Search results for "nanofiber"
showing 10 items of 107 documents
An asymmetric electrospun membrane for the controlled release of ciprofloxacin and FGF-2: Evaluation of antimicrobial and chemoattractant properties.
2021
Here, an asymmetric double-layer membrane has been designed and fabricated by electrospinning as a tool for a potential wound healing application. A hydrophobic layer has been produced by using a polyurethane-polycaprolactone (PU-PCL) copolymer and loaded with the antibacterial ciprofloxacin whereas an ion responsive hydrophilic layer has been produced by using an octyl derivative of gellan gum (GG-C8) and polyvinyl alcohol (PVA) and loaded with the growth factor FGF-2. This study investigated how the properties of this asymmetric membrane loaded with actives, were influenced by the ionotropic crosslinking of the hydrophilic layer. In particular, the treatment in DPBS and the crosslinking i…
Morphology and structure of electrospun CoFe2O4/multi-wall carbon nanotubes composite nanofibers
2010
CoFe2O4/multiwall carbon nanotubes (MWCNTs) composite nanofibers were produced by electrospinning a dispersion of MWCNTs in a solution of polyvinylpyrrolidone, iron(III) nitrate nonahydrate, cobalt (II) acetate tetrahydrate, absolute ethanol and H2O. Microstructure was examined by scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HR-TEM). Thermal behaviour was studied by thermogravimetry and differential thermal analysis (TG-DTA) and phase analysis of calcined fibers was performed by X-ray diffraction (XRD). Upon thermal treatment at 450 °C defect-free, randomly oriented composite fibers having a mean diameter of 60 ± 10 nm were obtained. The results s…
Antimicrobial Bilayer Nanocomposites Based on the Incorporation of As-Synthetized Hollow Zinc Oxide Nanotubes
2020
© 2020 by the authors.
Bioengineering of the silica-polymerizing enzyme silicatein-alpha for a targeted application to hydroxyapatite.
2009
Since its discovery, numerous biotechnological approaches have aimed to explore the silica-polymerizing catalytic activity of the enzyme silicatein. In vivo, silicatein catalyzes polymerization of amorphous silica nanospheres from soluble precursors. In vitro, it directs the formation of nanostructured biosilica. This is of interest for various applications that strive to benefit from both the advantages of the biological system (i.e., silica synthesis under physiological conditions) and the cell mineralization-stimulating effect of biosilica. However, so far immobilization of silicatein has been hampered by the complex multistep procedure required. In addition, the chemical surface modific…
Functional biohybrid materials based on halloysite, sepiolite and cellulose nanofibers for health applications
2019
Biohybrid materials were prepared by co-assembling the three following components: nanotubular halloysite, microfibrous sepiolite, and cellulose nanofibers dispersed in water, in order to exploit the most salient features of each individual component and to render homogeneous, flexible, yet strong films. Indeed, the incorporation of halloysite improves the mechanical performance of the resulting hybrid nanopapers and the assembly of the three components modifies the surface features concerning wetting properties compared to pristine materials, so that the main characteristics of the resulting materials become tunable with regard to certain properties. Owing to their hierarchical porosity to…
Polycaprolactone/gelatin-based scaffolds with tailored performance: in vitro and in vivo validation
2019
Abstract Nanofibrous scaffolds composed of polycaprolactone (PCL) and gelatin (Ge) were obtained through a hydrolytic assisted electrospinning process. The PCL-to-Ge proportion (100/0 to 20/80), as well as the dissolution time (24, 48, 72, 96, 120 h) into a 1:1 formic/acetic acid solvent before electrospinning were modified to obtain the different samples. A strong influence of these factors on the physicochemical properties of the scaffolds was observed. Higher Ge percentage reduced crystallinity, allowed a uniform morphology and increased water contact angle. The increase in the dissolution time considerably reduced the molar mass and, subsequently, fibre diameter and crystallinity were a…
Programmable assembly of peptide amphiphile via noncovalent-to-covalent bond conversion
2017
Controlling the number of monomers in a supramolecular polymer has been a great challenge in programmable self-assembly of organic molecules. One approach has been to make use of frustrated growth of the supramolecular assembly by tuning the balance of attractive and repulsive intermolecular forces. We report here on the use of covalent bond formation among monomers, compensating for intermolecular electrostatic repulsion, as a mechanism to control the length of a supramolecular nanofiber formed by self-assembly of peptide amphiphiles. Circular dichroism spectroscopy in combination with dynamic light scattering, size-exclusion chromatography, and transmittance electron microscope analyses r…
Controlled Release of Metformin Hydrochloride from Core-Shell Nanofibers with Fish Sarcoplasmic Protein
2019
Ficai, Anton/0000-0002-1777-0525; Karademir, Betul/0000-0003-1762-0284 WOS:000503463400074 PubMed ID: 31658758 Background and Objectives: A coaxial electrospinning technique was used to produce core/shell nanofibers of a polylactic acid (PLA) as a shell and a polyvinyl alcohol (PVA) containing metformin hydrochloride (MH) as a core. Materials and Methods: Fish sarcoplasmic protein (FSP) was extracted from fresh bonito and incorporated into nanofiber at various concentrations to investigate the influence on properties of the coaxial nanofibers. The morphology, chemical structure and thermal properties of the nanofibers were studied. Results: The results show that uniform and bead-free struct…
Ellipsoid-shaped superparamagnetic nanoclusters through emulsion electrospinning.
2015
Ellipsoid-shaped nanoclusters composed of single superparamagnetic nanoparticles can be generated by emulsion electrospinning. Stretching and subsequent solvent evaporation of iron oxide loaded emulsion droplets during the emulsion electrospinning process enables the creation of such structures embedded in polymer nanofibers. Dissolution of the polymer fibers yields an aqueous dispersion of the inorganic clusters which are the first example of ellipsoid-shaped superparamagnetic nanoclusters with a high saturation magnetization (∼47 emu g(-1)).
Positional Isomers of Chromophore–Peptide Conjugates Self-Assemble into Different Morphologies
2018
Ordering π-systems into defined supramolecular structures is important for the development of organic functional materials. In recent years, peptides with defined secondary structures and/or self-assembly properties were introduced as powerful tools to order peptide-chromophore conjugates into different morphologies. This work explores whether or not the directionality of peptides can be used to control the self-assembly. The position of the π-system in conjugates between oligoprolines and perylene monoimide (PMI) chromophores was varied by attaching the PMI moiety to the second-to-last residue from the C- and N-termini, respectively. Microscopic and diffraction analysis revealed that the p…