residual nongraphitic carbon were oxidized, leading to a highly porous and useful network of metal oxide nanoparticles dispersed in a porous network of graphite.. If the membrane is able to tolerate carbon ...

Motoyama, Y., Lee, Y., Tsuji, K., Yoon, S.-H., Mochida, I. and Nagashima, H. (2011), Platinum Nanoparticles Supported on Nitrogen-doped Carbon Nanofibers as Efficient Poisoning Catalysts for the Hydrogenation of Nitroarenes. ChemCatChem, 3: 1578-1581. doi: 10.1002/cctc.201100135 ...

Page contains details about tin quantum dots-embedded carbon nanofibers . It has composition images, properties, Characterization methods, synthesis, applications and reference articles : nano.nature.com

TY - CONF. T1 - Risk assessment of polymer composites containing cellulose nanofibrils (CNF). AU - Kangas, Heli. AU - Pitkänen, Marja. AU - Wikström, Lisa. AU - Mannila, Juha. N1 - LIS: Abstract reviewed PY - 2016. Y1 - 2016. N2 - Cellulose nanofibrils (CNFs) have shown potential as strengthening agents in polymer composites. In addition, as bio-based nanomaterials originating from abundant raw material source, they offer sustainable alternative for manufacturing of light-weight composites with reduced carbon footprint. In general, CNFs have been found to pose no immediate threat to human health or to the environment. However, exposure to CNFs during production, use or end-of-life may lead, for example, to inflammatory effects of employees or unwanted adverse effects in the environment. In this presentation, risk assessment performed to polymer nanocomposites containing CNF will be reported. Exposure assessment will take into account occupational and consumer exposure as well as exposure to ...

Enhanced Critical Size Defect Repair in Rabbit Mandible by Electrospun Gelatin-β-TCP Composite Nanofibrous Membranes. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.

TY - JOUR. T1 - Multivariate analysis of variance (MANOVA) on the microstructure gradient of biomimetic nanofiber scaffolds fabricated by cone electrospinning. AU - Wang, Min. AU - Zhou, Yingge. AU - Tan, George Z.. PY - 2019/8. Y1 - 2019/8. N2 - Biomimetic scaffolds for tissue engineering should exhibit structural complexity close to native tissues, which typically have non-homogenous nanostructures. This study presents a novel electrospinning process using a cone-shape rotating collector to fabricate polymer nanofiber scaffold with continuous gradient microstructures. The effects of rotation speed (RS) and tip-to-axis distance (TAD) on microstructure gradients were investigated through multivariate analysis of variance (MANOVA), a generalization of univariate ANOVA that allows the researchers to analyze more than one dependent variable in designed experiments. The covariation against multivariate null hypotheses relative to error covariation was visualized through an ellipsoid plot. We found ...

The ability of dendritic cells to coordinate innate and adaptive immune responses makes them essential targets for vaccination strategies. Presentation of specific antigens by dendritic cells is required for the activation of the immune system against many pathogens and tumors, and nanoscale materials can be functionalized for active targeting of dendritic cells. In this work, we integrated an immunogenic, carbohydrate melanoma-associated antigen-mimetic GM3-lactone molecule into mannosylated peptide amphiphile nanofibers to target dendritic cells through DC-SIGN receptor. Based on morphological and functional analyses, when dendritic cells were treated with peptide nanofiber carriers, they showed significant increase in antigen internalization and a corresponding increase in the surface expression of the activation and maturation markers CD86, CD83 and HLA-DR, in addition to exhibiting a general morphology consistent with dendritic cell maturation. These results indicate that mannosylated ...

TY - JOUR. T1 - Simultaneous electrospin-electrosprayed biocomposite nanofibrous scaffolds for bone tissue regeneration. AU - Francis, Lijo. AU - Venugopal, J.. AU - Prabhakaran, Molamma P.. AU - Thavasi, V.. AU - Marsano, E.. AU - Ramakrishna, S.. PY - 2010/10. Y1 - 2010/10. N2 - Currently, the application of nanotechnology in bone tissue regeneration is a challenge for the fabrication of novel bioartificial bone grafts. These nanostructures are capable of mimicking natural extracellular matrix with effective mineralization for successful regeneration of damaged tissues. The simultaneous electrospraying of nanohydroxyapatite (HA) on electrospun polymeric nanofibrous scaffolds might be more promising for bone tissue regeneration. In the current study, nanofibrous scaffolds of gelatin (Gel), Gel/HA (4:1 blend), Gel/HA (2:1 blend) and Gel/HA (electrospin-electrospray) were fabricated for this purpose. The morphology, chemical and mechanical stability of nanofibres were evaluated by means of field ...

Introducing porosity in electrospun scaffolds is critical to improve cell penetration and nutrient diffusion for tissue engineering. Nanofibrous cellulose scaffolds were prepared by electrospinning cellulose acetate (CA) followed by saponification to regenerate cellulose. Using a computer-assisted design approach, scaffolds underwent laser ablation resulting in pores with diameters between 50 and 300 mu m. without damaging or modifying the surrounding scaffold area. A new mineralization method was employed in conjunction with microablation using commercial phosphate buffered saline (PBS) to soak carboxymethylcellulose surface-modified electrospun scaffolds. The resulting crystals within the scaffold on the interior of the pore had a calcium to phosphate ratio of 1.56, similar to hydroxyapatite. It was observed that porosity of the cellulose scaffolds enhanced osteoblast cell attachment at the edge of the pores, while mineralization enhanced overall cell density.

