scholarly journals Preliminary Biocompatibility Tests of Poly-ε-Caprolactone/Silver Nanofibers in Wistar Rats

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1135
Author(s):  
Oskar Álvarez-Ortega ◽  
Luis Roberto Ruiz-Ramírez ◽  
Jesús Alberto Garibay-Alvarado ◽  
Alejandro Donohue-Cornejo ◽  
León Francisco Espinosa-Cristóbal ◽  
...  
Keyword(s):  
Wistar Rats ◽  
Inflammatory Infiltrate ◽  
Subcutaneous Tissue ◽  
Average Diameter ◽  
Dark Field ◽  
Electrospinning Technique ◽  
Multinucleated Cells ◽  
X Ray Scattering ◽  
Good Healing

Currently, nanotechnology is perceived as a promising science that produces materials with diverse unique properties at a nanometric scale. Biocompatibility tests of poly-ε-caprolactone nanofibers, embedded with silver nanoparticles manufactured by means of the electrospinning technique, were carried out in Wistar rats to be used as oral dressings for the eradication of bacteria. Solutions of 12.5, 25, 50 and 100 mM of silver nitrate were made using N-dimethylformamide (DMF) and tetrahydrofuran (THF) as reducing solvents with 8% of poly-ε-caprolactone (PCL) polymer. The solutions were electrospun, and the nanofibers obtained in the process were characterized by infrared spectroscopy, Raman spectroscopy, dark field optical microscopy, scanning electron microscopy and X-ray scattering spectroscopy. The nanofibers had an average diameter of 400 ± 100 nm. Once the characterization of the material was done, three implants of each concentration of the nanofibers were formed and placed in the subcutaneous tissue of the rats. Three experimental subjects were used, leaving the material in them for a length of two, four and six weeks, respectively. The rats showed good healing, with the lesions completely healed at four weeks after implantation. After that time, biopsies were taken, and histopathological sections were made to evaluate the inflammatory infiltrate. The tissues of the rats presented chronic inflammatory infiltrate composed mainly of lymphocytes and giant multinucleated cells. The material was rejected by the rats when a layer of collagen and fibroblasts was produced, coating the material, a process characteristic of a foreign body reaction.

scholarly journals Synthesis and mechanical characterization of a non-woven nanofiber by the electrospinning technique

DYNA ◽  
2019 ◽  
Vol 86 (209) ◽  
pp. 64-72
Author(s):  
Edwin Edgardo Espinel Blanco ◽  
Nelson Escobar-Mora ◽  
Lina Marcela Hoyos-Palacio ◽  
Martin Fabián Sarmiento-Gaviria
Keyword(s):  
Electron Microscopy ◽  
Mechanical Characterization ◽  
Average Diameter ◽  
Electrospinning Technique ◽  
Acid Ratio ◽  
Nanostructured Polymer ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Scanning Electron

A non-woven nanofiber or polymeric cover is synthesized with nylon-6 as the base polymeric material. Different acid relationships (formic/acetic) were tested in the electrospinning equipment, until defining by macroscopic observations and SEM Scanning Electron Microscopy analysis the adequate acid ratio 3:2 and the average diameter of the nanofibers in 350nm, defining the parameters to operate the electrospinning. According to ASTM D 882 standard, the Tensile Strength was calculated for stresses applied horizontally and vertically to the direction of the nanofibers. With the standards ASTM D 7490 and ASTM G-15 the wettability was determined by measuring the contact angle, finding that it has hydrophilic properties with high wettability, adhesiveness and surface energy. Nanostructured polymer covers can be used for biological isolation in health care areas, as a protective barrier to control the spread of infections. 

Fabrication and Optical Characterization of Silicon Carbide Nanofibers

2007 ◽  
Vol 1006 ◽  
Author(s):  
Saima Khan ◽  
Aurangzeb Khan ◽  
Martin E. Kordesch
Keyword(s):  
Silicon Carbide ◽  
Polyethylene Oxide ◽  
Average Diameter ◽  
Main Peak ◽  
X Ray Diffraction ◽  
Electrospinning Technique ◽  
X Ray ◽  
Broad Emission ◽  
Infrared Spectral

AbstractSilicon Carbide (SiC) nanofibers were synthesized from SiC powder dispersed in polyethylene oxide (PEO) solution in Chloroform using the electrospinning technique. The as-spun fibers were then annealed at 1000ËC to 7 hours. The average diameter of the annealed fibers is 500 nm while the length of the annealed fibers is about 50 µm. The fibers were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD) and Cathodoluminescence (CL). PL spectra from the annealed SiC fibers show a broad emission in the red-infrared spectral regime. The main peak is centered at 774 nm while the shoulder on the left is at 740 nm

Preparation and Characterization of Sandwich Structure Purification Material via Gas-Jet/Electrospinning Technique

