scholarly journals Antibacterial effect of silver nanorings

2020 ◽  
Author(s):  
Sara González-Fernández ◽  
Víctor Lozano-Iturbe ◽  
Beatriz García ◽  
Luis J. Andrés ◽  
Mª Fe Menéndez ◽  
...  

Abstract Background: The emergence and expansion of antibiotic resistance makes it necessary to have alternative anti-infective agents, among which silver nanoparticles (AgNPs) display especially interesting properties. AgNPs carry out their antibacterial action through various molecular mechanisms, and the magnitude of the observed effect is dependent on multiple, not fully understood, aspects, particle shape being one of the most important. In this article, we conduct a study of the antibacterial effect of a recently described type of AgNP: silver nanorings (AgNRs), making comparisons with other alternative types of AgNP synthesized in parallel using the same methodology. Results: When they act on planktonic forms, AgNRs produce a smaller effect on the viability of different bacteria than nanoparticles with other structures although their effect on growth is more intense over a longer period. When their action on biofilms is analyzed, AgNRs show a greater concentration-dependent effect. In both cases it was observed that the effect on inhibition depends on the microbial species, but not its Gram positive or negative nature. Growth patterns in silver-resistant Salmonella strains suggest that AgNRs work through different mechanisms to other AgNPs. The antibacterial effect is also produced to some extent by the conditioning of culture media or water by contact with AgNPs but, at least over short periods of time, this is not due to the release of Ag ions. Conclusions: AgNRs constitute a new type of AgNP, whose antibacterial properties depend on their shape, and is capable of acting efficiently on both planktonic bacteria and biofilms.

2020 ◽  
Author(s):  
Sara González-Fernández ◽  
Víctor Lozano-Iturbe ◽  
Beatriz García ◽  
Luis J. Andrés ◽  
Mª Fe Menéndez ◽  
...  

Abstract Background: The emergence and expansion of antibiotic resistance makes it necessary to have alternative anti-infective agents, among which silver nanoparticles (AgNPs) display especially interesting properties. AgNPs carry out their antibacterial action through various molecular mechanisms, and the magnitude of the observed effect is dependent on multiple, not fully understood, aspects, particle shape being one of the most important. In this article, we conduct a study of the antibacterial effect of a recently described type of AgNP: silver nanorings (AgNRs), making comparisons with other alternative types of AgNP synthesized in parallel using the same methodology. Results: When they act on planktonic forms, AgNRs produce a smaller effect on the viability of different bacteria than nanoparticles with other structures although their effect on growth is more intense over a longer period. When their action on biofilms is analyzed, AgNRs show a greater concentration-dependent effect. In both cases it was observed that the effect on inhibition depends on the microbial species, but not its Gram positive or negative nature. Growth patterns in silver-resistant Salmonella strains suggest that AgNRs work through different mechanisms to other AgNPs. The antibacterial effect is also produced to some extent by the conditioning of culture media or water by contact with AgNPs but, at least over short periods of time, this is not due to the release of Ag ions. Conclusions: AgNRs constitute a new type of AgNP, whose antibacterial properties depend on their shape, and is capable of acting efficiently on both planktonic bacteria and biofilms.


2020 ◽  
Author(s):  
Sara González-Fernández ◽  
Víctor Lozano-Iturbe ◽  
Beatriz García ◽  
Luis J. Andrés ◽  
Mª Fe Menéndez ◽  
...  

Abstract Background: The emergence and expansion of antibiotic resistance makes it necessary to have alternative anti-infective agents, among which silver nanoparticles (AgNPs) display especially interesting properties. AgNPs carry out their antibacterial action through various molecular mechanisms, and the magnitude of the observed effect is dependent on multiple, not fully understood, aspects, particle shape being one of the most important. In this article, we conduct a study of the antibacterial effect of a recently described type of AgNP: silver nanorings (AgNRs), making comparisons with other alternative types of AgNP synthesized in parallel using the same methodology.Results: When they act on planktonic forms, AgNRs produce a smaller effect on the viability of different bacteria than nanoparticles with other structures although their effect on growth is more intense over a longer period. When their action on biofilms is analyzed, AgNRs show a greater concentration-dependent effect. In both cases it was observed that the effect on inhibition depends on the microbial species, but not its Gram positive or negative nature. Growth patterns in silver-resistant Salmonella strains suggest that AgNRs work through different mechanisms to other AgNPs. The antibacterial effect is also produced to some extent by the conditioning of culture media or water by contact with AgNPs but, at least over short periods of time, this is not due to the release of Ag ions.Conclusions: AgNRs constitute a new type of AgNP, whose antibacterial properties depend on their shape, and is capable of acting efficiently on both planktonic bacteria and biofilms.


2020 ◽  
Author(s):  
Sara González-Fernández ◽  
Víctor Lozano-Iturbe ◽  
Beatriz García ◽  
Luis J. Andrés ◽  
Mª Fe Menéndez ◽  
...  