Composite fibres with a matrix of poly(ethylene glycol) (PEG) and cellulose nanofibrils (CNF) as reinforcing elements were produced using a capillary viscometer. Two types of CNF were employed: one based on carboxymethylated pulp fibres and the other on TEMPO-oxidized pulp. Part of the latter nanofibrils was also grafted with PEG in order to improve the compatibility between the CNF and the PEG matrix. The nominal CNF-content was kept at 10 or 30 weight-%. The composite fibres were characterized by optical and scanning electron microscopy in addition to dynamic mechanical thermal analysis (DMTA). Evaluation of the storage modulus indicated a clear reinforcing effect of the CNF, more pronounced in the case of the grafted CNF and depending on the amount of CNF. An interesting feature observed during the DMTA-measurements was that the fibrils within the composite fibres appeared to forma rather coherent and load-bearing network which was evident even after removing of the PEG-phase (by melting). An ...

Superhydrophobic electrospun polyacrylonitrile nanofibre membranes have been prepared by surface coating of silica nanoparticles and fluorinated alkyl silane. The coated membranes were characterised by scanning electron microscopy, water contact angle, thermogravimetry analysis, Brunauer-Emmett-Teller, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy. It was shown that the loading of nanoparticle on the nanofibre membrane was controlled by the particle concentration in the coating solution, which played a critical role in the formation of superhydrophobic surface. Increased particle loading led to higher surface roughness and WCA. The nanoparticle coating had little influence on the porosity of the nanofibre membranes. However, overloading of the particles would affect the specific surface area of the nanofibre membrane ...

TY - JOUR. T1 - Tubular hydrogels of circumferentially aligned nanofibers to encapsulate and orient vascular cells. AU - McClendon, Mark T.. AU - Stupp, Samuel I.. PY - 2012/8. Y1 - 2012/8. N2 - There is a great clinical need for tissue engineered blood vessels that could be used to replace or bypass damaged arteries. The success of such grafts will depend strongly on their ability to mimic the cellular and matrix organization found in native arteries, but currently available cell scaffolds such as electrospun fibers or hydrogels lack the ability to simultaneously encapsulate and align cells. Our laboratory has recently developed liquid crystalline solutions of peptide amphiphile nanofibers that form aligned domains at exceedingly low concentrations (,1wt%), and can be trapped as gels with macroscopic alignment using low shear rates and ionic crosslinking. We describe here the use of these systems to fabricate tubes with macroscopic circumferential alignment and demonstrate their potential as ...

One of the possible applications of nanofibres is water filtration. For this application a nanofibre flat-sheet membrane can be produced that can be used as a water filtration membrane. More specifically, this can be used in microfiltration. Due to their higher porosities and interconnected pore structures, nanofibres offer a higher permeability to water filtration than conventional materials currently in use (Thavasi et al., 2008). This study aims at assessing the possible use of electrospun nanofibre filters in water filtration. Firstly, physical properties such as clean water permeability (CWP) and strength were examined. Secondly, the use of the membrane (functionalised or non-functionalised) for the removal of pathogens was investigated and compared to previous studies. Thirdly, the application of the electrospun membranes for wastewater filtration in a submerged MBR was investigated. Methods. Membrane production process. The standard set-up for electrospinning consists of a spinneret with ...

Nanofibers were prepared from a nanocomposite consisting of polyacrylonitrile and a metal-organic framework of type MIL-53(Fe) by electrospinning. They are

Surface properties of scaffolds such as hydrophilicity and the presence of functional groups on the surface of scaffolds play a key role in cell adhesion, proliferation and migration. Different modification methods for hydrophilicity improvement and introduction of functional groups on the surface of scaffolds have been carried out on synthetic biodegradable polymers, for tissue engineering applications. In this study, alkaline hydrolysis of poly (ε-caprolactone) (PCL) nanofibrous scaffolds was carried out for different time periods (1 h, 4 h and 12 h) to increase the hydrophilicity of the scaffolds. The formation of reactive groups resulting from alkaline hydrolysis provides opportunities for further surface functionalization of PCL nanofibrous scaffolds. Matrigel was attached covalently on the surface of an optimized 4 h hydrolyzed PCL nanofibrous scaffolds and additionally the fabrication of blended PCL/matrigel nanofibrous scaffolds was carried out. Chemical and mechanical characterization ...

Transplanted retinal pigment epithelium (RPE) cells hold promise for treatment of age-related macular degeneration (AMD) and Stargardt disease (SD), but it is conceivable that the degenerated host Bruchs membrane (BM) as a natural substrate for RPE might not optimally support transplanted cell survival with correct cellular organization. We fabricated novel ultrathin three-dimensional (3-D) nanofibrous membranes from collagen type I and poly(lactic-co-glycolic acid) (PLGA) by an advanced clinical-grade needle-free electrospinning process. The nanofibrillar 3-D networks closely mimicked the fibrillar architecture of the native inner collagenous layer of human BM. Human RPE cells grown on our nanofibrous membranes bore a striking resemblance to native human RPE. They exhibited a correctly orientated monolayer with a polygonal cell shape and abundant sheet-like microvilli on their apical surfaces. RPE cells built tight junctions and expressed RPE65 protein. Flat 2-D PLGA film and cover glass as ...