2012 ◽  
Vol 531 ◽  
pp. 14-18
Author(s):  
Tai Qi Liu ◽  
Bin Bin Cao ◽  
Xiao Long Zhao ◽  
Chen Wang ◽  
Ruo Fan Zhang ◽  
...  
Keyword(s):  
Sandwich Structure ◽  
Electrospun Nanofibers ◽  
Average Diameter ◽  
Antibacterial Activities ◽  
Nano Particles ◽  
Gas Jet ◽  
Nano Tio2 ◽  
Electrospinning Technique ◽  
High Efficient

Nano-TiO2 is a high efficient and no poisonous light induced catalyst. It is important how to immobilize it on some supporter for its application. In this paper, The Nylon-6 (PA-6) nanofibres bearing TiO2 nano-particles were prepared via gas-jet/electrospinning technique. The resulted materials were characterized by XRD, SEM, TEM, EDX and TG techniques, and antibacterial activities of the resulted fibers were tested by Shake Flask method. The results show that fibers bearing nano-TiO2, in an average diameter from 60 to 65nm were prepared, and the antibacterial efficiency of these gas-jet/electrospun nanofibers can reach 99.74%. The titled fibers can be loaded in a sandwich structure nanofiber super-cleaning material by hot-press process, and its filtration efficiency can reach 99.50% with 1µm polystyrene microspheres as the filter media.

Fabrication and Characterization of Cellulose Acetate Nanofibers

2014 ◽  
Vol 1030-1032 ◽  
pp. 78-81
Author(s):  
Zainal Anisah ◽  
Naznin Sultana ◽  
Mohammed Rafiq Abdul Kadir
Keyword(s):  
Acetic Acid ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Morphological Structure ◽  
Average Diameter ◽  
Solvent System ◽  
Electrospinning Technique ◽  
Fabrication And Characterization ◽  
Scanning Electron

In this study, CA fibers were fabricated using electrospinning technique with the mixture of acetic acid/acetone as the solvent system with the ratio of 3:1. The morphological structure of the fibers obtained was observed using scanning electron microscope (SEM). The SEM results showed that 10% of CA produced beads only, 12% of CA produced spindle beads with few fibers, 13% of CA produced fibers with few beads and 14% w/v concentration of CA produced continuous and smooth ribbon-like fibers with average diameter of 199.23nm.

Imaging of platinum-shadowed macromolecular complexes in dark field

1984 ◽  
Vol 42 ◽  
pp. 146-147
Author(s):  
D.W. Andrews ◽  
F.P. Ottensmeyer
Keyword(s):  
Thin Film ◽  
Three Dimensional ◽  
Average Diameter ◽  
Dark Field ◽  
Bright Field ◽  
Field Mode ◽  
Macromolecular Complexes ◽  
Average Mass ◽  
Topological Features ◽  
Projection Images

Shadowing with heavy metals has been used for many years to enhance the topological features of biological macromolecular complexes. The three dimensional features present in directionaly shadowed specimens often simplifies interpretation of projection images provided by other techniques. One difficulty with the method is the relatively large amount of metal used to achieve sufficient contrast in bright field images. Thick shadow films are undesirable because they decrease resolution due to an increased tendency for microcrystalline aggregates to form, because decoration artefacts become more severe and increased cap thickness makes estimation of dimensions more uncertain.The large increase in contrast provided by the dark field mode of imaging allows the use of shadow replicas with a much lower average mass thickness. To form the images in Fig. 1, latex spheres of 0.087 μ average diameter were unidirectionally shadowed with platinum carbon (Pt-C) and a thin film of carbon was indirectly evaporated on the specimen as a support.

Characterization of frozen hydrated biological specimens by low-loss EELS

1992 ◽  
Vol 50 (2) ◽  
pp. 1572-1573
Author(s):  
Songquan Sun ◽  
Richard D. Leapman
Keyword(s):  
Water Content ◽  
Direct Method ◽  
Internal Standard ◽  
Dry Weight ◽  
Dark Field ◽  
Protein Solutions ◽  
Subcellular Compartment ◽  
Differential Shrinkage ◽  
Electron Energy Loss

Analyses of ultrathin cryosections are generally performed after freeze-drying because the presence of water renders the specimens highly susceptible to radiation damage. The water content of a subcellular compartment is an important quantity that must be known, for example, to convert the dry weight concentrations of ions to the physiologically more relevant molar concentrations. Water content can be determined indirectly from dark-field mass measurements provided that there is no differential shrinkage between compartments and that there exists a suitable internal standard. The potential advantage of a more direct method for measuring water has led us to explore the use of electron energy loss spectroscopy (EELS) for characterizing biological specimens in their frozen hydrated state.We have obtained preliminary EELS measurements from pure amorphous ice and from cryosectioned frozen protein solutions. The specimens were cryotransfered into a VG-HB501 field-emission STEM equipped with a 666 Gatan parallel-detection spectrometer and analyzed at approximately −160 C.

