scholarly journals Biopolymer Composites with Ti/Au Nanostructures and Their Antibacterial Properties

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 826
Author(s):  
Petr Slepička ◽  
Dominik Fajstavr ◽  
Markéta Krejčová ◽  
Silvie Rimpelová ◽  
Nikola Slepičková Kasálková ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Large Scale ◽  
Antibacterial Properties ◽  
Chemical Properties ◽  
Laser Confocal Microscopy ◽  
Cathode Sputtering ◽  
X Ray ◽  
E Coli ◽  
Atomic Force

In this study, we have aimed at the preparation and characterization of poly-l-lactic acid (PLLA) composites with antibacterial properties. Thin bilayers of titanium and gold of various thickness ratios were deposited on PLLA by a cathode sputtering method; selected samples were subsequently thermally treated. The surface morphology of the prepared composites was studied by atomic force, scanning electron, and laser confocal microscopy. The chemical properties of the composites were determined by X-ray photoelectron and energy-dispersive X-ray spectroscopy in combination with contact angle and zeta potential analyses. The antibacterial properties of selected samples were examined against a Gram-negative bacterial strain of E. coli. We have found that a certain combination of Au and Ti nanolayers in combination with heat treatment leads to the formation of a unique wrinkled pattern. Moreover, we have developed a simple technique by which a large-scale sample modification can be easily produced. The dimensions of wrinkles can be tailored by the sequence and thickness of the deposited metals. A selected combination of gold, titanium, and heat treatment led to the formation of a nanowrinkled pattern with excellent antibacterial properties.

scholarly journals Sustainable Nanotechnologies for Curative and Preventive Wood Deacidification Treatments: An Eco-Friendly and Innovative Approach

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1744
Author(s):  
Giuliana Taglieri ◽  
Valeria Daniele ◽  
Ludovico Macera ◽  
Ralf Schweins ◽  
Sandro Zorzi ◽  
...  
Keyword(s):  
Small Angle Neutron Scattering ◽  
Large Scale ◽  
Alkaline Ph ◽  
X Ray Diffraction ◽  
Satisfactory Solution ◽  
X Ray ◽  
Atomic Force ◽  
Ancient Wood ◽  
First Time

Waterlogged wooden artifacts represent an important historical legacy of our past. They are very fragile, especially due to the severe phenomenon of acidification that may occur in the presence of acid precursors. To date, a satisfactory solution for the deacidification of ancient wood on a large scale has still not been found. In this paper, we propose, for the first time, eco-friendly curative and preventive treatments using nanoparticles (NPs) of earth alkaline hydroxides dispersed in water and produced on a large scale. We present the characterization of the NPs (by X-ray diffraction, atomic-force and electron microscopy, and small-angle neutron scattering), together with the study of the deacidification efficiency of our treatments. We demonstrate that all our treatments are very effective for both curative and preventive aims, able to assure an almost neutral or slightly alkaline pH of the treated woods. Furthermore, the use of water as a solvent paves the way for large-scale and eco-friendly applications which avoid substances that are harmful for the environment and for human health.

scholarly journals Structural, Morphological and Antimicrobial Study of ZnO/Ag Nanoparticles

2020 ◽  
Vol 13 (4) ◽  
pp. 1645-1652
Author(s):  
Richa Sharma ◽  
Suresh Kumar ◽  
Prem Singh ◽  
Shikha Kapila
Keyword(s):  
Metal Oxide ◽  
Ag Nanoparticles ◽  
Metal Oxide Nanoparticles ◽  
Antibacterial Properties ◽  
Chemical Properties ◽  
Single Step ◽  
Oxide Nanoparticles ◽  
Bacterial Strains ◽  
X Ray ◽  
E Coli

Metal oxide nanoparticles gain attention in the field of biomedical applications because of their unique physico-chemical properties and emerging out as an alternative to antibiotics. The major cause of most of the human diseases is the bacterial infection. However, antibiotics used in the cure show other complications to human health. Therefore, the purpose of the present work is to investigate the antibacterial properties of ZnO/Ag nanoparticles on the test bacterial strains, Escherichia coli (E. coli). ZnO/Ag nanoparticles are synthesized using surfactant mediated route in a single step and double step procedure. Here, CTAB and hydrazine hydrate used as a surfactant and reducing agents respectively. The synthesized nanoparticles are characterized by x-ray diffraction, scanning electron microscopy and energy dispersive x-ray spectroscopy for structure, morphology and compositional properties. The antibacterial activities of these nanoparticles are also studied using the agar-well diffusion technique. The result analysis shows that synthesized nanopaticles are spherical in shape, having particles of the size 6 nm and 13 nm in the desired elemental composition. ZnO/Ag nanoparticles possessed a strong antibacterial effect against E. coli. This study signifies that ZnO/Ag metal oxide nanoparticles exhibit stronger antimicrobial activity against pathogen bacteria E. coli which may works effectively on the antibacterial and antifungal infections.

