scholarly journals Biogenic Gold Nanoparticles as Potent Antibacterial and Antibiofilm Nano-Antibiotics against Pseudomonas aeruginosa

Antibiotics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 100 ◽  
Author(s):  
Syed Ghazanfar Ali ◽  
Mohammad Azam Ansari ◽  
Mohammad A. Alzohairy ◽  
Mohammad N. Alomary ◽  
Sami AlYahya ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Pseudomonas Aeruginosa ◽  
Gold Nanoparticles ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Tinospora Cordifolia ◽  
Confocal Laser ◽  
X Ray Diffraction ◽  
X Ray ◽  
Average Size

Abstract: Plant-based synthesis of eco-friendly nanoparticles has widespread applications in many fields, including medicine. Biofilm—a shield for pathogenic microorganisms—once formed, is difficult to destroy with antibiotics, making the pathogen resistant. Here, we synthesized gold nanoparticles (AuNPs) using the stem of an Ayurvedic medicinal plant, Tinospora cordifolia, and studied the action of AuNPs against Pseudomonas aeruginosa PAO1 biofilm. The synthesized AuNPs were characterized by techniques such as ultraviolet-visible spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, energy-dispersive X-ray diffraction, X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy. The AuNPs were spherically shaped with an average size of 16.1 nm. Further, the subminimum inhibitory concentrations (MICs) of AuNPs (50, 100, and 150 µg/mL) greatly affected the biofilm-forming ability of P. aeruginosa, as observed by crystal violet assay and SEM, which showed a decrease in the number of biofilm-forming cells with increasing AuNP concentration. This was further justified by confocal laser scanning microscopy (CLSM), which showed irregularities in the structure of the biofilm at the sub-MIC of AuNPs. Further, the interaction of AuNPs with PAO1 at the highest sub-MIC (150 µg/mL) showed the internalization of the nanoparticles, probably affecting the tendency of PAO1 to colonize on the surface of the nanoparticles. This study suggests that green-synthesized AuNPs can be used as effective nano-antibiotics against biofilm-related infections caused by P. aeruginosa.

scholarly journals Investigation of Spin Coating Cerium-Doped Hydroxyapatite Thin Films with Antifungal Properties

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 464
Author(s):  
Simona Liliana Iconaru ◽  
Mihai Valentin Predoi ◽  
Patrick Chapon ◽  
Sofia Gaiaschi ◽  
Krzysztof Rokosz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Spin Coating ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
X Ray ◽  
Antifungal Properties ◽  
Scanning Electron

In this study, the cerium-doped hydroxyapatite (Ca10−xCex(PO4)6(OH)2 with xCe = 0.1, 10Ce-HAp) coatings obtained by the spin coating method were presented for the first time. The stability of the 10Ce-HAp suspension particles used in the preparation of coatings was evaluated by ultrasonic studies, transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The surface morphology of the 10Ce-HAp coating was studied by SEM and atomic force microscopy (AFM) techniques. The obtained 10Ce-HAp coatings were uniform and without cracks or unevenness. Glow discharge optical emission spectroscopy (GDOES) and X-ray photoelectron spectroscopy (XPS) were used for the investigation of fine chemical depth profiling. The antifungal properties of the HAp and 10Ce-HAp suspensions and coatings were assessed using Candida albicans ATCC 10231 (C. albicans) fungal strain. The quantitative antifungal assays demonstrated that both 10Ce-HAp suspensions and coatings exhibited strong antifungal properties and that they successfully inhibited the development and adherence of C. albicans fungal cells for all the tested time intervals. The scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) visualization of the C. albicans fungal cells adherence to the 10Ce-HAp surface also demonstrated their strong inhibitory effects. In addition, the qualitative assays also suggested that the 10Ce-HAp coatings successfully stopped the biofilm formation.

scholarly journals Synthesis of Gold Nanoparticles Using Mimosa tenuiflora Extract, Assessments of Cytotoxicity, Cellular Uptake, and Catalysis

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Ericka Rodríguez-León ◽  
Blanca E. Rodríguez-Vázquez ◽  
Aarón Martínez-Higuera ◽  
César Rodríguez-Beas ◽  
Eduardo Larios-Rodríguez ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Laser Scanning ◽  
Nuclear Periphery ◽  
Laser Scanning Microscopy ◽  
Tree Bark ◽  
Bark Extract ◽  
Confocal Laser ◽  
Dependent Manner ◽  
X Ray ◽  
Mimosa Tenuiflora

