scholarly journals Microwave-Assisted Synthesis of Chitosan/Polyvinyl Alcohol Silver Nanoparticles Gel for Wound Dressing Applications

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Nguyen Thi Hiep ◽  
Huynh Chan Khon ◽  
Vo Van Thanh Niem ◽  
Vo Van Toi ◽  
Tran Ngoc Quyen ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Microwave Irradiation ◽  
Polyvinyl Alcohol ◽  
Silver Ions ◽  
Diffusion Method ◽  
Poly Vinyl Alcohol ◽  
Microwave Assisted Synthesis ◽  
Vis Spectroscopy

The purpose of this study was to fabricate chitosan/poly(vinyl alcohol)/Ag nanoparticles (CPA) gels with microwave-assistance for skin applications. Microwave irradiation was employed to reduce silver ions to silver nanoparticles and to crosslink chitosan (CS) with polyvinyl alcohol (PVA). The presence of silver nanoparticles in CPA gels matrix was examined using UV-Vis spectroscopy, transmission electron microscopy, and X-ray diffraction. The interaction of CS and PVA was analysed by Fourier transform infrared spectroscopy. The release of silver ions was determined by atomic absorption spectrometry. The antimicrobial properties of CPA gels againstP. aeruginosaandS. aureuswere investigated using agar diffusion method. Finally, the biocompatibility and wound-healing ability of the gels were studied using fibroblast cells (in vitro) and mice models (in vivo). In conclusion, the results showed that CPA gels were successfully fabricated using microwave irradiation method. These gels can be applied to heal an open wound thanks to their antibacterial activity and biocompatibility.

Silver nanoparticles used to counter Monilinia fructicola fungicide-resistance and reduce fungicide environmental footprint 

2021 ◽  
Author(s):  
Constantinos Chrysikopoulos ◽  
Anastasios A. Malandrakis ◽  
Nektarios Kavroulakis ◽  
Anthi Stefanarou
Keyword(s):  
Silver Nanoparticles ◽  
Control Plant ◽  
Resistance Mutation ◽  
Silver Ions ◽  
Apple Fruit ◽  
Ag Nps ◽  
Gene Target ◽  
Benzimidazole Fungicides

<div><span>The potential of silver nanoparticles (Ag-NPs) to control plant pathogen <em>Monilia</em><em>fructicola </em>and to deter environmental contamination by reducing fungicide doses was evaluated <em>in vitro </em>and <em>in vivo. </em> </span>F<span>ungitoxicity screening </span>of <em><span>M. fructicola </span></em><span>isolates resulted in the detection of 18 benzimidazole-resistant (BEN-R) isolates with reduced sensitivity to fungicides  thiophanate methyl (TM)  and carbendazim. All resistant isolates caried the E198A resistance mutation in their </span><em><span>β</span>-</em>tubulin gene, target site of the benzimidazole fungicides. <span>Ag-NPs could effectively control both sensitive (BEN-S) and resistant isolates while the combination of Ag-NPs with TM significantly enhanced their fungitoxic effect both <em>in vitro </em>and in apple fruit tests. The positive correlation observed between Ag-NPs and TM+Ag-NPs treatments indicates a mixture-enhanced Ag-NPs activity/availability as a possible mechanism of synergy. No correlation between Ag-NPs  and AgNO<sub>3 </sub>could  be found suggesting difference(s) in the fungitoxic mechanism of action between Nps and their bulk/ionic counterparts. Indications of the involvement of energy (ATP) metabolism in the mode of action of Ag-NPs were also evident by the synergy observed between Ag-NPs and the </span>oxidative phosphorylation<span>-uncoupler fluazinam (FM) against both BEN-R and BEN-S phenotypes. The role of silver ions release on the inhibitory action of Ag-NPs against the fungusis probably limited since the AgNPs/NaCl combination enhanced fungitoxicity, a fact that could not be justified by the expected binding of silver with chlorine ions. Concluding, Ag-NPs can be effectively used as a means of controlling both BEN-S and BEN-R <em>M. </em><em>fructicola </em>isolates </span>while <span>their combination with conventional fungicides should aid anti-resistant strategies and reduce the environmental impact of synthetic fungicides by reducing effective doses to the control the pathogen.</span></div>

scholarly journals In Vivo Study of the Antibacterial Chitosan/Polyvinyl Alcohol Loaded with Silver Nanoparticle Hydrogel for Wound Healing Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Tan Dat Nguyen ◽  
Thanh Truc Nguyen ◽  
Khanh Loan Ly ◽  
Anh Hien Tran ◽  
Thi Thanh Ngoc Nguyen ◽  
...  
Keyword(s):  
Wound Healing ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Polyvinyl Alcohol ◽  
Healing Rate ◽  
Antibacterial Effects ◽  
Topical Gel ◽  
Significant Difference