TY - JOUR. T1 - Cellulose nanofibre aerogel filter with tuneable pore structure for oil/water separation and recovery. AU - He, Zhiyong. AU - Zhang, Xiwang. AU - Batchelor, Warren Jeffrey. PY - 2016. Y1 - 2016. N2 - A cellulose nanofibre aerogel filter with tuneable pore structure exhibiting super-hydrophilic and underwater-super-oleophobic behaviours is synthesized by a facile method of cross-linking between cellulose nanofibres and polyamideamine-epichlorohydrin (PAE). The prepared aerogel filter showed excellent oil/water separation efficiency for both oil/water mixtures (100 , even after 10 cycles), and oil/water surfactant-free emulsion (98.6 ), which is driven solely by gravity. In addition, the specific structure can de-emulsify oil/water emulsion. The results showed that the cellulose aerogel filter can be used for oil/water separation and recovery.. AB - A cellulose nanofibre aerogel filter with tuneable pore structure exhibiting super-hydrophilic and underwater-super-oleophobic ...

We report humidity sensing characteristics of CdTiO3 nanofibers prepared by electrospinning. The nanofibers were porous having an average diameter and length of similar to 50-200 nm and similar to 100 mu m, respectively. The nanofiber humidity sensor was fabricated by defining aluminum electrodes using photolithography on top of the nanofibers deposited on glass substrate. The performance of the CdTiO3 nanofiber humidity sensor was evaluated by AC electrical characterization from 40% to 90% relative humidity at 25 degrees C. The frequency of the AC signal was varied from 10(-1) to 10(6) Hz. Fast response time and recovery time of 4 s and 6 s were observed, respectively. The sensor was highly sensitive and exhibited a reversible response with small hysteresis of less than 7%. Long term stability of the sensor was confirmed during 30 day test. The excellent sensing characteristics prove that the CdTiO3 nanofibers are potential candidate for use in high performance humidity sensors.. ...

Recent work demonstrates that osteoprogenitor cell culture on nanofiber scaffolds can promote differentiation. This response may be driven by changes in cell morphology caused by the three-dimensional (3D) structure of nanofibers. We hypothesized that nanofiber effects on cell behavior may be mediated by changes in organelle structure and function. To test this hypothesis, human bone marrow stromal cells (hBMSCs) were cultured on poly(ϵ-caprolactone) (PCL) nanofibers scaffolds and on PCL flat spuncoat films. After 1 day-culture, hBMSCs were stained for actin, nucleus, mitochondria, and peroxisomes, and then imaged using 3D confocal microscopy. Imaging revealed that the hBMSC cell body (actin) and peroxisomal volume were reduced during culture on nanofibers. In addition, the nucleus and peroxisomes occupied a larger fraction of cell volume during culture on nanofibers than on films, suggesting enhancement of the nuclear and peroxisomal functional capacity. Organelles adopted morphologies with greater 3D

The penetration and residence of vertically aligned carbon nanofibers (VACNF) within live cell matrices is demonstrated upon substrates that incorporate spatially registered indices to facilitate temporal tracking of individual cells. Penetration of DNA-modified carbon nanofibers into live cells using this platform provides efficient delivery and expression of exogenous genes, similar to microinjection-styled methods, but on a massively parallel basis. Spatially registered indices on the substrate allow one to conveniently locate individual cells, facilitating temporal tracking of gene expression events. We describe fabrication and use of this gene delivery platform which consists of arrays of individual carbon nanofibers at 5 ...

Polyvinyl alcohol (PVA) nanofibers and single-walled carbon nanotube (SWNT)/PVA composite nanofibers have been produced by electrospinning. An apparent increase in the PVA crystallinity with a concomitant change in its main crystalline phase and a reduction in the crystalline domain size were observed in the SWNT/PVA composite nanofibers, indicating the occurrence of a SWNT-induced nucleation crystallization of the PVA phase. Both the pure PVA and SWNT/PVA composite nanofibers were subjected to the following post-electrospinning treatments: (i) soaking in methanol to increase the PVA crystallinity, and (ii) cross-linking with glutaric dialdehyde to control the PVA morphology. Effects of the PVA morphology on the tensile properties of the resultant electrospun nanofibers were examined. Dynamic mechanical thermal analyses of both pure PVA and SWNT/PVA composite electrospun nanofibers indicated that SWNT-polymer interaction facilitated the formation of crystalline domains, which can be further ...

