scholarly journals Bactericidal Activity of Usnic Acid-Chitosan Nanoparticles against Persister Cells of Biofilm-Forming Pathogenic Bacteria

Marine Drugs ◽  
2020 ◽  
Vol 18 (5) ◽  
pp. 270
Author(s):  
Fazlurrahman Khan ◽  
Hongsik Yu ◽  
Young-Mog Kim
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Chitosan Nanoparticles ◽  
Usnic Acid ◽  
Spherical Shape ◽  
Bacterial Cells ◽  
Persister Cells ◽  
Buffer Solution ◽  
Transmission Electron ◽  
Average Size

The present study aimed to prepare usnic acid (UA)-loaded chitosan (CS) nanoparticles (UA-CS NPs) and evaluate its antibacterial activity against biofilm-forming pathogenic bacteria. UA-CS NPs were prepared through simple ionic gelification of UA with CS, and further characterized using Fourier transform infrared spectroscopy, X-ray diffraction, and field-emission transmission electron microscopy. The UA-CS NPs presented a loading capacity (LC) of 5.2%, encapsulation efficiency (EE) of 24%, and a spherical shape and rough surface. The maximum release of UA was higher in pH 1.2 buffer solution as compared to that in pH 6.8 and 7.4 buffer solution. The average size and zeta potential of the UA-CS NPs was 311.5 ± 49.9 nm in diameter and +27.3 ± 0.8 mV, respectively. The newly prepared UA-CS NPs exhibited antibacterial activity against persister cells obtained from the stationary phase in batch culture, mature biofilms, and antibiotic-induced gram-positive and gram-negative pathogenic bacteria. Exposure of sub-inhibitory concentrations of UA-CS NPs to the bacterial cells resulted in a change in morphology. The present study suggests an alternative method for the application of UA into nanoparticles. Furthermore, the anti-persister activity of UA-CS NPs may be another possible strategy for the treatment of infections caused by biofilm-forming pathogenic bacteria.

scholarly journals Green Synthesized Silver Nanoparticles Immobilized on Activated Carbon Nanoparticles: Antibacterial Activity Enhancement Study and Its Application on Textiles Fabrics

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3790
Author(s):  
Pratama Jujur Wibawa ◽  
Muhammad Nur ◽  
Mukhammad Asy’ari ◽  
Wijanarka Wijanarka ◽  
Heru Susanto ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Activated Carbon ◽  
Aloe Vera ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
E Coli ◽  
Transmission Electron ◽  
Average Size ◽  
Green Synthesized Silver Nanoparticles

This research aimed to enhance the antibacterial activity of silver nanoparticles (AgNPs) synthesized from silver nitrate (AgNO3) using aloe vera extract. It was performed by means of incorporating AgNPs on an activated carbon nanoparticle (ACNPs) under ultrasonic agitation (40 kHz, 2 × 50 watt) for 30 min in an aqueous colloidal medium. The successful AgNPs synthesis was clarified with both Ultraviolet-Visible (UV-Vis) and Fourier Transform Infrared (FTIR) spectrophotometers. The successful AgNPs–ACNPs incorporation and its particle size analysis was performed using Transmission Electron Microscope (TEM). The brown color suspension generation and UV-Vis’s spectra maximum wavelength at around 480 nm confirmed the existence of AgNPs. The particle sizes of the produced AgNPs were about 5 to 10 nm in the majority number, which collectively surrounded the aloe vera extract secondary metabolites formed core-shell like nanostructure of 8.20 ± 2.05 nm in average size, while ACNPs themselves were about 20.10 ± 1.52 nm in average size formed particles cluster, and 48.00 ± 8.37 nm in average size as stacking of other particles. The antibacterial activity of the synthesized AgNPs and AgNPs-immobilized ACNPs was 57.58% and 63.64%, respectively (for E. coli); 61.25%, and 93.49%, respectively (for S. aureus). In addition, when the AgNPs-immobilized ACNPs material was coated on the cotton and polyester fabrics, the antibacterial activity of the materials changed, becoming 19.23% (cotton; E. coli), 31.73% (polyester; E. coli), 13.36% (cotton; S. aureus), 21.15% (polyester; S. aureus).