Silver nanoparticles have attracted great interests widely in medicine due to its great characteristics of antibacterial activity. In this research, the antibacterial activity and biocompatibility of a topical gel synthesized from polyvinyl alcohol, chitosan, and silver nanoparticles were studied. Hydrogels with different concentrations of silver nanoparticles (15 ppm, 30 ppm, and 60 ppm) were evaluated to compare their antibacterial activity, nanoparticles’ sizes, and in vivo behaviors. The resulted silver nanoparticles in the hydrogel were characterized by TEM showing the nanoparticles’ sizes less than 22 nm. The in vitro results prove that the antibacterial effects of all of the samples are satisfied. However, the in vivo results demonstrate the significant difference among different hydrogels in wound healing, where hydrogel with 30 ppm shows the best healing rate.

scholarly journals Green production of silver nanoparticles, evaluation of their nematicidal activity against Meloidogyne javanica and their impact on growth of faba bean

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Seham M. Hamed ◽  
Eman S. Hagag ◽  
Neveen Abd El-Raouf
Keyword(s):  
Silver Nanoparticles ◽  
Plant Growth ◽  
Faba Bean ◽  
Meloidogyne Javanica ◽  
Plant Diseases ◽  
Ag Nps ◽  
Vitro Assay ◽  
Vis Spectroscopy

Abstract Background Cyanobacterium-based silver nanoparticles are considered not only as an efficient nano-nematicide but also as a bio-stimulant material for plant growth. They could be employed as a part of an integrated program for controlling some plant diseases. Results In this study, silver nanoparticles (Ag-NPs) were biosynthesized from aqueous extract of the cyanobacterium, Nostoc sp. PCC7524. Full characterization of the biosynthesized Ag-NPs was monitored by UV-vis spectroscopy, transmission electron microscopy, X-ray diffraction pattern, Zeta sizer, and Fourier transform infrared spectroscopy. In vitro assay against the root-knot nematode Meloidogyne javanica showed that Ag-NPs significantly decreased egg hatching of M. javanica at different applied concentrations (3, 6, 12, 25, and 50%, v/v). Fifty percent of Ag-NPs induced the highest reduction percent (94.66%). Moreover, Ag-NPs and AgNO3 significantly increased the percentages of larval mortality of the second-stage juveniles (J2) with concentration and time-dependent responses. Ag-NPs or AgNO3 at 2.4 ml/l, 24 h, completely inhibited the growth of J2 compared to 23% inhibition using aqueous cyanobacterial extract (ACE). In vivo effect of Ag-NPs on faba bean-infected plant under greenhouse conditions was achieved by treating soil with three different concentrations of 1, 2, and 3 ml/kg soil over two consecutive seasons. Ag-NPs significantly reduced root galling from 39.6 to 78.7% and J2 population in the soils from 32.2% to 86.7% in the 2018 season and from 21.9 to 78.1% and 40.0 to 81.0% in the 2019 season, respectively. Moreover, 3 ml/kg soil of Ag-NP treatment showed statistically comparable effects to that of vydate nematicide but with remarkable enhancement of faba bean growth parameters as compared to those of vydate or AgNO3 treatments in the two seasons. Conclusions The considerable in vitro and in vivo nematicidal potential of the cyanobacterium-based Ag-NPs, besides their bio-stimulant effect on plant growth, makes them feasible for the biological control of M. javanica.

scholarly journals Assessment of Charged AuNPs: From Synthesis to Innate Immune Recognition

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
K. Rahme ◽  
G. Minassian ◽  
M. Sarkis ◽  
M. Nakhl ◽  
R. El Hage ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Human Blood ◽  
Size Variation ◽  
Poly Vinyl Alcohol ◽  
Human Blood Plasma ◽  
Immune Recognition ◽  
Adsorption Affinity ◽  
Vis Spectroscopy