Page contains details about high oxygen-containing iron-nitrogen-amorphous carbon nanofibers/Nafion composite film . It has composition images, properties, Characterization methods, synthesis, applications and reference articles : nano.nature.com

Despite advancements in wound healing techniques and devices, new treatments are needed to improve therapeutic outcomes. This study aimed to evaluate the potential use of a new biomaterial engineered from human urine-derived stem cells (USCs) and polycaprolactone/gelatin (PCL/GT) for wound healing. USCs were isolated from healthy individuals. To fabricate PCL/GT composite meshes, twin-nozzle electrospinning were used to spin the PCL and gelatin solutions in normal organic solvents. The morphologies and hydrophilicity properties of PCL/GT membranes were investigated. After USCs were seeded onto a PCL/GT, cell adhesion, morphology, proliferation, and cytotoxicity were examined. Then, USCs were seeded on a PCL/GT blend nanofibrous membrane and transplanted into rabbit full-thickness skin defects for wound repair. Finally, the effect of USCs condition medium on proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) were performed in vitro. USCs were successfully

Far-infrared radiation effect and antibacterial properties were introduced in PVA nanofibrous membrane using germanium (Ge) and silicon dioxide (SiO2).

Alpha-melanocyte stimulating hormone (α-MSH) is involved in normal skin wound healing and also has anti-inflammatory properties. The association of α-MSH to polyelectrolyte layers with various supports has been shown to improve these anti-inflammatory properties. This study aimed to evaluate the effects of nanofibrous membrane functionalized with α-MSH linked to polyelectrolyte layers on gingival cell inflammatory response. Human oral epithelial cells (EC) and fibroblasts (FB) were cultured on plastic or electrospun Poly-#-caprolactone (PCL) membranes with α-MSH covalently coupled to Poly-L-glutamic acid (PGA-α-MSH), for 6 to 24 h. Cells were incubated with or without Porphyromonas gingivalis lipopolysaccharide (Pg-LPS). Cell proliferation and migration were determined using AlamarBlue test and scratch assay. Expression of interleukin-6 (IL-6), tumor necrosis factor (TNF-α), and transforming growth factor-beta (TGF-β) was evaluated using RT-qPCR method. Cell cultures on plastic showed that PGA-α

Title:Antifungal Activity of Eugenol Loaded Electrospun PAN Nanofiber Mats Against Candida Albicans. VOLUME: 15 ISSUE: 6. Author(s):Kourosh Semnani, Masoomeh Shams-Ghahfarokhi*, Mehran Afrashi, Aref Fakhrali and Dariush Semnani*. Affiliation:Department of Mycology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran 14115-331, Department of Mycology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran 14115-331, Department of Textile Engineering, Isfahan University of Technology, Isfahan 84156-83111, Department of Textile Engineering, Isfahan University of Technology, Isfahan 84156-83111, Department of Textile Engineering, Isfahan University of Technology, Isfahan 84156-83111. Keywords:Candida albicans, eugenol, electrospinning, antifungal activity, PAN nanofiber, SEM.. Abstract:Background: Eugenol, as the major phenolic component of clove essential oil due to its desired properties in medical field, was loaded into polyacrylonitrile (PAN) nanofibers with various ...

Poly-3-hexylthiophene (P3HT) nanofibers are 1D crystalline semiconducting nanostructures, which are known for their application in photovoltaics. Due to the internal arrangement, P3HT nanofibers possess optical anisotropy, which can be enhanced on a macroscale if nanofibers are aligned. Alternating electric field, applied to a solution with dispersed nanofibers, causes their alignment and serves as a method to produce solid layers with ordered nanofibers. The transmission ellipsometry measurements demonstrate the dichroic absorption and birefringence of ordered nanofibers in a wide spectral range of 400-1700 nm. Moreover, the length of nanofibers has a crucial impact on their degree of alignment. Using electric birefringence technique, it is shown that external electric field applied to the solution with P3HT nanofibers can cause direct birefringence modulation. Dynamic alignment of dispersed nanofibers changes the refractive index of the solution and, therefore, the polarization of transmitted ...

Cellulose nanofibers showed varied application in filters, medical and composites reinforcement attributed toabundant resources, large specific surface area, biocompatibility and biodegradation. In this study the feasibilityof using wheat bran as a vast product of wheat cultivation to produce cellulose nanofibers was investigated. Extracting cellulose from wheat bran was carried out by means of chemical-mechanical procedure. The structure, chemical composition and thermal properties of cellulose fibers were characterized by means of Scanning Electronic Microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and Differential Scanning Calorimetry (DSC). Finally, cellulose nanofibers were produced via an electrospinning method using Trifluoroacetic acid (TFA) as the solvent. Electrospinning has been successfully demonstrated as a one step process to produce nanofibers, thereby showing great potential for reducing cost and making the fiber producing process more environmental friendly. The ability

We report a facile one-step route to graft poly(ionic liquid)s (PILs) onto cellulose nanofibrils (CNFs). The dispersibility of the PIL-functionalized CNFs in water and various organic solvents could be tuned by the choice of the PIL-binding anion. We demonstrate that such omnidispersible [email protected] hybrids can be used to reinforce porous poly(ionic liquid) membranes.. ...

