scholarly journals Characterization and Release Behavior of a Thiosemicarbazone from Electrospun Polyvinyl Alcohol Core-Shell Nanofibers

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1488
Author(s):  
Hossein Barani ◽  
Mohsen Khorashadizadeh ◽  
Alexander Haseloer ◽  
Axel Klein
Keyword(s):  
Polyvinyl Alcohol ◽  
Inhibitory Concentration ◽  
Diffusion Mechanism ◽  
Antibacterial Properties ◽  
Electrospinning Process ◽  
Attenuated Total Reflection ◽  
Core Shell ◽  
Fiber Mats ◽  
Best Fit ◽  
Chemical Integrity

Mats of polyvinyl alcohol (PVA) core–shell nanofibers were produced using coaxial electrospinning in the presence of a thiosemicarbazone (TSC) N4-(S)-1-phenylethyl)-2-(pyridin-2-yl-ethylidene)hydrazine-1-carbothioamide (HapyTSCmB). Monolithic fibers with 0% or 5% TSC and core–shell fibers with 10% TSC in the spinning solution were studied to compare stability and release rates. SEM showed the formation of uniform, bead-free, cylindrical, and smooth fibers. NMR spectroscopy and thermal analysis (TG/DTA) gave proof for the chemical integrity of the TSC in the fiber mats after the electrospinning process. Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy showed no TSC on the surface of the PVA/TSC-PVA fibers confirming the core–shell character. The TSC release profiles of the fibers as studied using UV-vis absorption spectroscopy showed a slower release from the PVA/TSC-PVA core–shell structure compared with the monolithic PVA/TSC fibers as well as lower cumulative release percentage (17%). Out of several release models, the Korsmeyer–Peppas model gave the best fit to the experimental data. The main release phase can be described with a Fick-type diffusion mechanism. Antibacterial properties were tested against the Gram-positive Staphylococcus aureus bacterium and gave a minimal inhibitory concentration of 12.5 μg/mL. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazoliumbromide (MTT)-based cytotoxicity experiments showed that the cell viability of fibroblast at different contents of TSC was slightly decreased from 1.5% up to 3.5% when compared to control cells.

Preparation of Polytetrafluoroethylene Ultrafine Fiber Mats with Electrospinning Process

2011 ◽  
Vol 675-677 ◽  
pp. 827-830 ◽  
Author(s):  
Si Jun Zhu ◽  
Yuan Yuan Zhou ◽  
Ochi Takashi ◽  
Gang Wu
Keyword(s):  
Heat Treatment ◽  
Fourier Transform ◽  
Electrospinning Process ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Poly Vinyl Alcohol ◽  
Mass Ratio ◽  
Fiber Mats ◽  
Ultrafine Fibers ◽  
Ultrafine Fiber

Polytetrafluoroethylene (PTFE) ultrafine fibers mats were prepared by electrospinning of an aqueous PTFE dispersion and a small amount of poly(vinyl alcohol) (PVA) and subsequent heat-treatment. The influence of dispersions composition on the morphology of fabricated PTFE ultrafine fiber mats was investigated. The fabricated mats were characterized by attenuated total reflection-Fourier transform infrared (ATR-FTIR) and koniology tester. The results show that the PVA/PTFE mass ratio of 1:5 was suitable for the PTFE fibers formation. All the PVA in the electrospun PVA/PTFE mats was removed at 350 °C~390°C. The fabricated PTFE ultrafine fiber mats have the potential to be used as high-temperature filter.

scholarly journals Fabrication and Sustained Release of Chlorogenic Acid from Poly(vinyl alcohol)/Poly(γ-glutamic Acid) Blends Electrospun Mats

2020 ◽  
Author(s):  
I. E. Sandova-Herrera ◽  
A. Ledezma-Pérez ◽  
A. De-León ◽  
C. Alvaro-Canche ◽  
R. Torres-Lubian ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Glutamic Acid ◽  
Chlorogenic Acid ◽  
Diabetic Foot ◽  
Release Kinetics ◽  
Electrospun Fiber ◽  
Diffusion Mechanism ◽  
Poly Vinyl Alcohol ◽  
Fiber Mats