Synthesis and Characterization of SiO2@Y2MoO6:Eu3+ Core–Shell Structured Spherical Phosphors by Sol–Gel Process

2016 ◽  
Vol 16 (4) ◽  
pp. 3914-3920 ◽  
Author(s):  
G. Z Li ◽  
F. H Liu ◽  
Z. S Chu ◽  
D. M Wu ◽  
L. B Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Annealing Temperature ◽  
Uv Light ◽  
Sol Gel ◽  
Spherical Shape ◽  
Core Shell ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Average Size

SiO2@Y2MoO6:Eu3+ core–shell phosphors were prepared by the sol–gel process. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectra (EDS), transmission electron microscopy (TEM), photoluminescence (PL) spectra as well as kinetic decays were used to characterize the resulting SiO2@Y2MoO6:Eu3+ core–shell phosphors. The XRD results demonstrated that the Y2MoO6:Eu3+ layers on the SiO2 spheres crystallized after being annealed at 700 °C and the crystallinity increased with raising the annealing temperature. The obtained core–shell phosphors have spherical shape with narrow size distribution (average size ca. 640 nm), non-agglomeration, and smooth surface. The thickness of the Y2MoO6:Eu3+ shells on the SiO2 cores could be easily tailored by varying the number of deposition cycles (70 nm for four deposition cycles). The Eu3+ shows a strong PL emission (dominated by 5D0–7F2 red emission at 614 nm) under the excitation of 347 nm UV light. The PL intensity of Eu3+ increases with increasing the annealing temperature and the number of coating cycles.

Antimicrobial Activity of O-Carboxymethyl Chitosan Nanofibers Containing Silver Nanoparticles Synthesized by Green Method

2016 ◽  
Vol 40 ◽  
pp. 136-145 ◽  
Author(s):  
Metwally Ezzat ◽  
Mohammed Ghanim ◽  
Hassan Nageh ◽  
Ahmed H. Hassanin ◽  
Ahmed Abdel-Moneim
Keyword(s):  
Antibacterial Activity ◽  
Wound Dressing ◽  
Pathogenic Bacteria ◽  
Reaction Times ◽  
Carboxymethyl Chitosan ◽  
Diffusion Method ◽  
Ag Nps ◽  
High Antibacterial Activity ◽  
Transmission Electron ◽  
Bacteria And Fungi

New green synthesis of Ag-nanoparticles (Ag-NPs) using O-Carboxymethyl Chitosan (O-CMCs) as stabilizing agent and ascorbic acid as reducing agent was achieved. The reaction was carried out in an autoclave at a pressure of 0.12 MPa and a temperature of 120°C at varying concentrations of solution precursors and different reaction times. The size, shape and structure of Ag-NPs were measured using transmission electron microscope (TEM), X-Ray Diffraction (XRD), FT-IR and UV spectrophotometers. The Ag-NPs stabilized in O-CMCs were blended with polyvinyl alcohol (PVA) polymer solution and then electrospun to produce wound dressing nanofibers with high antibacterial activity. The morphological study of O-CMCs/ PVA/Ag-NPs nanofiber membranes was characterized using SEM. Finally, the release behavior of Ag-NPs from these nanofibers was examined and the antibacterial activity was measured against some skin pathogenic bacteria and fungi using the agar diffusion method. The newly developed membranes show a unique antibacterial activity against the tested strains and were presented as promising active wound dressing materials in medical applications.

Preparation and Optimization of a Live Newcastle Disease Virus Vaccine Encapsulated in Chitosan Nanoparticles

2013 ◽  
Vol 662 ◽  
pp. 149-152
Author(s):  
Yan Hao ◽  
Hao Wu ◽  
Wei Li ◽  
Xiao Mei Luo ◽  
Kai Zhao
Keyword(s):  
Virus Vaccine ◽  
Chitosan Nanoparticles ◽  
Influence Factors ◽  
Spherical Shape ◽  
Entrapment Efficiency ◽  
Physicochemical Characteristics ◽  
Ionic Gelation ◽  
Synthetic Vaccines ◽  
Average Size ◽  
Newcastle Disease Virus Vaccine

In this study, the researcher’s interest is focused on establishing a model with La Sota live vaccine immobilized into chitosan, which was prepared using a ionic gelation method. The formulation, preparation procedure, influence factors, physicochemical characteristics were evaluated. The results of study demonstrate that the NDV-CS-NPs have been produced with suitable size, morphous regulation, extremely spherical shape, regular and well-distributed. The NDV-CS-NPs produced by the optimal formulation were average size (371.1nm) and proper zata potential (+2.84 mV). The entrapment efficiency was (74±3.7) %. It can provide a new useful information for the development and evaluation of synthetic vaccines.

scholarly journals Biomimetic Synthesis of Silver Nanoparticles from Aqueous Extract of Saraca indica and its Profound Antibacterial Activity

2020 ◽  
Vol 11 (1) ◽  
pp. 8110-8120
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Aqueous Extract ◽  
Silver Nanoparticle ◽  
Pathogenic Bacteria ◽  
Drug Formulation ◽  
Biomimetic Synthesis ◽  
Visible Absorption ◽  
The Stability ◽  
Average Size