Abstract Synthesis of gold nanoparticles (AuNPs) with plant extracts has gained great interest in the field of biomedicine due to its wide variety of health applications. In the present work, AuNPs were synthesized with Mimosa tenuiflora (Mt) bark extract at different metallic precursor concentrations. Mt extract was obtained by mixing the tree bark in ethanol-water. The antioxidant capacity of extract was evaluated using 2,2-diphenyl-1-picrylhydrazyl and total polyphenol assay. AuNPs were characterized by transmission electron microscopy, X-ray diffraction, UV-Vis and Fourier transform infrared spectroscopy, and X-ray photoelectron spectrometry for functional group determination onto their surface. AuMt (colloids formed by AuNPs and molecules of Mt) exhibit multiple shapes with sizes between 20 and 200 nm. AuMt were tested on methylene blue degradation in homogeneous catalysis adding sodium borohydride. The smallest NPs (AuMt1) have a degradation coefficient of 0.008/s and reach 50% degradation in 190s. Cell viability and cytotoxicity were evaluated in human umbilical vein endothelial cells (HUVEC), and a moderate cytotoxic effect at 24 and 48 h was found. However, toxicity does not behave in a dose-dependent manner. Cellular internalization of AuMt on HUVEC cells was analyzed by confocal laser scanning microscopy. For AuMt1, it can be observed that the material is dispersed into the cytoplasm, while in AuMt2, the material is concentrated in the nuclear periphery.

scholarly journals Synthesis of gold nanoparticles using Platycodon grandiflorum extract and its antipathogenic activity under optimal conditions

2020 ◽  
Vol 10 ◽  
pp. 184798042096169
Author(s):  
Periasamy Anbu ◽  
Subash CB Gopinath ◽  
S Jayanthi
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Plant Extracts ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Platycodon Grandiflorum ◽  
Transmission Electron ◽  
Flower Plant ◽  
Average Size

Gold nanoparticles have many applications in the biomedical field, mainly for drug delivery, cancer therapy, and detection of pathogenic microorganisms. In this study, gold nanoparticles synthesized using Platycodon grandiflorum (Balloon flower plant) extracts were evaluated for their antibacterial potential. Gold nanoparticles were synthesized at 20–50°C using different volumes of the leaf extract. Biosynthesis of gold nanoparticles was confirmed by ultraviolet–visible spectral absorption at 545 nm by surface plasmon resonance. The morphology and size of the P. grandiflorum gold nanoparticles were further characterized as spherical in shape with an average size of 15 nm in diameter by scanning electron microscopy and transmission electron microscopy. Energy-dispersive X-ray analysis clearly displayed the presence of gold particles. The structural analysis results with face central cubic crystalline nature and elemental composition, including gold, were confirmed by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. In addition, Fourier transform infrared results identified the functional group in P. grandiflorum that is involved in the reduction of metal ions to gold nanoparticles. The synthesized P. grandiflorum gold nanoparticles exhibited efficient antibacterial activity against Escherichia coli (16 mm) and Bacillus subtilis (11 mm). This report confirms the synthesis of gold nanoparticle from balloon flower plant extracts, which can be used as a reducing and stabilizing agent and demonstrates its antibacterial applications.

Investigation of HgBr x I 2-x using confocal laser scanning microscopy and x-ray diffraction

1998 ◽  
Author(s):  
George A. Stanciu ◽  
J. L. Oud ◽  
E. K. Polychronyadis ◽  
Maria Daviti ◽  
Angelia Stanciu ◽  
...  
Keyword(s):  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Effect of Cast Defects on the Corrosion Behavior and Mechanism of UNS C95810 Alloy in Artificial Seawater

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1790 ◽  
Author(s):  
Xu Zhao ◽  
Yuhong Qi ◽  
Jintao Wang ◽  
Zhanping Zhang ◽  
Jing Zhu ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Laser Scanning ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrochemical Testing ◽  
Alloy Microstructure

