Fabrication and characterization of bactericidal thiol-chitosan and chitosan iodoacetamide nanofibres (original) (raw)
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Healing performance of wound dressing from cyanoethyl chitosan electrospun fibres
Chitosan-based structures with high surface area have been developed for their application in wound dressings. In such structures, the next to skin layer is chitosan-based nanofibre formed by electrospinning technique. Chitosan derivatives have been synthesized and electrospinning trials of their solutions are conducted using different electrospinning parameters such as polymer concentration in electrospinning solution, solution feed rate and electrical field strength. Contact kill performance of the electrospun structures against a range of microbes is studied using the disc diffusion method. The results indicate that the developed nanofibre webs exhibit an excellent antimicrobial behavior.
Chitosan–bacterial nanocellulose nanofibrous structures for potential wound dressing applications
Cellulose, 2016
The fabrication of nonwoven mats containing chitosan and bacterial nanocellulose by electrospinning were considered using two different approaches: (1) simultaneous spinning of chitosan and bacterial nanocellulose solutions using two separate syringes towards the same target and (2) coaxial electrospinning, where chitosan and bacterial nanocellulose were simultaneously electrospun through a spinneret composed of two concentric needles to produce core-shell structures. Co-spinning agents were required in both approaches. A direct blend of chitosan and bacterial nanocellulose and subsequent electrospinning was not feasible due to the incompatibility of their respective solvents. The first approach led to the production of mats containing both chitosan and bacterial nanocellulose nanofibers. However, few bacterial nanocellulose fibers were deposited on the collector. Addition of polylactide as a co-spinning agent and an increase in solution temperature (from 22 to 60°C) during electrospinning was required to improve both fiber formation and collection. On the other hand, coaxial electrospinning showed the best results for the production of nanofibers containing both chitosan and bacterial nanocellulose. Nanofibers with a good yield were obtained by using a chitosan/ poly(ethylene oxide) (2.4/0.6 wt/v%) aqueous solution as the inner layer, and a bacterial nanocellulose solution (0.6 wt/v%) as the outer layer. Co-electrospun nanofibers had a diameter of 85 nm in average, and a narrow size distribution. The core/shell nanostructure was validated by transmission electron microscopy whilst energy-dispersive X-ray spectroscopy analysis showed that the nanofibers contained both chitosan and bacterial nanocellulose along their structure. Finally, the mats obtained by the coaxial approach exhibited strong antimicrobial activity with a decrease of 99.9 % of an Escherichia coli population.
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Macromolecular Bioscience, 2013
Chitosan is non-toxic, biocompatible, and biodegradable polysaccharide from renewable resources, known to have inherent antibacterial activity, which is mainly due to its polycationic nature. The combining of all assets of chitosan and its derivatives with the unique properties of electrospun nanofibrous materials is a powerful strategy to prepare new materials that can find variety of biomedical applications. In this article the most recent studies on different approaches for preparation of antibacterial fibrous materials from chitosan and its derivatives such as electrospinning, coating, and electrospinning-electrospraying, loading of drugs or bioactive nanoparticles are summarized.
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Microporous chitosan nanofibers functionalized with different amounts of an antimicrobial agent via imine linkage were prepared by a three-step procedure including the electrospinning of a chitosan/PEO blend, PEO removal and acid condensation reaction in a heterogeneous system with 2-formylphenylboronic acid. The fibers’ characterization was undertaken keeping in mind their application to wound healing. Thus, by FTIR and 1H-NMR spectroscopy, it was confirmed the successful imination of the fibers and the conversion degree of the amine groups of chitosan into imine units. The fiber morphology in terms of fiber diameter, crystallinity, inter- and intra-fiber porosity and strength of intermolecular forces was investigated using scanning electron microscopy, polarized light microscopy, water vapor sorption and thermogravimetric analysis. The swelling ability was estimated in water and phosphate buffer by calculating the mass equilibrium swelling. The fiber biodegradation was explored in...
