Antifungal Activities of Chitosan and Nanoparticle Derivatives under Various pH Conditions (original) (raw)
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Antifungal Activity of Chitosan Nanoparticles and Correlation with Their Physical Properties
International Journal of Biomaterials, 2012
The need of natural antimicrobials is paramount to avoid harmful synthetic chemicals. The study aimed to determine the antifungal activity of natural compound chitosan and its nanoparticles forms againstCandida albicans, Fusarium solani and Aspergillus niger. Chitosan nanoparticles were prepared from low (LMW), high molecular weight (HMW) chitosan and its derivative, trimethyl chitosan (TMC). Particle size was increased when chitosan/TMC concentration was increased from 1 to 3 mg/mL. Their zeta potential ranged from +22 to +55 mV. Chitosan nanoparticles prepared from different concentrations of LMW and HMW were also found to serve a better inhibitory activity againstC.albicans(MICLMW=0.25–0.86 mg/mL andMICHMW=0.6–1.0 mg/mL) andF. solani(MICLMW=0.86–1.2 mg/mL andMICHMW=0.5–1.2 mg/mL) compared to the solution form (MIC=3 mg/mL for both MWs and species). This inhibitory effect was also influenced by particle size and zeta potential of chitosan nanoparticles. Besides,Aspergillus nigerwa...
Synthesis and anti-fungal effect of silver nanoparticles-chitosan composite particles
International journal of nanomedicine, 2015
Silver nanoparticles have been used in various fields, and several synthesis processes have been developed. The stability and dispersion of the synthesized nanoparticles is vital. The present article describes a novel approach for one-step synthesis of silver nanoparticles-embedded chitosan particles. The proposed approach was applied to simultaneously obtain and stabilize silver nanoparticles in a chitosan polymer matrix in-situ. The diameter of the synthesized chitosan composite particles ranged from 1.7 mm to 2.5 mm, and the embedded silver nanoparticles were measured to be 15±3.3 nm. Further, the analyses of ultraviolet-visible spectroscopy, energy dispersive spectroscopy, and X-ray diffraction were employed to characterize the prepared composites. The results show that the silver nanoparticles were distributed over the surface and interior of the chitosan spheres. The fabricated spheres had macroporous property, and could be used for many applications such as fungicidal agents ...
International journal of biological macromolecules, 2017
Though the metal nanoparticles (NPs) have been shown favorable results against fungal diseases, erratic environmental toxicity of NPs have raised serious concerns against their applications. Hence, it is vital to modify antifungal compounds into safe substitutes over synthetic chemicals. In this study, antifungal effects of chitosan nanoparticles (CNPs) and chitosan silver nanocomposites (CAgNCs) were compared against Fusarium oxysporum species complex. CNPs and CAgNCs were synthesized, characterized and compared based on the transmission electron microscope, X-ray diffraction, UV-vis absorbance spectra, particle size distribution, zeta potential and thermal stability analysis. Ultra-structural analysis on mycelium membrane of treated F. oxysporum showed that CNPs and CAgNCs could induce a pronounced membrane damage and disruption of the mycelium surface, increase the membrane permeability, and even cell disintegration. CAgNCs showed a significantly higher radial growth inhibition t...
Antibiotics
Nanotechnology is emerging as a new technology with encouraging innovations. Global antibiotic use has grown enormously, with antibiotic resistance increasing by about 80 percent. In view of this alarming situation, intensive research has been carried out into biogenic nanoparticles and their antibacterial, antifungal, and antitumor activities. Many methods are available to enhance stability and dispersion via peroration of conjugate with a polymer, such as chitosan, and other bioactive natural products. Two marine fungi were isolated and identified as Aspergillus sp. and Alternaria sp. via sequencing of the 16S rRNA gene. In this work, these strains were used to form the conjugation of biogenic silver nanoparticles (AgNPs) from Aspergillus sp. Silv2 extract and gold nanoparticles (AuNPs) from Alternaria sp. Gol2 extracts with chitosan to prepare chitosan–AgNPs and chitosan–AuNP conjugates. A variety of imaging and analytical methods, such as UV–vis, X-ray powder diffraction (XRD), ...
Antifungal Activity of Chitosan Nanoparticles and
2012
The need of natural antimicrobials is paramount to avoid harmful synthetic chemicals. The study aimed to determine the antifungal activity of natural compound chitosan and its nanoparticles forms against Candida albicans, Fusarium solani and Aspergillus niger. Chitosan nanoparticles were prepared from low (LMW), high molecular weight (HMW) chitosan and its derivative, trimethyl chitosan (TMC). Particle size was increased when chitosan/TMC concentration was increased from 1 to 3 mg/mL. Their zeta potential ranged from +22 to +55 mV. Chitosan nanoparticles prepared from different concentrations of LMW and HMW were also found to serve a better inhibitory activity against C. albicans (MICLMW = 0.25–0.86 mg/mL and MICHMW = 0.6–1.0 mg/mL) and F. solani (MICLMW = 0.86–1.2 mg/mL and MICHMW = 0.5–1.2 mg/mL) compared to the solution form (MIC = 3 mg/mL for both MWs and species). This inhibitory effect was also influenced by particle size and zeta potential of chitosan nanoparticles. Besides, Aspergillus niger was found to be resistant to chitosan nanoparticles except for nanoparticles prepared from higher concentrations of HMW. Antifungal activity of nanoparticles prepared from TMC was negligible. The parent compound therefore could be formulated and applied as a natural antifungal agent into nanoparticles form to enhance its antifungal activity.