Gold nanoparticle (AuNP) physicochemical characteristics, mainly size and charge, modulate their biodistribution, cytotoxicity, and immunorecognition as reported fromin vitroandin vivostudies. While data fromin vitrostudies could be biased by several factors including activation of cells upon isolation and lack of sera proteins in the microenvironment of primary generated cell lines,in vivostudies are costly and time-consuming and require ethics consideration. In this study, we developed a simple and novelin vivo-like method to test for NP immunorecognition from freshly withdrawn human blood samples. AuNPs with a size range of 30 ± 5 nm coated with cationic poly(L-lysine) (PLL) dendrigraft and slightly negative poly(vinyl alcohol) (PVA) were synthesized in water. PLL-capped AuNPs were further coated with poly(ethylene glycol) (PEG) to obtain nearly neutrally charged PEG-AuNPs. Physicochemical properties were determined using zeta potential measurements, UV-Vis spectroscopy, dynamic light scattering (DLS), and scanning electron microscopy (SEM). Gel electrophoretic separation, zeta potential, and DLS were also used to characterize our NPs after human blood plasma treatment. PLL-AuNPs showed similar variation in charge and binding affinity to plasma proteins in comparison with PVA-AuNPs. However, PLL-AuNPs.protein complexes revealed a drastic change in size compared to the other tested particles. Results obtained from the neutrophil function test and pyridine formazan extraction revealed the highest activation level of neutrophils (~70%) by 50 μg/mL of PLL-AuNPs compared to a null induction by PEG- and PVA-AuNPs. This observation was further verified by flow cytometry analysis of polymorphonuclear cell size variation in the presence of coated AuNPs. Overall, ourin vivo-like method, to test for NP immunorecognition, proved to be reliable and effective. Finally, our data supports the use of PEG-AuNPs as promising vehicles for drug delivery, as they exhibit minimal protein adsorption affinity and insignificant charge and size variation once introduced in whole blood.

scholarly journals Facile synthesis of silver nanoparticles using Averrhoa bilimbi L and Plum extracts and investigation on the synergistic bioactivity using in vitro models

2019 ◽  
Vol 8 (1) ◽  
pp. 873-884 ◽  
Author(s):  
Suresh Sagadevan ◽  
Selvaraj Vennila ◽  
Preeti Singh ◽  
Jayasingh Anita Lett ◽  
Mohd Rafie Johan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Salmonella Typhi ◽  
In Vitro Models ◽  
Diffusion Method ◽  
Gram Positive ◽  
Gram Negative ◽  
Vis Spectroscopy ◽  
Test Cultures

Abstract The bacterial communities (Gram-negative and Gram-positive) form the biofilms which oppose the mode of action of antibiotics and affecting the immune system of the human. These chronic infections related to biofilm are always hard to be cured because of their inherent resistance to both antimicrobial agents and host defense. The present study is devoted to the synthesis of silver nanoparticles (AgNPs) using aqueous extracts of Averrhoa bilimbi leaf and Plum fruit (Prunus bokharensis) and its inhibitory effect on Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Salmonella typhi. Here, AgNPs) were successfully prepared by green synthesis method obtained by the reduction of silver nitrate into silver ions. The synthesized AgNPs were characterized by UV-Vis Spectroscopy, XRD, FTIR, FESEM-EDAX and DLS analysis. The antimicrobial effects of the two extract were evaluated by the disk diffusion method. The green synthesized AgNPs exhibited good antibacterial activity against both Gram-negative and Gram-positive. They were also analyzed for their significant antibacterial activities against all the test cultures exposed whereas Escherichia coli and Salmonella typhi topped among other test cultures. The anti-proliferative activity of phytochemical mediated synthesis of Ag NPs was investigated for their cytotoxicity in Vero and Human epidermoid larynx carcinoma cell lines (HEp-2) based on their viability using MTT assay. The present study also represents the synergistic bioactivity of silver nanoparticles using in vitro models.

scholarly journals Antibacterial Effect of Silver Nanoparticles Synthesized Using Murraya koenigii (L.) against Multidrug-Resistant Pathogens