We report a facile one-step route to graft poly(ionic liquid)s (PILs) onto cellulose nanofibrils (CNFs). The dispersibility of the PIL-functionalized CNFs in water and various organic solvents could be tuned by the choice of the PIL-binding anion. We demonstrate that such omnidispersible [email protected] hybrids can

Bulk polymers are generally regarded as thermal insulators, and typically have thermal conductivities on the order of 0.1 W m−1 K−1 (ref. 1). However, recent work2,3,4 suggests that individual chains of polyethylene-the simplest and most widely used polymer-can have extremely high thermal conductivity. Practical applications of these polymers may also require that the individual chains form fibres or films. Here, we report the fabrication of high-quality ultra-drawn polyethylene nanofibres with diameters of 50-500 nm and lengths up to tens of millimetres. The thermal conductivity of the nanofibres was found to be as high as ∼104 W m−1 K−1, which is larger than the conductivities of about half of the pure metals. The high thermal conductivity is attributed to the restructuring of the polymer chains by stretching, which improves the fibre quality toward an ideal single crystalline fibre. Such thermally conductive polymers are potentially useful as heat spreaders and could supplement

ABDUL-QUADIR, M.S. et al. Selective Removal of Organonitrogen Compounds in Fuel using Functional Polybenzimidazole Nanofibres: A Combined Experimental and Theoretical Study. S.Afr.j.chem. (Online) [online]. 2019, vol.72, pp.88-100. ISSN 1996-840X. http://dx.doi.org/10.17159/0379-4350/2019/v72a12.. Organonitrogen compounds present in fuel oils are deleterious to the environment as well as refining catalysts. Herein, functional polybenzimidazole (PBI) nanofibres fabricated in the presence of N-compounds (nitrogen-containing compounds) were employed for the selective adsorption of quinoline, pyrimidine and carbazole, largely found in diesel fuel. Adsorption capacities of 11.5 mg g-1,11.8 mg g-1 and 11.0 mg g-1 were observed for pyrimidine, carbazole and quinoline, respectively. Density functional theory (DFT) studies indicated π-π interactions/stacking and hydrogen bond interactions between the nitrogen atom of N-compounds and PBI. The study clearly shows the potential of PBI material use for the ...

TY - JOUR. T1 - Quantifying the interactions between biomimetic biomaterials - collagen I, collagen IV, laminin 521 and cellulose nanofibrils - by colloidal probe microscopy. AU - Nugroho, Robertus Wahyu N.. AU - Harjumäki, Riina. AU - Zhang, Xue. AU - Lou, Yan Ru. AU - Yliperttula, Marjo. AU - Valle-Delgado, Juan José. AU - Österberg, Monika. PY - 2019/1/1. Y1 - 2019/1/1. N2 - Biomaterials of different nature have been and are widely studied for various biomedical applications. In many cases, biomaterial assemblies are designed to mimic biological systems. Although biomaterials have been thoroughly characterized in many aspects, not much quantitative information on the molecular level interactions between different biomaterials is available. That information is very important, on the one hand, to understand the properties of biological systems and, on the other hand, to develop new composite biomaterials for special applications. This work presents a systematic, quantitative analysis of ...

All-polysaccharide composite films were prepared from native, unmodified cellulose nanofibrils (CNF) mixed with various natural water-soluble polysaccharides like carboxymethyl cellulose, galactoglucomannan, xyloglucan and guar gum. Composite films were manufactured by pressurized filtration and hot pressing. The mechanical properties of the films were systematically evaluated in the dry and the wet state. GG was furthermore selectively oxidized using galactose oxidase (EC 1.1.3.9), and the effect of the degree of oxidation on the final composite film properties was shown. It was found that all the tested polysaccharides increased the strength and toughness of the dry composite films at 2 weight percent (wt.%) addition to CNF. After soaking the samples for 24 h in water, striking differences between the samples were found: already at 2 wt.% CMC the wet strength of the composite films diminished, while the uncharged polysaccharides improved the wet strength. For example, the addition of 2 wt.% ...

The biodegradation behavior of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized cellulose fibers (TOCs) suspended in water and TEMPO-oxidized cellulose nanofibrils (TOCNs) dispersed in...

Read Cu(acac)2-PVA composite nanofibers in catalysis of Michael addition of carbon nucleophiles to α,β-unsaturated carbonyl compounds, Iranian Polymer Journal on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.

The Department of Mechanical Engineering of the Hong Kong Polytechnic University (PolyU) has developed a novel technology of embedding highly conductive nanostructure into semi-conductor nanofibre. The novel composite so produced has superb charge conductivity, and can therefore be widely applied, especially in environmental arena. The innovation was awarded the Gold Medal with congratu ..

The nanofiber plasmon effect on the two-photon polymerization (2PP) induced by a femtosecond laser is reported for the first time in this paper. The nanofibers were generated using a femtosecond laser, which was also used to construct microfeatures through two-photon polymerization of a nanofiber dispersed polymer resin. Nanofiber plasmon resonant effect greatly enhances local field intensities, resulting in increased particle scattering cross sections. This leads to a drastic enhancement of two-photon-like absorption processes, allowing much lower incident radiation intensities to be used. The huge enhancements in local field intensity due to nanofiber plasmon resonances have been shown to lower the required intensity for 2PP by factors of 10 or more.. ...