Abstract Background: Diabetic foot is a condition that is caused by high levels of glucose in the blood. Poly (γ-glutamic acid) [γ-PGA]/polyvinyl alcohol [PVA] electrospun biopolymers and their use in the release of chlorogenic acid (CGA) is a promising system, thanks to their biocompatibility and the use of (CGA) in the treatment of certain symptoms of diabetic conditions. The use of CGA was reported in 2005 as a capable substance in the treatment of lesions caused by diabetic foot ulcers, thanks to the fact that it has no toxic effects.Methods: In this work, was carried out the bio-synthesis of γ-PGA producing by the Bacillus liqueniformis ATCC-9945a. This material was utilized in the preparation of electrospun nanofibers with solutions of polyvinyl alcohol [PVA] to 10% p/v mixed with γ-PGA to 5 and 10% p/v. These solutions were loaded with chlorogenic acid (CGA) like an active hypoglycemic agent.Results: The morphological analysis shows a size decrease for the fiber with PVA/ γ -PGA, compared to PVA nanofibers; this could be attributed to the hydrogen bonding interactions between γ-PGA and PVA. The use of glutaraldehyde vapors permit the nanofibers crosslinking to maintain a stable structure and allows the CGA release. The in vitro release analysis shows that the PVA membranes reach 28% of delivery after the first 24 hours. Instead of, for the nanofiber mat with PVA blended with γ-PGA at 5% goes up to 57% and nanofiber PVA/γ-PGA at 10% reach to 66% in the same time, the rate constant for release kinetics shows that PVA/γ-PGA at 5% it's higher than the others, being the first in reach the saturation.Conclusions: Biodegradable polymer meshes were fabricated by electrospinning of PVA and PVA/γ-PGA polymer and loaded with CGA. The presence of γ-PGA into PVA solutions increases the in vitro drug release from electrospun fiber mats. The maximal release of CGA was reached at 10% of γ-PGA introduced in the PVA solution, which was 82% release from the electrospun polymer fiber mats. Finally, the use of Peppas and Weibull models indicates the released kinetics of CGA from PVA, PVA/γ-PGA 5, and PVA/γ-PGA 10 electrospun fiber mats are driven by diffusion mechanism.

The Formation and Morphology of PVA Ferrogel Nanofibre by the Electrospinning Process

2010 ◽  
Vol 650 ◽  
pp. 361-366 ◽  
Author(s):  
Tao Yu Wan ◽  
Mohammad Chowdhury ◽  
George K. Stylios
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polyvinyl Alcohol ◽  
Flow Rate ◽  
Electrospinning Process ◽  
Magnetic Sensors ◽  
Solution Flow Rate ◽  
Solution Flow ◽  
Fiber Mats ◽  
Scanning Electron

Aqueous solutions of polyvinyl alcohol (PVA) with FeCl3 were homogenously mixed and subsequently electrospun; and its characteristics were studied as a function of voltage, tip-target distance and solution flow rate. Fiber mats of (PVA)/FeCl3 composite, in the diameter of 700–1100 nm were prepared by electrospinning. Lower concentrations of solution tended to facilitate the formation of fibres with beads. With increasing concentration, the morphology was improved with smooth and uniform fibres and the increased fibre diameters in the nano range. Spinning voltage also had an important influence on the diameters of the nano fibres, while the collection distance affected fibre diameters. Nano fibres of smaller diameter were formed when lower voltages are applied. The morphology of the electrospun from PVA/FeCl3 nano fibres and their magnetic power was observed and analyzed by scanning electron microscopy (SEM).The fibres produced in this way could potentially be applied to manufacture magnetic sensors, flexible magnets.

scholarly journals Electrospun Janus Beads-On-A-String Structures for Different Types of Controlled Release Profiles of Double Drugs

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 635
Author(s):  
Ding Li ◽  
Menglong Wang ◽  
Wen-Liang Song ◽  
Deng-Guang Yu ◽  
Sim Wan Annie Bligh
Keyword(s):  
Controlled Release ◽  
Combined Therapy ◽  
Diffusion Mechanism ◽  
Amorphous State ◽  
Electrospinning Process ◽  
Fickian Diffusion ◽  
In Vitro Dissolution ◽  
Sem Images ◽  
Release Profiles

A side-by-side electrospinning process characterized by a home-made eccentric spinneret was established to produce the Janus beads-on-a-string products. In this study, ketoprofen (KET) and methylene blue (MB) were used as model drugs, which loaded in Janus beads-on-a-string products, in which polyvinylpyrrolidone K90 (PVP K90) and ethyl cellulose (EC) were exploited as the polymer matrices. From SEM images, distinct nanofibers and microparticles in the Janus beads-on-a-string structures could be observed clearly. X-ray diffraction demonstrated that all crystalline drugs loaded in Janus beads-on-a-string products were transferred into the amorphous state. ATR-FTIR revealed that the components of prepared Janus nanostructures were compatibility. In vitro dissolution tests showed that Janus beads-on-a-string products could provide typical double drugs controlled-release profiles, which provided a faster immediate release of MB and a slower sustained release of KET than the electrospun Janus nanofibers. Drug releases from the Janus beads-on-a-string products were controlled through a combination of erosion mechanism (linear MB-PVP sides) and a typical Fickian diffusion mechanism (bead KET-EC sides). This work developed a brand-new approach for the preparation of the Janus beads-on-a-string nanostructures using side-by-side electrospinning, and also provided a fresh idea for double drugs controlled release and the potential combined therapy.