To study the effect of cast defects on the corrosion behavior and mechanism of the UNS C95810 alloy in seawater, an investigation was conducted by weight loss determination, scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), X-ray diffraction (XRD) and electrochemical testing of the specimen with and without cast defects on the surface. The results show that the corrosion rate of the alloy with cast defects is higher than that of the alloy without cast defects, but the defects do not change the composition of the resulting corrosion products. The defects increase the complexity of the alloy microstructure and the tendency toward galvanic corrosion, which reduce the corrosion potential from −3.83 to −86.31 mV and increase the corrosion current density from 0.228 to 0.23 μA⋅cm−2.

scholarly journals Pseudomonas aeruginosa Psl Is a Galactose- and Mannose-Rich Exopolysaccharide

2007 ◽  
Vol 189 (22) ◽  
pp. 8353-8356 ◽  
Author(s):  
Luyan Ma ◽  
Haiping Lu ◽  
April Sprinkle ◽  
Matthew R. Parsek ◽  
Daniel J. Wozniak
Keyword(s):  
Electron Microscopy ◽  
Pseudomonas Aeruginosa ◽  
Chemical Composition ◽  
Confocal Laser Scanning Microscopy ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Lectin Staining ◽  
Polysaccharide Synthesis

ABSTRACT The Pseudomonas aeruginosa polysaccharide synthesis locus (psl) is predicted to encode an exopolysaccharide which is critical for biofilm formation. Here we used chemical composition analyses and mannose- or galactose-specific lectin staining, followed by confocal laser scanning microscopy and electron microscopy, to show that Psl is a galactose-rich and mannose-rich exopolysaccharide.

Application of levitation melting to the separation of oxide inclusions from nitrides and carbides in Ni-based superalloy

2020 ◽  
Vol 117 (2) ◽  
pp. 206
Author(s):  
Xiaoyong Gao ◽  
Lin Zhang ◽  
Xuanhui Qu ◽  
Yifeng Luan ◽  
Xiaowei Chen
Keyword(s):  
Laser Scanning ◽  
Separation Efficiency ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Separation Mechanism ◽  
X Ray Diffraction ◽  
Levitation Melting ◽  
X Ray ◽  
Automated Scanning

Oxides are usually surrounded by nitrides and carbides in superalloys, which contain high Ti and Nb contents. This makes it difficult to precisely characterize oxide size and composition. Separation of oxides from nitrides and carbides in FGH96 superalloy was carried out by levitation melting to accurately characterize oxides. Manual and automated scanning electron microscopy and energy-dispersive X-ray spectroscopy observations as well as X-ray diffraction were used to characterize inclusions. In the billet, nearly all oxides were surrounded by nitrides and carbides. After levitation melting, however, the majority of oxides were separated, agglomerated and floated to the top surface. The separation efficiency of oxides from nitrides is approximately 85.5%. Oxides were determined as MgO-Al2O3 spinel with the size of 1∼10 µm. Finally, in situ confocal laser scanning microscopy clarified the separation mechanism.

Confocal and SEM imaging to demonstrate food pathogen- biofilm biocontrol by pyocyanin from Pseudomonas aeruginosa BTRY1

2016 ◽  
Vol 6 (01) ◽  
pp. 5218
Author(s):  
Laxmi Mohandas ◽  
Anju T. R. ◽  
Sarita G. Bhat*
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Antibiofilm Activity ◽  
Opportunistic Pathogens ◽  
Redox Active ◽  
Sem Imaging ◽  
The Impact

An assortment of redox-active phenazine compounds like pyocyanin with their characteristic blue-green colour are synthesized by Pseudomonas aeruginosa, Gram-negative opportunistic pathogens, which are also considered one of the most commercially valuable microorganisms. In this study, pyocyanin from Pseudomonas aeruginosa BTRY1 from food sample was assessed for its antibiofilm activity by micro titer plate assay against strong biofilm producers belonging to the genera Bacillus, Staphylococcus, Brevibacterium and Micrococcus. Pyocyanin inhibited biofilm activity in very minute concentrations. This was also confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Both SEM and CLSM helped to visualize the biocontrol of biofilm formation by eight pathogens. The imaging and quantification by CLSM also established the impact of pyocyanin on biofilm-biocontrol mainly in the food industry.

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