scholarly journals Glutathione Reductase-Mediated Synthesis of Tellurium-Containing Nanostructures Exhibiting Antibacterial Properties

2014 ◽  
Vol 80 (22) ◽  
pp. 7061-7070 ◽  
Author(s):  
Benoit Pugin ◽  
Fabián A. Cornejo ◽  
Pablo Muñoz-Díaz ◽  
Claudia M. Muñoz-Villagrán ◽  
Joaquín I. Vargas-Pérez ◽  
...  
Keyword(s):  
Glutathione Reductase ◽  
Antibacterial Properties ◽  
Chemical Properties ◽  
Content Type ◽  
E Coli ◽  
Biochemical Approach ◽  
Reducing Activity ◽  
Physical And Chemical ◽  
The Antarctic

ABSTRACTTellurium, a metalloid belonging to group 16 of the periodic table, displays very interesting physical and chemical properties and lately has attracted significant attention for its use in nanotechnology. In this context, the use of microorganisms for synthesizing nanostructures emerges as an eco-friendly and exciting approach compared to their chemical synthesis. To generate Te-containing nanostructures, bacteria enzymatically reduce tellurite to elemental tellurium. In this work, using a classic biochemical approach, we looked for a novel tellurite reductase from the Antarctic bacteriumPseudomonassp. strain BNF22 and used it to generate tellurium-containing nanostructures. A new tellurite reductase was identified as glutathione reductase, which was subsequently overproduced inEscherichia coli. The characterization of this enzyme showed that it is an NADPH-dependent tellurite reductase, with optimum reducing activity at 30°C and pH 9.0. Finally, the enzyme was able to generate Te-containing nanostructures, about 68 nm in size, which exhibit interesting antibacterial properties againstE. coli, with no apparent cytotoxicity against eukaryotic cells.

Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid-beta M1-42

2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra
Keyword(s):  
Amyloid Beta ◽  
Western Blots ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Set Up ◽  
Short Time

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.

Anin situatomic force microscope for normal-incidence nanofocus X-ray experiments

2016 ◽  
Vol 23 (5) ◽  
pp. 1110-1117 ◽  
Author(s):  
M. V. Vitorino ◽  
Y. Fuchs ◽  
T. Dane ◽  
M. S. Rodrigues ◽  
M. Rosenthal ◽  
...  
Keyword(s):  
Thin Film ◽  
Atomic Force Microscope ◽  
High Speed ◽  
Normal Incidence ◽  
Organic Thin Film ◽  
X Ray ◽  
Atomic Force ◽  
Synchrotron Beamlines

A compact high-speed X-ray atomic force microscope has been developed forin situuse in normal-incidence X-ray experiments on synchrotron beamlines, allowing for simultaneous characterization of samples in direct space with nanometric lateral resolution while employing nanofocused X-ray beams. In the present work the instrument is used to observe radiation damage effects produced by an intense X-ray nanobeam on a semiconducting organic thin film. The formation of micrometric holes induced by the beam occurring on a timescale of seconds is characterized.

scholarly journals The Physicochemical and Antibacterial Properties of Chitosan-Based Materials Modified with Phenolic Acids Irradiated by UVC Light

2021 ◽  
Vol 22 (12) ◽  
pp. 6472
Author(s):  
Beata Kaczmarek-Szczepańska ◽  
Marcin Wekwejt ◽  
Olha Mazur ◽  
Lidia Zasada ◽  
Anna Pałubicka ◽  
...  
Keyword(s):  
Thin Films ◽  
Antimicrobial Activity ◽  
Ferulic Acid ◽  
Phenolic Acid ◽  
Food Packaging ◽  
Antibacterial Properties ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After

This paper concerns the physicochemical properties of chitosan/phenolic acid thin films irradiated by ultraviolet radiation with wavelengths between 200 and 290 nm (UVC) light. We investigated the preparation and characterization of thin films based on chitosan (CTS) with tannic (TA), caffeic (CA) and ferulic acid (FA) addition as potential food-packaging materials. Such materials were then exposed to the UVC light (254 nm) for 1 and 2 h to perform the sterilization process. Different properties of thin films before and after irradiation were determined by various methods such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimeter (DSC), mechanical properties and by the surface free energy determination. Moreover, the antimicrobial activity of the films and their potential to reduce the risk of contamination was assessed. The results showed that the phenolic acid improving properties of chitosan-based films, short UVC radiation may be used as sterilization method for those films, and also that the addition of ferulic acid obtains effective antimicrobial activity, which have great benefit for food packing applications.