The present findings were focused on green synthesis of silver nanoparticles through an aqueous extract of Saraca indica. The stability of the nanoparticle was achieved through the optimization of physico-chemical parameters. The sharp UV-visible absorption maximum at 400 was observed for biological synthesized silver nanoparticles. The spectroscopic analysis was thus used to assess the formation of silver nanoparticles. The AFM analysis did analyze the morphology of the nanocomposite, which was further confirmed through TEM micrograph. The electron micrograph image discloses that silver nanoparticles were polydispersed and dominantly as spherical with size ranges from 40nm to 100nm. The average size distribution was 49nm. The chemical reductions of Ag+ ions were further confirmed through FTIR. The biogenic silver nanoparticle and their drug formulation showed profound antibacterial activity against pathogenic bacteria. The flavonoids rich binding of silver nanoparticle showed great medicinal potential and can be used for the treatment of several harmful infectious diseases. Hence, plant-based metal nanoparticles meet the demand for less toxic formulation during drug development and its delivery.

POLYETHYLENE GLYCOL-FUNCTIONALIZED MAGNETIC (Fe3O4) NANOPARTICLES: A GOOD METHOD FOR A SUCCESSFUL ANTIBACTERIAL THERAPEUTIC AGENT VIA DAMAGE DNA MOLECULE

2019 ◽  
Vol 26 (10) ◽  
pp. 1950079 ◽  
Author(s):  
WALEED K. ABDUL KADHIM ◽  
UDAY M. NAYEF ◽  
MAJID S. JABIR
Keyword(s):  
Cell Wall ◽  
Antibacterial Activity ◽  
Polyethylene Glycol ◽  
Nucleic Acid ◽  
Antibacterial Agent ◽  
Bacterial Species ◽  
Good Method ◽  
Diffusion Method ◽  
Bacterial Cells ◽  
Average Size

Magnetite (Fe3O4) nanoparticles (MPs) capped with polyethylene glycol (PEG) were prepared by a hydrothermal method, and their antibacterial activity was examined against Staphylococcus aureus, Escherichia coli and Psudomonas aeruginosa. The functionalized NPs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), Fourier transform infrared (FTIR) spectroscopy, and Thermogravimetry (TG). The average size of the Fe3O4 was in the range 9–20[Formula: see text]nm, while the functionalized PEG–Fe3O4 had an average size of 5–15[Formula: see text]nm. The PEG–Fe3O4 exhibited superparamagnetism and high saturation magnetization at room temperature. The antibacterial activity of the Fe3O4 and PEG–Fe3O4 were evaluated against E. coli, S. aureus, and P. aeruginosa using the agar well diffusion method. The changes in the morphology of the studied bacterial species were observed via SEM, while the mode of action of the studied agents was determined via the detection of reactive oxygen species (ROS) using Acridine orange-ethidium bromide (AO/EtBr) staining method. The results showed that PEG-functionalized magnetic (Fe3O4) NPs as a novel DNA-mediated antibacterial agent. The PEG–Fe3O4 NPs were observed to destroy the bacterial cells by permeating the bacterial nucleic acid and cytoplasmic membrane, resulting in the loss of cell-wall integrity, nucleic acid damage, and increased cell-wall permeability. The PEG–Fe3O4 NPs could serve as a potential antibacterial agent in future biomedical and pharmaceutical applications.

The Effect of Ultrasound Wave on Levothyroxine Release from Chitosan Nanoparticles

2013 ◽  
Vol 829 ◽  
pp. 284-288
Author(s):  
Elham Rostami ◽  
Soheila Kashanian ◽  
Mehran Askari
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Chitosan Nanoparticles ◽  
Spherical Shape ◽  
Correlation Spectroscopy ◽  
Ultrasound Wave ◽  
Non Invasive ◽  
Ionic Crosslinking ◽  
Transmission Electron ◽  
Shape Of Nanoparticles

A nanoparticle polymer has been developed as a potential platform for drug delivery. Chitosan nanoparticles were prepared with tripolyphosphate (TPP) by the ionic crosslinking method. The particle size of chitosan nanoparticles was in the range of 190-250 nm and encapsulation efficiencies of levothyroxine were 85%. The particle size was determined by photon correlation spectroscopy (PCS). Shape and surface morphology were determined by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). They revealed fairly spherical shape of nanoparticles. A non-invasive way to deliver drugs to the deepest parts of the human body is ultrasound. To study how ultrasound causes levothyroxine to be released from chitosan nanoparticles, cumulative release was examined. In this report, we explore the effect of ultrasound and tripolyphosphate (TPP) concentration on release behavior of levothyroxine from chitosan nanoparticles. The drug release from chitosan nanoparticles was enhanced using the ultrasound wave.

scholarly journals Fortunella japonica extract as a reducing agent for green synthesis of silver nanoparticles