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Faizan Abul Qais ◽  
Anam Shafiq ◽  
Haris M. Khan ◽  
Fohad M. Husain ◽  
Rais A. Khan ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Bacterial Infections ◽  
Enteric Bacteria ◽  
Multidrug Resistant ◽  
Murraya Koenigii ◽  
E Coli ◽  
Vis Spectroscopy ◽  
Zones Of Inhibition

Development of multidrug resistance among pathogens has become a global problem for chemotherapy of bacterial infections. Extended-spectrum β-lactamase- (ESβL-) producing enteric bacteria and methicillin-resistant Staphylococcus aureus (MRSA) are the two major groups of problematic MDR bacteria that have evolved rapidly in the recent past. In this study, the aqueous extract of Murraya koenigii leaves was used for synthesis of silver nanoparticles. The synthesized MK-AgNPs were characterized using UV-vis spectroscopy, FTIR, XRD, SEM, and TEM, and their antibacterial potential was evaluated on multiple ESβL-producing enteric bacteria and MRSA. The nanoparticles were predominantly found to be spheroidal with particle size distribution in the range of 5–20 nm. There was 60.86% silver content in MK-AgNPs. Evaluation of antibacterial activity by the disc-diffusion assay revealed that MK-AgNPs effectively inhibited the growth of test pathogens with varying sized zones of inhibition. The MICs of MK-AgNPs against both MRSA and methicillin-sensitive S. aureus (MSSA) strains were 32 μg/ml, while for ESβL-producing E. coli, it ranged from 32 to 64 μg/ml. The control strain of E. coli (ECS) was relatively more sensitive with an MIC of 16 μg/ml. The MBCs were in accordance with the respective MICs. Analysis of growth kinetics revealed that the growth of all tested S. aureus strains was inhibited (∼90%) in presence of 32 μg/ml of MK-AgNPs. The sensitive strain of E. coli (ECS) showed least resistance to MK-AgNPs with >81% inhibition at 16 μg/ml. The present investigation revealed an encouraging result on in vitro efficacy of green synthesized MK-AgNPs and needed further in vivo assessment for its therapeutic efficacy against MDR bacteria.

scholarly journals Antifungal screening and molecular docking simulation of silica supported synthesized sitosteryl hydrogen phthalate using microwave irradiation

2020 ◽  
Vol 74 (6) ◽  
pp. 377-388
Author(s):  
Azhar Khan ◽  
Sunil Sharma ◽  
Abhishek Gehlot ◽  
Mona Gupta ◽  
Mahboob Alam
Keyword(s):  
Molecular Docking ◽  
Microwave Irradiation ◽  
High Resolution Mass Spectrometry ◽  
Reaction Times ◽  
Docking Simulation ◽  
Diffusion Method ◽  
Microwave Assisted Synthesis ◽  
Hydrogen Phthalate ◽  
Molecular Docking Simulation

In this study, steroidal sitosteryl hydrogen phthalate (stigmast-5-en-3b-yl hydrogen phthalate) was synthesized by the reaction of 3b-sitosterol and phthalic anhydride using silica gel as a solid support under microwave irradiation (MWI). The comparative study of microwave assisted synthesis and conventional synthesis of the steroidal compound in a hazardous solvent revealed that the former method provided shortened reaction times at increased yields. The compounds obtained by the two procedures were characterized by infrared spectroscopy, proton, carbon-13 nuclear magnetic resonance (1H and 13C NMR) and high-resolution mass spectrometry. The synthesized compound was screened for in vitro antifungal activity against Aspergillus niger and Candida albicans by the Kirby-Bauer Well Diffusion method. The synthesized compound was subjected to the molecular docking simulation with a receptor (CYP51). The findings of the antifungal and docking studies revealed that the synthesized sitosteryl hydrogen phthalate could be considered as a suitable inhibitor of Lanosterol 14a-demethylase (CYP51). In addition, the molecular docking approach was applied to design hypothetical derivatives of sitosteryl hydrogen phthalate inhibitors against the antifungal target and to compare findings with the binding score of the molecular synthesized 3b-sitosteryl hydrogen phthalate.