Surface Separation Equilibria and Dynamics of Cationic Dye Loaded onto Citric Acid and Sodium Hydroxide Treated Eggshells

2018 ◽  
Vol 17 (1) ◽  
Author(s):  
Elisha A. Adeniji ◽  
Temitope O. Abodunrin ◽  
Temitope A. Ogunnupebi ◽  
Babatunde A. Koiki ◽  
Abimbola M. Olatunde ◽  
...  
Keyword(s):  
Citric Acid ◽  
Diffusion Mechanism ◽  
Experiment Data ◽  
Surface Separation ◽  
Rate Limiting Step ◽  
Monolayer Adsorption ◽  
Delta G ◽  
Rate Limiting ◽  
Best Fit ◽  
Adsorption Systems

AbstractThis research enthusiastically highlights the bio-adsorption of methylene blue (MB) by local, poultry, NaOH and citric acid modified ubiquitous eggshell (LES, NLES, CLES, PES, NPES and CPES) adsorbents. The microstructures of these adsorbents indicated that they had some surface functional moieties that were responsible for the adsorption of MB. The Langmuir isotherm and PSO model best fit the experiment data. The largest Langmuir monolayer adsorption capacity${q_{max}}$, was 242.47 mg/g, with the largest MB initial concentration of 400 mg/L. This was a clear indication and a confirmation that MB adsorption by the powdered eggshells was chemisorptive. Moreover, the values of$F$, the thickness of the boundary layer/film were$\gt 0$, showing that the rate limiting step for the adsorption process was controlled by more than one diffusion mechanism. The values of$\Delta {G^\circ }$for the adsorption of MB by the adsorbents indicated that the adsorption reactions were all non-feasible and non-spontaneous. The values for$\Delta {S^\circ }$(J/K/mol) for LES, NLES and CPES for the uptake of MB showed decrease in the chaos or degree of randomness of the adsorption reactions, and the reverse was the case for PES, NPES and CLES for the uptake of MB, which showed increase in the chaos or degree of randomness of the adsorption. The adsorption of MB by LES, NLES and CPES gave$\Delta {H^\circ }$(kJ/mol) values which were indicative of endothermic nature of the adsorption systems, and the reverse was the case for the uptake of MB by PES, NPES and CLES, which was indicative of the exothermic nature of the adsorption systems.

scholarly journals Synthesis and Characterization of a Bioartificial Polymeric System with Potential Antibacterial Activity: Chitosan-Polyvinyl Alcohol-Ampicillin

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3109 ◽  
Author(s):  
Andres Bernal-Ballen ◽  
Jorge Lopez-Garcia ◽  
Martha-Andrea Merchan-Merchan ◽  
Marian Lehocky
Keyword(s):  
Antibacterial Activity ◽  
Polyvinyl Alcohol ◽  
Statistical Significance ◽  
Antibacterial Properties ◽  
Intermolecular Forces ◽  
Polymeric System ◽  
Bacterial Strains ◽  
Natural Polymers ◽  
The Matrix ◽  
The Individual

Bio-artificial polymeric systems are a new class of polymeric constituents based on blends of synthetic and natural polymers, designed with the purpose of producing new materials that exhibit enhanced properties with respect to the individual components. In this frame, a combination of polyvinyl alcohol (PVA) and chitosan, blended with a widely used antibiotic, sodium ampicillin, has been developed showing a moderate behavior in terms of antibacterial properties. Thus, aqueous solutions of PVA at 1 wt.% were mixed with acid solutions of chitosan at 1 wt.%, followed by adding ampicillin ranging from 0.3 to 1.0 wt.% related to the total amount of the polymers. The prepared bio-artificial polymeric system was characterized by FTIR, SEM, DSC, contact angle measurements, antibacterial activity against Staphylococcus aureus and Escherichia coli and antibiotic release studies. The statistical significance of the antibacterial activity was determined using a multifactorial analysis of variance with ρ < 0.05 (ANOVA). The characterization techniques did not show alterations in the ampicillin structure and the interactions with polymers were limited to intermolecular forces. Therefore, the antibiotic was efficiently released from the matrix and its antibacterial activity was preserved. The system disclosed moderate antibacterial activity against bacterial strains without adding a high antibiotic concentration. The findings of this study suggest that the system may be effective against healthcare-associated infections, a promising view in the design of novel antimicrobial biomaterials potentially suitable for tissue engineering applications.

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