scholarly journals Antibacterial Additive for Polystyrene Based on Silver Nanoparticles Supported on Titanium Dioxide

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Miguel A. Waldo-Mendoza ◽  
Lucía Martínez-Jothar ◽  
Socorro Oros-Ruiz ◽  
E. G. Villabona-Leal ◽  
Luis Manuel Céspedes-Covarrubias ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Titanium Dioxide ◽  
Titanium Dioxide Nanoparticles ◽  
Antibacterial Properties ◽  
Precipitation Method ◽  
Concentration Limit ◽  
Injection Molding Process ◽  
Molding Process ◽  
Plate Method

Silver nanoparticles supported on titanium dioxide nanoparticles (Ag/TiO2) were incorporated and evaluated as antibacterial additive for polystyrene materials. These particles were synthesized using a deposition-precipitation method by adding silver nitrate as metallic precursor, sodium hydroxide as reducing agent, and commercial TiO2 (P25) as support. Rectangular pieces of polystyrene (PS) containing 100, 300, 500, and 700 ppm (wt.%) of the additive were made using an extrusion-injection molding process, and they were evaluated for their antibacterial properties against Escherichia coli using the Pour Plate method. Particles were distributed on the PS surface, and PS pieces presented a good antibacterial efficiency at 100, 300, and 500 ppm and decreased for 700 ppm due to an additive agglomeration on the PS surface. These results validate the antibacterial properties of Ag/TiO2, determine a concentration limit at which the additive is well distributed on the PS surface, and assess the importance of Ag in this system.

scholarly journals Metabolomic and proteomic investigations of impacts of titanium dioxide nanoparticles on Escherichia coli

PLoS ONE ◽  
2017 ◽  
Vol 12 (6) ◽  
pp. e0178437 ◽  
Author(s):  
Mariane Planchon ◽  
Thibaut Léger ◽  
Olivier Spalla ◽  
Gaspard Huber ◽  
Roselyne Ferrari
Keyword(s):  
Escherichia Coli ◽  
Titanium Dioxide ◽  
Titanium Dioxide Nanoparticles

scholarly journals Evaluation of Nanocomposite Made of Polylactic Acid and Nanocellulose from Carrot Pomace Modified with Silver Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 812 ◽  
Author(s):  
Monika Szymańska-Chargot ◽  
Monika Chylińska ◽  
Piotr M. Pieczywek ◽  
Anna Walkiewicz ◽  
Giorgia Pertile ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mechanical Properties ◽  
Carbon Dioxide ◽  
Silver Nanoparticles ◽  
Polylactic Acid ◽  
Cellulose Nanofibrils ◽  
Antibacterial Properties ◽  
Young Modulus ◽  
Transmission Rates ◽  
Degradation Temperature

In this research, it was proposed to use carrot cellulose nanofibrils (CCNF) isolated from carrot pomace modified with silver nanoparticles (AgNPs) as a filler of polylactic acid (PLA) composites matrix. The new procedure was based on two steps: first, the preparation of nanocellulose modified with metal nanoparticles, and then the combination with PLA. Two concentrations—0.25 mM and 2 mM—of AgNO3 were used to modify CCNF. Then, PLA was mixed with the filler (CCNF/AgNPs) in two proportions 99:1 and 96:4. The influence of CCNF/AgNPs on mechanical, hydrophilic, thermal, and antibacterial properties of obtained nanocomposites was evaluated. The greatest improvement of mechanical properties was observed for composite containing CCNF with 2 mM of AgNPs, which obtained the lowest Young modulus and highest strain at break. The degradation temperature was lower for PLA with CCNF/AgNPs, but crystallization temperature wasn’t influenced. The addition of CCNF/AgNPs also increased hydrophilicity. The transmission rates of oxygen, nitrogen, and carbon dioxide also increased after the addition of CCNF/AgNPs to PLA. The antibacterial function against Escherichia coli and Bacillus cereus was obtained after the addition of AgNPs but only at the contact surface with the material made, suggesting the lack of migration of nanoparticles from the composite.

