Chitosan/silver nanocomposites: Synergistic antibacterial action of silver nanoparticles and silver ions (original) (raw)
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2018
A simple and eco-friendly approach has been successfully developed for the preparation of chitosan nanocomposites films loaded with silver nanoparticles using kumquat extract as a biological reducing agent. The chitosan/silver nanocomposites (CTS/Ag NCPs) films were prepared from chitosan/silver nanocomposites solution and dried for 14 h at 70C in a vacuum oven with the pressure of 0.03 Mpa. The morphology and characterization of CTS/Ag NCPs films have been also determined by FTIR, XRD, and SEM. The UV-vis spectroscopy and TEM image indicated that synthesized chitosan/silver nanocomposites have spherical shape with their uniform dispersion and their average particle size of about 20-30 nm. The prepared CTS/Ag NCPs films showed their great antibacterial activity on Staphylococcus aureus (S. Aureus) and Escherichia coli (E. coli). Therefore, this eco-friendly method that would be used for the preparation of chitosan/Ag nanocomposites films could be competitive and alternative to the e...
Advances in Materials Science and Engineering, 2013
The aim of this study is to investigate the antibacterial properties and characterization of chitosan-silver nanoparticle composite materials. Chitosan-silver nanoparticle composite material was synthesized by adding AgNO3and NaOH solutions to chitosan solution at 95°C. Different concentrations (0,02 M, 0,04 M, and 0,06 M) of AgNO3were used for synthesis. Chitosan-silver nanoparticle composite materials were characterized by Transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet (UV) spectrophotometer, and Fourier transform infrared (FTIR) spectrometer techniques.Escherichia coli,Acinetobacter baumannii,Staphylococcus aureus,Enterococcus faecalis,Pseudomonas aeruginosa, andStreptococcus pneumoniaewere used to test the bactericidal efficiency of synthesized chitosan-Ag nanoparticle composite materials. The biological activity was determined by the minimum bacterial concentration (MBC) of the materials. Antibacterial effect of chitosan-silver nanoparticle materia...
Factors Affecting the Antibacterial Activity of Chitosan-Silver Nanocomposite
IET Nanobiotechnology, 2017
This study provides the optimum preparation parameters of chitosan-silver nanoparticles composite (CSNC) with promising antibacterial activity against the most common bacterial infections found on burn wounds. CSNC was synthesised by simple green chemical reduction method with different preparation factors. Chitosan was used to reduce silver nitrate and stabilise silver nanoparticles in the medium. For this reason, spectroscopic and microscopic techniques as, ultraviolet-visible Fourier transform infrared spectroscopy and transmission electron microscopy were used in the study of the molecular and morphological properties of the resultant composites. Furthermore, the composite was assessed in terms of Ag-ions release by AAS and its efficacy as antibacterial material. As a result, CSNC showed stronger antibacterial effect than its individual components (chitosan and silver nitrate solutions) towards Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria. CSNC prepared in this study showed highest inhibition percentage of bacterial growth up to 96% at concentration of 220 μg/ml.
Synergistic antibacterial activity of chitosan–silver nanocomposites on Staphylococcus aureus
Nanotechnology, 2011
The approach of combining different mechanisms of antibacterial action by designing hybrid nanomaterials provides a new paradigm in the fight against resistant bacteria. Here, we present a new method for the synthesis of silver nanoparticles enveloped in the biopolymer chitosan. The method aims at the production of bionanocomposites with enhanced antibacterial properties. We find that chitosan and silver nanoparticles act synergistically against two strains of Gram-positive Staphylococcus aureus (S. aureus). As a result the bionanocomposites exhibit higher antibacterial activity than any component acting alone. The minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations of the chitosan-silver nanoparticles synthesized at 0 • C were found to be lower than those reported for other types of silver nanoparticles. Atomic force microscopy (AFM) revealed dramatic changes in morphology of S. aureus cells due to disruption of bacterial cell wall integrity after incubation with chitosan-silver nanoparticles. Finally, we demonstrate that silver nanoparticles can be used not only as antibacterial agents but also as excellent plasmonic substrates to identify bacteria and monitor the induced biochemical changes in the bacterial cell wall via surface enhanced Raman scattering (SERS) spectroscopy.
Synthesis of Chitosan-silver nanocomposites and their antibacterial activity
International Journal of Scientific and Engineering Research
The present study explores the in situ fabrication of chitosan-silver nanocomposites in view of their increasing applications as antimicrobial packaging, wound dressing and antibacterial materials. Chitosan/Silver nanocomposites were prepared by embedding of silver nanoparticles in chitosan polymer. Synthesis of nanocomposites was confirmed by Fourier Transform Infrared (FTIR) spectroscopy, X-Ray Diffraction (XRD) analysis and Differential Scanning Calorimetry (DSC) etc. In addition, the formed nanocomposites have an average particle size of ~10-15 nm as observed by Transmission Electron Microscopy (TEM). Their antibacterial activity was assessed by zone of inhibition method against Staphylococcus aureus MTCC 1809, Pseudomonas aeruginosa MTCC 424 and Salmonella entrica MTCC 1253 in vitro.