The present study was aimed to investigate different methods of activation of carbon nanofibres, CNF, in order to determine the beneficial effect on the hydrogen sorption capacities of increasing the surface area. Two activation systems were used: physical activation with CO2 and chemical activation with KOH. A range of potential adsorbents were thus prepared by varying the temperature and time of activation. The structure of the CNF proved more suitable to activation by KOH than by CO2, with the former yielding higher surface area carbons (up to 1000 m2 g−1). The increased surface area, however, did not correspond directly with a proportional increase in hydrogen adsorption capacity. Although high surface areas are important for hydrogen storage by adsorption on solids, it would appear that it is essential that not only the physical, but also the chemical, properties of the adsorbents have to be considered in the quest for carbon based materials, with high hydrogen storage capacities ...

Based on a technology licensed through The Ohio State University, Nanofiber Solutions is a global developer, manufacturer and marketer of 3-D products to advance life science research, tissue engineering and regenerative medicine. The company develops nanofiber-based scaffolds used in products ranging from cell culture plates for lab research to bioartificial implants for clinical use. Nanofiber Solutions sells our cell culture products worldwide through our website and distribution partners; including Sigma-Aldrich (worldwide), Neuromics (US), Akron Biotech (US), and Cambridge BioScience (UK). Nanofiber Solutions is located in the TechColumbus center in Columbus, OH ...

TY - JOUR. T1 - Optimization of Sonic Hedgehog Delivery to the Penis from Self-Assembling Nanofiber Hydrogels to Preserve Penile Morphology after Cavernous Nerve Injury. AU - Choe, Shawn. AU - Kalmanek, Elizabeth. AU - Bond, Christopher. AU - Harrington, Daniel A.. AU - Stupp, Samuel I.. AU - McVary, Kevin T.. AU - Podlasek, Carol A.. PY - 2019/8. Y1 - 2019/8. N2 - Erectile dysfunction (ED) is a significant medical condition, with high impact on patient quality of life. Current treatments are minimally effective in prostatectomy, diabetic and aging patients due to injury to the cavernous nerve (CN); loss of innervation causes extensive smooth muscle (SM) apoptosis, increased collagen and ED. Sonic hedgehog (SHH) is a critical regulator of penile SM. We developed a self-assembling peptide amphiphile (PA) nanofiber hydrogel for extended release of SHH protein to the penis after CN injury, to suppress SM apoptosis. In this study we optimize the animal model, SHH concentration, duration of ...

Understanding the material properties of the nanofibers comprising electrospun scaffolds for tissue engineering will elucidate the mechanotransduction of cells seeded onto and attached those scaffolds. The overall mechanical properties of any structure built from fibers depend on 1) the architecture, 2) the properties of the constituent single fibers, and 3) the junctions between fibers. All three must be known to design a structure with predictable mechanical properties. We hypothesize that a basic understanding of the nanolevel mechanical properties of individual electrospun fibers will enable accurate prediction of the overall cellular response and bulk mechanical behavior of electrospun tissue scaffolds.. Copyright © 2010 by ASME ...

Deep eutectic solvents (DESs), as emerging green solvents, provide a new opportunity for the biorefinement of biomass, component extraction, and cellulose nanofibrillation. Herein, different carboxylic acid-based DESs were applied for preparation of cellulose nanofibers (CNFs) from cellulose raw materials accompanied by simultaneous esterification modifications of CNFs. The results showed that pretreatment of DESs combined with mechanical treatment can swell and esterify the cellulose materials, producing CNFs with widths less than 100 nm. The DES pretreatment temperature played important roles in the esterification modifications and nanofibrillation of cellulose. The esterification modifications of cellulose prevented the over-hydrolysis and dissolution of cellulose during the DES pretreatment, guaranteeing CNFs with high yields of 72 %-88 % and maintaining the cellulose I crystal structure. Moreover, the esterified CNFs were used as a reinforcement to prepare CNF-strengthened polylactic acid ...

Satoru Yoshida of Asahi Kasei Fibers Corp., Moriyama City (Japan) has produced nanofibres by refining woodpulp into the 30 to 100 nm fibril range and producing wet-laid sheets down to 3 gsm with comparable surface area and porosity to electrospun nanofibres. The sheets also show unusually high heat stability (better than hydrophilic PTFE film) and a usefully lower coefficient of thermal expansion than cellophane film. ...

0011] The device described in WO-2005/073441-A1 comprises a nozzle block comprising multiple nozzles, a collector for collecting fibres being spun from the nozzle block and a voltage generator for applying a voltage to the nozzle block and the collector. The polymer used in WO2005/073441 is a nylon 6 with a relative viscosity of 3.2 (determined in a 96% sulfuric acid solution), which corresponds with an Mw of 48,000 g/mol. The polymer is used in for making spinning liquids, e.g. with a viscosity of 1050 cPs at 20% solids. According to WO2005/073441, electrospinning is generally carried out at a very low throughput rate of 102 to 10.sup.˜3 g/min per hole. For that reason electrospinning done at one hole is not suited for mass production needed for commercialization purposes. Large scale electrospinning devices used for mass production needed in commercialization, comprise a plurality of nozzles which should be arranged in a narrow space. However, in the conventional electrospinning devices, it ...