2018 ◽  
Vol 7 (3) ◽  
pp. 1570
Author(s):  
Nguyen Phung Anh ◽  
Truong Thi Ai Mi ◽  
Duong Huynh Thanh Linh ◽  
Nguyen Thi Thuy Van ◽  
Hoang Tien Cuong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Volume Ratio ◽  
Diffusion Method ◽  
High Antibacterial Activity ◽  
Agno3 Solution ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Average Size

A rapid way of synthesizing silver nanoparticles (AgNPs) by treating Ag+ ions with a green Fortunella Japonica (F.J.) extract as a combined reducing and stabilizing agent was investigated. The reaction solutions were monitored using UV-Vis spectroscopy, the size and shape of crystals were determined by scanning electron microscopy and transmission electron microscopy, the crystalline phases of AgNPs were presented by X–ray diffraction, and the relation of nanoparticles with Fortunella Japonica extract was confirmed using fourier transform infrared spectroscopy. The results indicated that no formation of AgNPs had taken place in the dark during 24 hours at room temperature and 40 oC. Meanwhile, it was found that the rate of AgNPs formation increased rapidly under the sunlight. The effects of the synthesis factors on the AgNPs formation were investigated. The suitable conditions for the synthesis of AgNPs using F.J. extract were determined as follows: F.J. extract was mixed with AgNO3 1.75 mM solution with the volume ratio of 3.5 AgNO3 solution/1.5 F.J. Extract, stirred 300 rpm for 150 minutes at 40 oC under sunlight illumination. At these conditions, AgNPs showed high crystalline structure with the average size of 15.9 nm. The antibacterial activity of silver nanoparticles was determined by agar well diffusion method against E. coli and B. subtilis bacteria. The green synthesized AgNPs performed high antibacterial activity against both bacteria.  

scholarly journals Structural and optical investigation of CdSe quantum dots

2013 ◽  
Vol 8 (2) ◽  
pp. 83-88
Author(s):  
Neupane Dipesh
Keyword(s):  
Quantum Dots ◽  
Large Scale ◽  
Room Temperature ◽  
Spherical Shape ◽  
Cdse Quantum Dots ◽  
Optical Investigation ◽  
X Ray ◽  
Transmission Electron ◽  
Engineering And Technology ◽  
Average Size

CdSe semiconducting Quantum dots were prepared by a chemical method at a room temperature. X-ray powder diffraction and transmission electron microscope measurements conformed a hexagonal cubic crystalline phase of Cdse semiconducting Quantum dots of about 15 nm average size with nearly spherical shape. The absorption and photoluminescence spectra of the CdSe quantum dots were strongly shown blue shifted due to size quantization. The present study describes a simultaneous and highly reproducible large scale synthesis of highly luminescent CdSe Quantum dots. Kathmandu University Journal of Science, Engineering and Technology Vol. 8, No. II, December, 2012, 83-88 DOI: http://dx.doi.org/10.3126/kuset.v8i2.7329

scholarly journals An Investigation on the Antiproliferative and Antibacterial Activity of Silver Nanoparticles of Quercus infectoria and Daucus carota subsp sativum

2021 ◽  
pp. 33-46
Author(s):  
S. Prathimaa ◽  
J. Anbumalarmathi ◽  
S. Aruna Sharmili
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Daucus Carota ◽  
Spherical Shape ◽  
Cost Effective ◽  
Surface Plasma Resonance ◽  
Electron Microscopic ◽  
Total Antioxidant ◽  
Average Size ◽  
Quercus Infectoria

Plant mediated fabrication of nanoparticles and nanomaterials are gaining momentum as it is eco-friendly and cost-effective. In the present study, we synthesis of Silver nanoparticles using aqueous extract of  Quercus infectoria nuts and Daucus carota subsp sativum leaves. The surface plasma resonance at 417 and 450 nm for Q. infectoria and D. carota respectively confirmed the formation of AgNPs. Scanning Electron Microscopic (SEM) confirmed the spherical shape of the nanoparticles, which had an average size of 67.5 nm and 49.2 nm for Q. infectoria nanoparticles (QAgNPs)and D. carota nanoparticles (DAgNPs). The elemental composition by Energy-Dispersive X-ray analysis of the nanoparticle showed an atomic percentage of silver as 73.64 % and 75.93% for Q. infectoria and D. carota.FT- IR analysis of the plant extracts and synthesized silver nanoparticles showed the presence of various functional groups. The total antioxidant activity of QAgNPs was 81.18% and that of DAgNPs was 73.36%. The QAgNPs and DAgNPs exhibited antibacterial activity against B. subtilis, E. coli and S. aureus. The percentage of cell viability for QAgNPs and DAgNPs assessed using HeLa cells was 21.1% and 6% respectively.

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