scholarly journals Titanium Dioxide Nanoparticles Elicit Lower Direct Inhibitory Effect on Human Gut Microbiota Than Silver Nanoparticles

2019 ◽  
Vol 172 (2) ◽  
pp. 411-416 ◽  
Author(s):  
Richard T Agans ◽  
Alex Gordon ◽  
Saber Hussain ◽  
Oleg Paliy
Keyword(s):  
Silver Nanoparticles ◽  
Titanium Dioxide ◽  
Gut Microbiota ◽  
Titanium Dioxide Nanoparticles ◽  
Close Association ◽  
Community Diversity ◽  
Bacterial Cells ◽  
Human Gut ◽  
Human Gut Microbiota

Abstract Due to continued technological development, people increasingly come in contact with engineered nanomaterials (ENMs) that are now used in foods and many industrial applications. Many ENMs have historically been shown to possess antimicrobial properties, which has sparked concern for how dietary nanomaterials impact gastrointestinal health via microbial dysbiosis. We employed an in vitro Human Gut Simulator system to examine interactions of dietary nano titanium dioxide (TiO2) with human gut microbiota. Electron microscopy indicated a close association of TiO2 particles with bacterial cells. Addition of TiO2 to microbial communities led to a modest reduction in community density but had no impact on community diversity and evenness. In contrast, administration of known antimicrobial silver nanoparticles (NPs) in a control experiment resulted in a drastic reduction of population density. In both cases, communities recovered once the addition of nanomaterials was ceased. Constrained ordination analysis of community profiles revealed that simulated colonic region was the primary determinant of microbiota composition. Accordingly, predicted community functional capacity and measured production of short-chain fatty acids were not changed significantly upon microbiota exposure to TiO2. We conclude that tested TiO2 NPs have limited direct effect on human gut microbiota.

Impacts of titanium dioxide nanoparticles on transformation of silver nanoparticles in aquatic environments

2018 ◽  
Vol 5 (5) ◽  
pp. 1191-1199 ◽  
Author(s):  
Yinqing Zhang ◽  
Liwen Qiang ◽  
Yuting Yuan ◽  
Wei Wu ◽  
Binbin Sun ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Titanium Dioxide ◽  
Titanium Dioxide Nanoparticles ◽  
Aquatic Environments ◽  
Oxidative Dissolution ◽  
Sunlight Irradiation

Under sunlight irradiation, titanium dioxide nanoparticles could promote the oxidative dissolution of silver nanoparticles in aquatic environments.

scholarly journals Does the Antibacterial Activity of Silver Nanoparticles Depend on the Shape of the Nanoparticle? A Study of the Gram-Negative Bacterium Escherichia coli

2007 ◽  
Vol 73 (6) ◽  
pp. 1712-1720 ◽  
Author(s):  
Sukdeb Pal ◽  
Yu Kyung Tak ◽  
Joon Myong Song
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Antibacterial Properties ◽  
Negative Bacterium ◽  
Gram Negative ◽  
Energy Filtering ◽  
Transmission Electron ◽  
Triangular Silver Nanoplates ◽  
Liquid Systems ◽  
Biocidal Property

ABSTRACT In this work we investigated the antibacterial properties of differently shaped silver nanoparticles against the gram-negative bacterium Escherichia coli, both in liquid systems and on agar plates. Energy-filtering transmission electron microscopy images revealed considerable changes in the cell membranes upon treatment, resulting in cell death. Truncated triangular silver nanoplates with a {111} lattice plane as the basal plane displayed the strongest biocidal action, compared with spherical and rod-shaped nanoparticles and with Ag+ (in the form of AgNO3). It is proposed that nanoscale size and the presence of a {111} plane combine to promote this biocidal property. To our knowledge, this is the first comparative study on the bactericidal properties of silver nanoparticles of different shapes, and our results demonstrate that silver nanoparticles undergo a shape-dependent interaction with the gram-negative organism E. coli.

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