Synthesis and Antimicrobial Activity of Silver N-Methyl Chitosan
Molekul
This study synthesized silver N-methyl chitosan (Ag-NMC) and tested it for its antimicrobial and antifungal activity. Ag-NMC was characterized by FTIR, XRD, measured for its molecular weight (MW), solubility, and toxicity. The antimicrobial activity was tested by the agar diffusion method, determining the MIC (Minimum Inhibitory Concentration), MBC (Minimum Bactericidal Concentration) against Staphylococcus aureus and Escherichia coli bacteria, and determining the Minimum Fungicidal Concentration (MFC) against the fungus Candida albicans. The results showed that Ag-NMC had MW, solubility, and LC50 of 555.65 g/mol, 50 mg/mL, 945,492 mg/L, respectively. The diameter of the inhibition zone from the resulting diffusion test showed that Ag-NMC had better antimicrobial activity than N-methyl chitosan (NMC) and chitosan. The MIC, MBC, and MFC values of Ag-NMC were always lower than that of NMC and chitosan.
Synthesis of Antimicrobial Chitosan-Silver Nanoparticles Mediated by Reusable Chitosan Fungal Beads
International Journal of Molecular Sciences
Nanoparticles, especially silver nanoparticles (Ag NPs), have gained significant attention in recent years as potential alternatives to traditional antibiotics for treating infectious diseases due to their ability to inhibit the growth of microorganisms effectively. Ag NPs can be synthesized using fungi extract, but the method is not practical for large-scale production due to time and biomass limitations. In this study, we explore the use of chitosan to encapsulate the mycelia of the white-rot fungus Stereum hirsutum and form chitosan fungal beads for use in multiple extractions and nanoparticle synthesis. The resulting nanoparticles were characterized using various techniques, including UV-vis spectrophotometry, transmission electron microscopy, dynamic light scattering, and X-ray diffraction analysis. The analysis revealed that the synthesized nanoparticles were composed of chitosan-silver nanoparticles (CS-Ag NPs) with a size of 25 nm. The chitosan fungal beads were reused in th...
This research is reports the fungicidal properties of nano-size silver/chitosan nanoformulations (NFs) used as an agent for antifungal treatment of various seed borne plant pathogens. Fungal phytopathogens, especially seed borne disease causing species, Rhizoctonia solani, Aspergillus flavus, Alternaria alterneta were isolated form chickpea seeds. Differences were observed in the antifungal activity of the silver nanoparticle, chitosan nanoparticles and silver /chitosan nanocomposite, upon the mycelial growth and zone of inhibition of the fungi. Extent of fungal inhibition was derived using the above information, in order to evaluate the antifungal efficacy of these nanoformulations against pathogens. Tests for the fungal growth revealed that the NFs showed significant inhibition effectiveness. This study suggests the possibility to use silver/chitosan NFs as an alternative to fungicides for controlling seed borne phytopathogens.
2021
This work was designed to study the incidence of Aspergillus fumigatus (A. fumigatus) in Ras cheese sold in different markets at Sohag city, Egypt and also in sputum samples of respiratory diseases patients admitted to Sohag University Hospital, as well as study the effect of silver (SNPs) and chitosan (CNPs) nanoparticles against the A. fumigatus isolates. Potato dextrose agar (PDA) was used for mycological culture of samples and the antifungal effect of nanoparticles (with different concentrations) using well diffusion method. High resolution transmission electron microscope (HRTEM) was used for detection of nanoparticles size, and scanning electron microscope (SEM) was used for investigation of nanoparticles effect on A.fumigatus morphology. The isolation rate of A. fumigatus was 22.11 % (21/95), 32.17 % (37/115) from Ras cheese and sputum samples, respectively. SNPs had inhibitory effect at concentrations 1 and 2 μg/ml, and complete growth inhibition with concentrations 4, 8, an...
Journal of Chemistry
Schiff-bases of chitosan (CS) and carboxymethyl chitosan (CMCS)/silver nanoparticles (AgNPs) have been synthesized, characterized, and evaluated as antimicrobial agents against two Gram +ve bacteria (Bacillus cereus and Staphylococcus aureus) and two Gram −ve bacteria (Escherichia coli and Pseudomonas aeruginosa) in addition to Candida albicans as a fungus. The in situ reactions of CS and/or CMCS with some pyrazole aldehyde derivatives in acidic media containing silver nitrate to yield silver nanoparticles loaded onto CS and CMCS/Schiff-bases were carried out. Characterizations of the prepared compounds via FTIR spectroscopy, SEM, TEM, and TGA were carried out. Schiff-bases/silver nanoparticles of CS and CMCS showed higher antimicrobial activity than the blank CS and CMCS. The presence of AgNO3 (3% wt%) displayed high antibacterial efficiencies with inhibition zones in the extent of 19–39 mm. TEM analysis showed that the size of the silver nanoparticles is in the range of 4–28 nm fo...