Infrared Characterization of PMMA-SiO2 Hybrid Glasses Obtained by Sol-Gel Process

2010 ◽  
Vol 1278 ◽  
Author(s):  
L.L. Díaz-Flores ◽  
A. S. López Rodríguez ◽  
P. SifuentesGallardo ◽  
M.A. Hernàndez Rivera ◽  
M.a Garnica Romo ◽  
...  
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Hybrid Coatings ◽  
Force Microscopy ◽  
Air Atmosphere ◽  
Atomic Force ◽  
Sol Gel Process ◽  
Traditional Process ◽  
And Chemical Properties

AbstractThis work is about the production of hybrid coatings of the system SiO2-PMMA (PMMA, polymethylmethacrylate). These materials have interesting mechanical and chemical properties useful for anticorrosive and wear resistance applications. SiO2-PMMA hybrids were obtained by the sol-gel traditional process, using tetraethylorthosilicate (TEOS) and methylmethacrylate (MMA) by Aldrich Co, as starting reagents. The SiO2:PMMA ratio was varied from 0:1 to about 1:1 at air atmosphere deposition. The coatings were obtained on acrylic sheets and silicon wafers. A diversity of coatings with chemical composition ranging from SiO2 and PMMA to obtain the SiO2-PMMA hybrids were obtained. Infrared (IR) and atomic force microscopy (AFM), were performed to determinate structural and morphological behavior.

Analysis of CoCrMo Surface Oxide Removal by Alumina Blasting before Porcelain Firing in Dental Restorations

2012 ◽  
Vol 730-732 ◽  
pp. 9-14 ◽  
Author(s):  
Bruno Henriques ◽  
Filipe Silva ◽  
Delfim Soares
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Chemical Composition ◽  
High Alumina ◽  
X Ray ◽  
Dental Restorations ◽  
Ceramic Bond ◽  
Xrf Scanning ◽  
Oxide Removal

The purpose of this work was to perform a chemical and mechanical characterization of a preoxidized CoCrMo alumina blasted surface. This is a commonly performed surface treatment used in metal-porcelain systems for dental restorations to remove oxides formed during preoxidation heat treatment from the metal’s surface. CoCrMo dental alloy’s specimens produced by lost wax process were examined in terms of chemical composition using X-Ray fluorescence spectroscopy (XRF), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS); in terms of mechanical characteristics through the means of a microhardness test and in terms of surface roughness using a profilometer. It was investigated the chemical composition of various surface conditions: non-preoxidized, preoxidized, ground oxidized surface and sandblasted oxidized surface. After alumina blasting, the oxides level on metal’s surface remained high. Alumina blasting treatment (Ø110 µm) produced an 84% increase of CoCrMo surface hardening and an increase in surface roughness (Ra=0.58 µm). It was found alumina contaminants on the metal’s surface. Therefore, it was concluded that alumina blasting do not entirely removes the oxide layer formed during preoxidation heat treatment. It produced a chemical and mechanical surface modification that can influence the metal-ceramic bond strength.

scholarly journals Synthesis of Metarhizium anisopliae–Chitosan Nanoparticles and Their Pathogenicity against Plutella xylostella (Linnaeus)

2021 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Jianhui Wu ◽  
Cailian Du ◽  
Jieming Zhang ◽  
Bo Yang ◽  
Andrew G. S. Cuthbertson ◽  
...  
Keyword(s):  
Plutella Xylostella ◽  
Metarhizium Anisopliae ◽  
Chitosan Nanoparticles ◽  
Analytical Techniques ◽  
X Ray ◽  
Synthesis Of Nanoparticles ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Analysis

Nanotechnology is increasingly being used in areas of pesticide production and pest management. This study reports the isolation and virulence of a new Metarhizium anisopliae isolate SM036, along with the synthesis and characterization of M. anisopliae–chitosan nanoparticles followed by studies on the efficacy of nanoparticles against Plutella xylostella. The newly identified strain proved pathogenic to P. xylostella under laboratory conditions. The characterization of M. anisopliae–chitosan nanoparticles through different analytical techniques showed the successful synthesis of nanoparticles. SEM and HRTEM images confirmed the synthesis of spherical-shaped nanoparticles; X-ray diffractogram showed strong peaks between 2θ values of 16–30°; and atomic force microscopy (AFM) analysis revealed a particle size of 75.83 nm for M. anisopliae–chitosan nanoparticles, respectively. The bioassay studies demonstrated that different concentrations of M. anisopliae–chitosan nanoparticles were highly effective against second instar P. xylostella under laboratory and semi-field conditions. These findings suggest that M. anisopliae–chitosan nanoparticles can potentially be used in biorational P. xylostella management programs.

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