scholarly journals Silver Nanoparticles and Their Antibacterial Applications

2021 ◽  
Vol 22 (13) ◽  
pp. 7202
Author(s):  
Tamara Bruna ◽  
Francisca Maldonado-Bravo ◽  
Paul Jara ◽  
Nelson Caro
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Agents ◽  
Multidrug Resistant ◽  
Secondary Effects ◽  
Cytotoxic Effects ◽  
Factors Affecting ◽  
Gram Positive Bacteria ◽  
Resistant Strains

Silver nanoparticles (AgNPs) have been imposed as an excellent antimicrobial agent being able to combat bacteria in vitro and in vivo causing infections. The antibacterial capacity of AgNPs covers Gram-negative and Gram-positive bacteria, including multidrug resistant strains. AgNPs exhibit multiple and simultaneous mechanisms of action and in combination with antibacterial agents as organic compounds or antibiotics it has shown synergistic effect against pathogens bacteria such as Escherichia coli and Staphylococcus aureus. The characteristics of silver nanoparticles make them suitable for their application in medical and healthcare products where they may treat infections or prevent them efficiently. With the urgent need for new efficient antibacterial agents, this review aims to establish factors affecting antibacterial and cytotoxic effects of silver nanoparticles, as well as to expose the advantages of using AgNPs as new antibacterial agents in combination with antibiotic, which will reduce the dosage needed and prevent secondary effects associated to both.

scholarly journals Development of Cephradine-Loaded Gelatin/Polyvinyl Alcohol Electrospun Nanofibers for Effective Diabetic Wound Healing: In-Vitro and In-Vivo Assessments

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 349
Author(s):  
Anam Razzaq ◽  
Zaheer Ullah Khan ◽  
Aasim Saeed ◽  
Kiramat Ali Shah ◽  
Naveed Ullah Khan ◽  
...  
Keyword(s):  
Wound Healing ◽  
Polyvinyl Alcohol ◽  
Mtt Assay ◽  
Chronic Wound ◽  
Drug Loading ◽  
Group Identification ◽  
Wound Infections ◽  
Diabetic Wound

Diabetic wound infections caused by conventional antibiotic-resistant Staphylococcus aureus strains are fast emerging, leading to life-threatening situations (e.g., high costs, morbidity, and mortality) associated with delayed healing and chronic inflammation. Electrospinning is one of the most widely used techniques for the fabrication of nanofibers (NFs), induced by a high voltage applied to a drug-loaded polymer solution. Particular attention is given to electrospun NFs for pharmaceutical applications (e.g., original drug delivery systems) and tissue regeneration (e.g., as tissue scaffolds). However, there is a paucity of reports related to their application in diabetic wound infections. Therefore, we prepared eco-friendly, biodegradable, low-immunogenic, and biocompatible gelatin (GEL)/polyvinyl alcohol (PVA) electrospun NFs (BNFs), in which we loaded the broad-spectrum antibiotic cephradine (Ceph). The resulting drug-loaded NFs (LNFs) were characterized physically using ultraviolet-visible (UV-Vis) spectrophotometry (for drug loading capacity (LC), drug encapsulation efficiency (EE), and drug release kinetics determination), thermogravimetric analysis (TGA) (for thermostability evaluation), scanning electron microscopy (SEM) (for surface morphology analysis), and Fourier-transform infrared spectroscopy (FTIR) (for functional group identification). LNFs were further characterized biologically by in-vitro assessment of their potency against S. aureus clinical strains (N = 16) using the Kirby–Bauer test and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, by ex-vivo assessment to evaluate their cytotoxicity against primary human epidermal keratinocytes using MTT assay, and by in-vivo assessment to estimate their diabetic chronic wound-healing efficiency using NcZ10 diabetic/obese mice (N = 18). Thin and uniform NFs with a smooth surface and standard size (<400 nm) were observed by SEM at the optimized 5:5 (GEL:PVA) volumetric ratio. FTIR analyses confirmed the drug loading into BNFs. Compared to free Ceph, LNFs were significantly more thermostable and exhibited sustained/controlled Ceph release. LNFs also exerted a significantly stronger antibacterial activity both in-vitro and in-vivo. LNFs were significantly safer and more efficient for bacterial clearance-induced faster chronic wound healing. LNF-based therapy could be employed as a valuable dressing material to heal S. aureus-induced chronic wounds in diabetic subjects.

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