Antibacterial Fibers Based on Cellulose and Chitosan
Contemporary Materials, 2013
Cellulose and chitin are the most abundant polysaccharides in nature. Chitin is the natural amino polysaccharide and is estimated to be produced annually almost as much as cellulose. These resources are renewable and inexhaustible if rationally utilised. Unique properties of chitin and chitosan (chitin derivative obtained by the deacetylation of chitin), such as antibacterial activity, biocompatibility, non-toxicity and bioresorptivity make these materials very suitable and important biomaterials. During our studies, we examined the possibilities of obtaining composite, biologically active cellulose-chitosan fibres. Аn effective two-stage procedure for obtaining antibacterial fibers based on cellulose and chitosan was developed. The first stage involves the formation of dialdehyde cellulose by potassium periodate oxidation of cellulose fibers, which is able to form Schiff's base with chitosan. In the second stage, chitosan coated cellulose fibers were prepared by subsequent treatment of oxidized cellulose fibers with a solution of chitosan in aqueous acetic acid. Maximum percentage of chitosan introduced into/onto the cellulose fibers was 0,51 % (w/w). Antibacterial activity of cellulose fibers coated with chitosan as the active component against bacteria Escherichia coli and Staphylococcus aureus, was confirmed by in vitro experiments.
Materials, 2021
This research proposed two pretreatments of viscose fabrics: oxidation with 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO) and coating with TEMPO-oxidized cellulose nanofibrils (TOCN), to introduce functional groups (COOH and CHO) suitable for irreversible binding of chitosan nanoparticles without and with embedded zinc (NCS and NCS + Zn, respectively) and consequently achieving washing durable antibacterial properties of the chitosan nanoparticles functionalized fabrics. The characterizations of pretreated and chitosan nanoparticles functionalized fabrics were performed by FTIR and XPS spectroscopy, elemental analysis, inductively coupled plasma optical emission spectrometry, zeta potential measurements, scanning electron microscopy, determination of COOH and CHO groups content, and antimicrobial activity under dynamic contact conditions. Influence of pretreatments on NCS and NCS + Zn adsorption, chemical, electrokinetic, and antibacterial properties as well as morphology, and...
Materials
The interest in wound healing characteristics of bioactive constituents and therapeutic agents, especially natural compounds, is increasing because of their therapeutic properties, cost-effectiveness, and few adverse effects. Lately, nanocarriers as a drug delivery system have been actively investigated and applied in medical and therapeutic applications. In recent decades, researchers have investigated the incorporation of natural or synthetic substances into novel bioactive electrospun nanofibrous architectures produced by the electrospinning method for skin substitutes. Therefore, the development of nanotechnology in the area of dressings that could provide higher performance and a synergistic effect for wound healing is needed. Natural compounds with antimicrobial, antibacterial, and anti-inflammatory activity in combination with nanostructured fibers represent a future approach due to the increased wound healing process and regeneration of the lost tissue. This paper presents d...
Chitosan based fibers embedding carbon dots with anti‐bacterial and fluorescent properties
Polymer Composites, 2020
Due to the intriguing properties of Chitosan (CS), many efforts have been paid for CS-based fiber preparation. As it is impossible to prepare CS fiber directly, facilitating polymers such as polyvinyl alcohol (PVA) possessing necessary properties that enable CS-based fiber fabrication is used. For this purpose, 3 wt % of CS in 90% acetic acid solution and 6 wt% PVA solution in DI water used in CS/PVA fiber preparation at different proportions for example, 2:1, 9:1 and 10:1 by weight to fabricate fibers by electrospinning method. Furthermore, to render fluorescent property to CS/PVA (9:1) fibers, N-doped carbon dots (C-dots) added into fiber precursor during fiber preparation. The emission peak of C-dots based fibers that with fluorescent features was observed at around 436 nm. The morphological, structural and, thermal characterizations of CS-based fibers were done with scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analyzer, respectively. Anti-bacterial activity of bare CS/PVA was increased with the increase in amounts of C-dots embedding. The inhibition of zone of CS/PVA (9:1) fibers was increased from 1.8 ± 0.2 cm to 2.1 ± 0.3 cm and 2.9 ± 0.4 cm against E. coli by increasing the amounts of C-dots from 2.9 mg and 5 mg. Also, the same behavior was observed against S. aureus where the inhibition zone is increased from 2.5 ± 0.1 cm to 3.2 and 3.5 cm by doubling the C-dots amounts in CS/PVA fiber. Moreover, bare and C-dots containing CS/PVA fibers were found blood compatible (nonhemolytic) up to 1 mg/mL concentration according to hemolysis and blood clotting tests.