0031]With reference to FIG. 5, inputs to isolation transformer 492 include a DC input 425 from multi-DC power supply 420, and a pair of out-of-phase AC inputs 461, 463 from 3 phase AC supplies 482, 484. Inputs to isolation transformer 494 include a DC input 426 from multi-DC power supply 420, and a pair of out-of-phase AC inputs 465, 467 from 3 phase AC supplies 484, 486. Inputs to isolation transformer 496 include a DC input 427 from multi-DC power supply 420, and a pair of out-of-phase AC inputs 469, 471 from 3 phase AC supplies 482, 486. In order to pass the DC signals to the electrodes, the DC inputs are connected to the secondary winding of each respective isolation transformer, while the AC inputs are connected to the respective primary windings. The combined DC+AC outputs 452, 454, 456 are connected to respective electrodes. The magnitude and phase of the inputs and outputs according to the present embodiment are summarized in Table 1 ...

In the present work, an electrospun nanofibrous textile composed of polyurethane (PU), sodium bicarbonate(NaHCO3) and pantothenic acid (PA) is developed for treating chronic wounds. Wounds are a common health problemand in particular, the chronic wounds such as vascular ulcers, diabetic ulcers and pressure ulcers cause a large number ofmorbidity and mortality. The main problems of the chronic wounds are prolonged inflammation phase and presence of acidicenvironment. These events deactivate the operation of growth factors and also the progression of natural healing mechanism.Hence, various types of advanced textile-based dressings are developed to address the clinical complications associated withchronic wound management. The prepared electrospun scaffolds were characterized to study their physicochemical andhaemocompatible properties. The scanning electron microscopy micrographs depicted continuous, smooth-interconnectednanofibrous morphology of PU-NaHCO$_3$-PA scaffolds. The Fourier transform ...

The delivery of therapeutic peptides and proteins to the central nervous system is the biggest challenge when developing effective neuropharmaceuticals. The central issue is that the blood-brain barrier is impermeable to most molecules. Here we demonstrate the concept of employing an amphiphilic derivative of a peptide to deliver the peptide into the brain. The key to success is that the amphiphilic peptide should by design self-assemble into nanofibers wherein the active peptide epitope is tightly wrapped around the nanofiber core. The nanofiber form appears to protect the amphiphilic peptide from degradation while in the plasma, and the amphiphilic nature of the peptide promotes its transport across the blood-brain barrier. Therapeutic brain levels of the amphiphilic peptide are achieved with this strategy, compared with the absence of detectable peptide in the brain and the consequent lack of a therapeutic response when the underivatized peptide is administered.. ...

The delivery of therapeutic peptides and proteins to the central nervous system is the biggest challenge when developing effective neuropharmaceuticals. The central issue is that the blood-brain barrier is impermeable to most molecules. Here we demonstrate the concept of employing an amphiphilic derivative of a peptide to deliver the peptide into the brain. The key to success is that the amphiphilic peptide should by design self-assemble into nanofibers wherein the active peptide epitope is tightly wrapped around the nanofiber core. The nanofiber form appears to protect the amphiphilic peptide from degradation while in the plasma, and the amphiphilic nature of the peptide promotes its transport across the blood-brain barrier. Therapeutic brain levels of the amphiphilic peptide are achieved with this strategy, compared with the absence of detectable peptide in the brain and the consequent lack of a therapeutic response when the underivatized peptide is administered.. ...

Intrarenal drug delivery from a hydrogel carrier implanted under the kidney capsule is an innovative way to induce kidney tissue regeneration and/or prevent kidney inflammation or fibrosis. We report here on the development of supramolecular hydrogels for this application. We have synthesized two types of supramolecular hydrogelators by connecting the hydrogen bonding moieties to poly(ethylene glycols) in two different ways in order to obtain hydrogels with different physico-chemical properties. Chain-extended hydrogelators containing hydrogen bonding units in the main chain, and bifunctional hydrogelators end-functionalized with hydrogen bonding moieties, were made. The influence of these hydrogels on the renal cortex when implanted under the kidney capsule was studied. The overall tissue response to these hydrogels was found to be mild, and minimal damage to the cortex was observed, using the infiltration of macrophages, formation of myofibroblasts, and the deposition of collagen III as ...

More than 200 polymers are used for electrospinning like silk fibroin (Zarkoob et al., 2004; Sukigara et al., 2003; Jin et al., 2004), collagen (Mathews et al., 2002), chitosan (Ohkawa et al., 2004), gelatin (Ma et al., 2005) etc. In the field of tissue engineering electrospinning technique is applied for the preparation of nanofiber scaffold design. The process is very versatile in terms of use of polymers, non-invasive and does not require the use of coagulation chemistry or high temperature for fiber generation. ...

Retinyl acetate (RA) was effectively incorporated into nano-fibers of polyvinyl alcohol (PVA) at 10% (w/w) of PVA in order to develop encapsulating for prolong...

