Guy Applerot

Sonochemical coating of silver nanoparticles on textile fabrics (nylon, polyester and cotton) and their antibacterial activity

Silver nanoparticles were synthesized and deposited on different types of fabrics using ultrasound irradiation. The structure of silver-fabric composites was studied by physico-chemical methods. The mechanism of the strong adhesion of silver nanoparticles to the fibers is discussed. The excellent antibacterial activity of the Ag-fabric composite against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) cultures was demonstrated.

Antibacterial Properties of an In Situ Generated and Simultaneously Deposited Nanocrystalline ZnO on Fabrics

Zinc oxide (ZnO) nanoparticles were synthesized and deposited on the surface of cotton fabrics using ultrasound irradiation. Optimization of the process resulted in a homogeneous distribution of ZnO nanocrystals, 30 nm in size, on the fabric surface. The mechanism of the ultrasound-assisted coating was proposed. The antibacterial activities of the ZnO-fabric composite were tested against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) cultures. A significant bactericidal effect, even in a 0.75% coated fabric (wt %), was demonstrated.

Understanding the Antibacterial Mechanism of CuO Nanoparticles: Revealing the Route of Induced Oxidative Stress

To date, there is still a lack of definite knowledge regarding the interaction of CuO nanoparticles with bacteria and the possible permeation of the nanoparticles into bacterial cells. This study was aimed at shedding light on the size-dependent (from the microscale down to the small nanoscale) antibacterial activity of CuO. The potent antibacterial activity of CuO nanoparticles was found to be due to ROS-generation by the nanoparticles attached to the bacterial cells, which in turn provoked an enhancement of the intracellular oxidative stress. This paradigm was confirmed by several assays such as lipid peroxidation and reporter strains of oxidative stress. Furthermore, electron microscopy indicated that the small nanoparticles of CuO penetrated the cells. Collectively, the results reported herein may reconcile conflicting concepts in the literature concerning the antibacterial mechanism of CuO nanoparticles, as well as highlight the potential for developing sustainable CuO nanoparticles-based devices for inhibiting bacterial infections.

ZnO nanoparticle-coated surfaces inhibit bacterial biofilm formation and increase antibiotic susceptibility

Nanotechnology is providing new ways to manipulate the structure and chemistry of surfaces to inhibit bacterial colonization. In this study, we evaluated the ability of glass slides coated with zinc oxide (ZnO) nanoparticles to restrict the biofilm formation of common bacterial pathogens. The generation of hydroxyl radicals, originating from the coated surface, was found to play a key role in antibiofilm activity. Furthermore, we evaluated the ability of the nanoparticle coating to enhance the antibacterial activity of commonly-used antibiotics. The ZnO nanoparticles were synthesized and deposited on the surface of glass slides using a one-step ultrasound irradiation process. Several physico-chemical surface characterization methods were performed to prove the long-term stability and homogenity of the coated films. Collectively, our findings may open a new door for utilizing ZnO nanoparticle films as antibiofilm coating of surfaces, thus providing a versatile platform for a wide range of applications both in medical and industrial settings, all of which are prone to bacterial colonization.

A One‐Step Process for the Antimicrobial Finishing of Textiles with Crystalline TiO2 Nanoparticles

Titanium oxide (TiO(2)) nanoparticles (NPs) in their two forms, anatase and rutile, were synthesized and deposited onto the surface of cotton fabrics by using ultrasonic irradiation. The structure and morphology of the nanoparticles were analyzed by using characterization methods such as XRD, TEM, STEM, and EDS. The antimicrobial activities of the TiO(2)-cotton composites were tested against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) strains, as well as against Candida albicans. Significant antimicrobial effect was observed, mainly against Staphylococcus aureus. In addition, the combination of visible light and TiO(2) NPs showed enhanced antimicrobial activity.

Decorating Parylene-Coated Glass with ZnO Nanoparticles for Antibacterial Applications: A Comparative Study of Sonochemical, Microwave, and Microwave-Plasma Coating Routes

A glass substrate, coated with a Parylene film, was coated with ZnO by three different methods: ultrasound, microwave, and microwave-plasma irradiation. These coating modes are simple, efficient, and environmentally friendly one-step processes. The structure of the coated products was characterized and compared using methods such as XRD, HR-SEM, EDS, RBS, and optical spectroscopy. Coating by ZnO nanoparticles was achieved for all three approaches. The products were found to differ in their particle sizes, coating thickness, and depth of penetration. All of the ZnO-Parylene-glass composites demonstrated a significant antibacterial activity against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) strains.