Biopolymers with Medical Applications Optimized method for obtaining chitosan-based delivery systems

2018 ◽  
Vol 69 (7) ◽  
pp. 1756-1759 ◽  
Author(s):  
Luminita Confederat ◽  
Iuliana Motrescu ◽  
Sandra Constantin ◽  
Florentina Lupascu ◽  
Lenuta Profire
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Average Diameter ◽  
Delivery Systems ◽  
Cross Linking ◽  
Low Molecular Weight ◽  
Polymeric Systems ◽  
Chitosan Microparticles ◽  
Degree Of Swelling

The aim of this study was to optimize the method used for obtaining microparticles based on chitosan � a biocompatible, biodegradable, and nontoxic polymer, and to characterize the developed systems. Chitosan microparticles, as drug delivery systems were obtained by inotropic gelation method using pentasodiumtripolyphosphate (TPP) as cross-linking agent. Chitosan with low molecular weight (CSLMW) in concentration which ranged between 0.5 and 5 %, was used while the concentration of cross-linking agent ranged between 1 and 5%. The characterization of the microparticles in terms of shape, uniformity and adhesion was performed in solution and dried state. The size of the microparticles and the degree of swelling were also determined. The structure and the morphology of the developed polymeric systems were analyzed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).The average diameter of the chitosan microparticles was around 522 �m. The most stable microparticles were obtained using CSLMW 1% and TPP 2% or CSLMW 0.75%and TPP 1%. The micropaticles were spherical, uniform and without flattening. Using CSLMW in concentration of 0.5 % poorly cross-linked and crushed microparticles have been obtained at all TPP concentrations. By optimization of the method, stable chitosan-based micropaticles were obtained which will be used to develop controlled release systems for drug delivery.

Isolasi Dan Karakterisasi Bentonit Alam Menjadi Nanopartikel Monmorillonit

2018 ◽  
Vol 3 (1) ◽  
pp. 12 ◽  
Author(s):  
Zaimahwati Zaimahwati ◽  
Yuniati Yuniati ◽  
Ramzi Jalal ◽  
Syahman Zhafiri ◽  
Yuli Yetri
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Surface Morphology ◽  
Average Diameter ◽  
Particle Size Analyzer ◽  
Ft Ir ◽  
Scanning Electron ◽  
Sedimentation Processes

<p>Pada penelitian ini telah dilakukan isolasi dan karakterisasi bentonit alam menjadi nanopartikel montmorillonit. Bentonit alam yang digunakan diambil dari desa Blangdalam, Kecamatan Nisam Kabupaten Aceh Utara.  Proses isolasi meliputi proses pelarutan dengan aquades, ultrasonic dan proses sedimentasi. Untuk mengetahui karakterisasi montmorillonit dilakukan uji FT-IR, X-RD dan uji morfologi permukaan dengan Scanning Electron Microscopy (SEM). Partikel size analyzer untuk menganalisis dan menentukan ukuran nanopartikel dari isolasi bentonit alam. Dari hasil penelitian didapat ukuran nanopartikel montmorillonit hasil isolasi dari bentonit alam diperoleh berdiameter rata-rata 82,15 nm.</p><p><em>In this research we have isolated and characterized natural bentonite into montmorillonite nanoparticles. Natural bentonite used was taken from Blangdalam village, Nisam sub-district, North Aceh district. The isolation process includes dissolving process with aquades, ultrasonic and sedimentation processes.  The characterization of montmorillonite, FT-IR, X-RD and surface morphology test by Scanning Electron Microscopy (SEM). Particle size analyzer to analyze and determine the size of nanoparticles from natural bentonite insulation. From the research results obtained the size of montmorillonite nanoparticles isolated from natural bentonite obtained an average diameter of 82.15 nm.</em></p>

Small angle X-ray scattering study of porosity variation in a styrene-divinylbenzene copolymer

1981 ◽  
Vol 46 (7) ◽  
pp. 1675-1681 ◽  
Author(s):  
Josef Baldrian ◽  
Božena N. Kolarz ◽  
Henrik Galina
Keyword(s):  
Small Angle ◽  
Structural Parameters ◽  
Two Phase ◽  
X Ray ◽  
Porosity Variation ◽  
Swelling Agent ◽  
X Ray Scattering ◽  
Styrene Divinylbenzene ◽  
Ray Scattering

Porosity variations induced by swelling agent exchange were studied in a styrene-divinylbenzene copolymer. Standard methods were used in the characterization of copolymer porosity in the dry state and the results were compared with related structural parameters derived from small angle X-ray scattering (SAXS) measurements as developed for the characterization of two-phase systems. The SAXS method was also used for porosity determination in swollen samples. The differences in the porosity of dry samples were found to be an effect of the drying process, while in the swollen state the sample swells and deswells isotropically.

First characterization of chemical environments using energy dispersive inelastic x-ray scattering induced by an x-ray tube

2021 ◽  
Vol 92 (1) ◽  
pp. 013102
Author(s):  
Roberto Daniel Pérez ◽  
Juan José Leani ◽  
José Ignacio Robledo ◽  
Héctor Jorge Sánchez
Keyword(s):  
Energy Dispersive ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering
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