The reknowned capabilities of TiO2-based materials in photocatalytic oxidation of organic pollutants and in photoelectrochemical conversion of solar energy are inherently limited by the poor quantum efficiency of titanium. Research in this area is targeting improved generation and separation of photoinduced electron-hole pairs in TiO2 in order to enhance photocatalytic activity.. In this CrystEngComm Advance Article, Mingyi Zhang and colleagues at the Northeast Normal University in Changchun, China, report the synthesis and characterisation of a series of Bi2MoO6 nanostructures grown on TiO2 nanofibers. These hierarchical heterostructures demonstrate improved photocatalytic activity due to the narrow band gap energy of Bi2MoO6 which be easily excited by visible light to induce the generation of photoelectrons and holes.. The novel synthetic route to these nanofibers combines both the electrospinning technique and the solvothermal method in order to tune the coverage density and morphology of the ...

Neural tissue may be reconstructed with biocompatible nanofiber scaffolding and 3-D hydrogels, holding much promise for repairing damaged neural tissue.

Site of the Professor Mohamed Hassan Abdelwahab El-Newehy: Academic Coordination Officer_DSP-KSU related to Faculties Websites at King Saud University

This is a significant development, as drinking water contaminated with bacteria and viruses is the main cause of many diseases in development countries. The production of nanofibre membranes is one of the greatest breakthroughs in the water treatment industry especially because of the structural properties of these fibres. The fibres have a high surface area which allows a higher adsorption rate of various trace organics and bacteria for improving water quality; a higher acid/basic and temperature resistance; environmental friendliness, and longer membrane life span and flexibility which enables the membrane to be formed into various membrane modules for larger commercial application.. The research focuses on developing functionalised nanofibre membranes to obtain antimicrobial and antifouling properties and applying the technology to develop low cost water treatment systems. Nanofibres are produced by a simple, rapid and inexpensive method namely electrospinning. Nanobiocides such as metal ...

Stem Cells International is a peer-reviewed, Open Access journal that publishes original research articles, review articles, and clinical studies in all areas of stem cell biology and applications. The journal will consider basic, translational, and clinical research, including animal models and clinical trials.

Abstract. Synthetic peptides that self-assemble into well-defined structures with a cross-β arrangement are called amyloid-like fibrils. Amyloids are associated with a list of disorders and neuro-degenerative diseases, such as Alzheimers and Parkinson`s disease. We previously showed that amyloid-like nanofibrils with a repeating motif IHIH were functional fibrils. They were able to bind a metal ion through imidazole moieties and mimic the native carbonic anhydrase enzyme by hydrolysing the CO2 molecule. Thus, these synthetic amyloid fibrils were suggest-ed to be good candidates to moderate and update the modern enzymatic molecules. This study aims to shed a light on the stability of these amyloid nanofibrils over a study period of 25 days, in the presence/absence of a metal ion. The work continued for approximately 7 months in the Biochemistry department, School of Life Sciences at the University of Sussex in the United Kingdom. A set of designed peptides with a repeating motif IHIH were ...

Fibronectin fibrillogenesis is the physiological process by which cells elaborate a fibrous FN matrix. Poly(ethyl acrylate), PEA, has been described to induce a similar process upon simple adsorption of fibronectin (FN) from a protein solution-in the absence of cells-leading to the so-called material-driven fibronectin fibrillogenesis. Poly(methyl acrylate), PMA, is a polymer with very similar chemistry to PEA, on which FN is adsorbed, keeping the globular conformation of the protein in solution. We have used radical polymerization to synthesize copolymers with controlled EA/MA ratio, seeking to modulate the degree of FN fibrillogenesis. The physicochemical properties of the system were studied using dynamic mechanical analysis, differential scanning calorimetry, and water contact angle. Both the degree of FN fibrillogenesis and the availability of the integrin binding region of FN directly depend on the percentage of EA in the copolymer, whereas the same total amount of FN was adsorbed ...

A common problem in the design of tissue engineered scaffolds using electrospun scaffolds is the poor cellular infiltration into the structure. To tackle this issue, three approaches to scaffold design using electrospinning were investigated: selective leaching of a water-soluble fiber phase (poly ethylene oxide (PEO) or gelatin), the use of micron-sized fibers as the scaffold, and a combination of micron-sized fibers with codeposition of a hyaluronic acid-derivative hydrogel, Heprasil. These designs were achieved by modifying a conventional electrospinning system with two charged capillaries and a rotating mandrel collector. Three types of scaffolds were fabricated: medical grade poly(ε-caprolactone)/collagen (mPCL/Col) cospun with PEO or gelatin, mPCL/Col meshes with micron-sized fibers, and mPCL/Col microfibers cosprayed with Heprasil. All three scaffold types supported attachment and proliferation of human fetal osteoblasts. However, selective leaching only marginally improved cellular ...

The mechanical properties of nanofiber reinforced polymer microstructures were investigated in this work by means of nanoindentation. The femtosecond laser was used to generate nanofibers on selected area on the surface of the substrate and to generate microstructures. These microstructures were formed via two photon polymerization using femtosecond laser material processing by incorporation of silicon nanofibers into Ormocer matrix. Results show that the hardness and elastic modulus of the nanocomposites have improved by 25% and 75%, respectively, with the incorporation of nanofibers using the described method, which has the potential of direct fabrication of reinforced micro-/nanostructures. The volume fraction of the generated nanofibers in the nanocomposite was calculated by using nanoindentation analysis.. ...