Colloids and Surfaces B-biointerfaces, 2010
The present investigation involves the synthesis of porous chitosan-silver nanocomposite films in view of their increasing areas of application in wound dressing, antibacterial application, and water purification. The entire process consists of three-steps including silver ion-poly(ethylene glycol) matrix preparation, addition of chitosan matrix, and removal of poly(ethylene glycol) from the film matrix. Uniform porous and brown colour chitosan films impregnated with silver nanoparticles (AgNPs) were successfully fabricated by this facile approach. Both, poly(ethylene glycol) (PEG) and chitosan (CS) played vital roles in the reduction of metal ions into nanoparticles (NPs) as well as provided good stability to the formed nanoparticles. The developed porous chitosan-silver nanocomposite (PCSSNC) films were characterized by UV-vis and FTIR spectroscopy, and thermogravimetric analysis for the confirmation of nanoparticles formation. The morphology of silver nanoparticles in nanocomposite films was tested by optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The embedded AgNPs were clearly observed throughout the film in SEM and the extracted AgNPs from the porous chitosan-silver nanocomposite showed ∼12 nm in TEM. Improved mechanical properties were observed for porous chitosan-silver nanocomposite than for chitosan blend (CSB) and chitosan-silver nanocomposite (CSSNC) films. Further, the examined antibacterial activity results of these films revealed that porous chitosan-silver nanocomposite films exhibited superior inhibition.
Due to their antibacterial activity and biocompatibility, chitosan and chitosan derivatives have ability of participating in biological applications. The prepared Cs g-PAN/Ag nanocomposites are reported as antibacterial agents that exhibit efficient antibacterial activity in vitro. The prepared chitosan-g- PAN/Ag nanocomposite was provided by FTIR and gravimetric methods. UV spectra and TEM images show silver nanoparticles with average 15 20 nm dispersed homogeneously in (CS-g-PAN/Ag) nanocomposite. The antimicrobial activity examined against gram negative bacterium (E. coli) and gram positive bacterium (Staphylococcus aureus) in addition to yeast (Candida albicans) and fungi (Aspergillusniger) is evaluated in vitro. The MIC for E. coli for in vivo application was also examined. In vivo antibacterial activity against E. coli has been evaluated by using an intestine-infected rat model. Experimental results indicated that the number of bacteria surviving in the small intestine is lower than in the untreated group. These nanocomposite open up a new avenue for design and synthesis of next-generation antibacterial agents as alternatives to antibiotics.
The antibacterial properties of a novel chitosan–Ag-nanoparticle composite
International journal of …, 2008
Escherichia coli expressing recombinant green fluorescent protein was used to test the bactericidal efficacy of a newly synthesized chitosan-Ag-nanoparticle composite. The composite was found to have significantly higher antimicrobial activity than its components at their respective concentrations. The one-pot synthesis method led to the formation of small Ag nanoparticles attached to the polymer which can be dispersed in media of pH ≤ 6.3. The presence of a small percentage (2.15%, w/w) of metal nanoparticles in the composite was enough to significantly enhance inactivation of E. coli as compared with unaltered chitosan. Fluorescence spectroscopy indicated that bacterial growth stopped immediately after exposure of E. coli to the composite, with release of cellular green fluorescent protein into the medium at a faster rate than with chitosan. Fluorescence confocal laser scanning and scanning electron microscopy showed attachment of the bacteria to the composite and their subsequent fragmentation. Native protein gel electrophoresis experiments indicated no effect of the composite on bacterial proteins.
Silver-N-Carboxymethyl Chitosan Nanocomposites: Synthesis and its Antibacterial Activities
Journal of Bioterrorism & Biodefense, 2010
In this work, silver-N-carboxymethyl chitosan nanocomposites (Ag-N-CMC) were synthesized in the homogeneous state via the reduction of Ag + (using [Ag(NH 3) 2 ]OH instead of AgNO 3) by NaBH 4 in the presence of water-soluble N-carboxymethyl chitosan as a stabilizer. The resulting Ag-N-CMG was characterized by FTIR, TEM and UV-vis spectra. The results showed that the average particle size of silver nanoparticles was little affected by the concentration of Ag + added and was between 2 and 10nm. The characteristic surface plasmon resonance band of silver nanoparticles centered at about 398-410nm. In vitro antibacterial activities of Ag-N-CMC nanocomposites were evaluated against both gram-negative bacteria: Escherichia coli ATCC 25922 (Ec) and Pseudomonas aeruginosa VM201 (Pseu) and gram-positive bacteria: Staphylococcus aureus ATCC 1128 (Sta) and Bacillus cereus ATCC 9946 (Bc). The results shown that the Ag-N-CMC nanocomposites could inhibit the growth and multiplication of the tested bacteria.
2014
Multifunctional bionanocomposites have been prepared by loading chitosan matrix with silvermontmorillonite antimicrobial nanoparticles obtained by replacing Na + ions of natural montmorillonite with silver ions. This filler has been chosen for its twofold advantage to serve as silver supporting material and to confer new and better performance to the obtained material. It has been proved that the achievement of the intercalation of chitosan into the silicate galleries of montomorillonite as well as the interaction between chitosan and Ag ions and silver particles lead to an enhancement of the thermal stability, to an improvement of mechanical strengths and to a reduction of the liquid water uptake of the obtained bionanocomposites. Results also show that silver ions are released in a steady and prolonged manner providing, after 24 h, a significant reduction in the microbial growth of Pseudomonas spp.