Abstract Background: The emergence and expansion of antibiotic resistance makes it necessary to have alternative anti-infective agents, among which silver nanoparticles (AgNPs) display especially interesting properties. AgNPs carry out their antibacterial action through various molecular mechanisms, and the magnitude of the observed effect is dependent on multiple, not fully understood, aspects, particle shape being one of the most important. In this article, we conduct a study of the antibacterial effect of a recently described type of AgNP: silver nanorings (AgNRs), making comparisons with other alternative types of AgNP synthesized in parallel using the same methodology.Results: When they act on planktonic forms, AgNRs produce a smaller effect on the viability of different bacteria than nanoparticles with other structures although their effect on growth is more intense over a longer period. When their action on biofilms is analyzed, AgNRs show a greater concentration-dependent effect. In both cases it was observed that the effect on inhibition depends on the microbial species, but not its Gram positive or negative nature. Growth patterns in silver-resistant Salmonella strains suggest that AgNRs work through different mechanisms to other AgNPs. The antibacterial effect is also produced to some extent by the conditioning of culture media or water by contact with AgNPs but, at least over short periods of time, this is not due to the release of Ag ions.Conclusions: AgNRs constitute a new type of AgNP, whose antibacterial properties depend on their shape, and is capable of acting efficiently on both planktonic bacteria and biofilms.


2019 ◽  
Author(s):  
Sara González-Fernández ◽  
Víctor Lozano-Iturbe ◽  
Beatriz García ◽  
Luis J. Andrés ◽  
Mª Fe Menéndez ◽  
...  

Abstract Background The emergence and expansion of antibiotic resistance makes it necessary to have alternative anti-infective agents, among which silver nanoparticles (AgNPs) display especially interesting properties. AgNPs carry out their antibacterial action through various molecular mechanisms, and the magnitude of the observed effect is dependent on multiple, not fully understood, aspects, particle shape being one of the most important. In this article, we conduct a study of the antibacterial effect of a new type of AgNP: silver nanorings (AgNRs), and compare it with other alternative types of AgNP synthesized in parallel using the same methodology.Results When they act on planktonic forms, AgNRs produce a smaller effect on the viability of different bacteria than nanoparticles with other structures although their effect on growth is more intense over a longer period. When their action on biofilms is analyzed, AgNRs show a greater concentration-dependent effect. In both cases it was observed that the effect on inhibition depends on the microbial species, but not its Gram positive or negative nature. Growth patterns in silver-resistant Salmonella strains suggest that AgNRs work through different mechanisms to other AgNPs. The antibacterial effect is also produced to some extent by the conditioning of culture media or water by contact with AgNPs but, at least over short periods of time, this is not due to the release of Ag ions.Conclusions AgNRs constitute a new type of AgNP, whose antibacterial properties depend on their shape, and is capable of acting efficiently on both planktonic bacteria and biofilms.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Lydie Ploux ◽  
Mihaela Mateescu ◽  
Karine Anselme ◽  
Krasimir Vasilev

In a previous paper, we proposed new silver nanoparticles (SNPs) based antibacterial coatings able to protect eukaryotic cells from SNPs related toxic effects, while preserving antibacterial efficiency. A SNPs containing n-heptylamine (HA) polymer matrix was deposited by plasma polymerization and coated by a second HA layer. In this paper, we elucidate the antibacterial action of these new coatings. We demonstrated that SNPs-loaded material can be covered by thin HA polymer layer without losing the antibacterial activity to planktonic bacteria living in the near surroundings of the material. SNPs-containing materials also revealed antibacterial effect on adhered bacteria. Adhered bacteria number was significantly reduced compared to pure HA plasma polymer and the physiology of the bacteria was affected. The number of adhered bacteria directly decreased with thickness of the second HA layer. Surprisingly, the quantity of cultivable bacteria harvested by transfer to nutritive agar decreased not only with the presence of SNPs, but also in relation to the covering HA layer thickness, that is, oppositely to the increase in adhered bacteria number. Two hypotheses are proposed for this surprising result (stronger attachment or weaker vitality), which raises the question of the diverse potential ways of action of SNPs entrapped in a polymer matrix.


Author(s):  
Samuel Füchtbauer ◽  
Soraya Mousavi ◽  
Stefan Bereswill ◽  
Markus M. Heimesaat

AbstractAntibiotic resistance is endangering public health globally and gives reason for constant fear of virtually intractable bacterial infections. Given a limitation of novel antibiotic classes brought to market in perspective, it is indispensable to explore novel, antibiotics-independent ways to fight bacterial infections. In consequence, the antibacterial properties of natural compounds have gained increasing attention in pharmacological sciences. We here performed a literature survey regarding the antibacterial effects of capsaicin and its derivatives constituting natural compounds of chili peppers. The studies included revealed that the compounds under investigation exerted i.) both direct and indirect antibacterial properties in vitro depending on the applied concentrations and the bacterial strains under investigation; ii.) synergistic antibacterial effects in combination with defined antibiotics; iii.) resistance-modification via inhibition of bacterial efflux pumps; iv.) attenuation of bacterial virulence factor expression; and v.) dampening of pathogen-induced immunopathological responses. In conclusion, capsaicin and its derivatives comprise promising antimicrobial molecules which could complement or replace antibiotic treatment strategies to fight bacterial infections. However, a solid basis for subsequent clinical trials requires future investigations to explore the underlying molecular mechanisms and in particular pharmaceutical evaluations in animal infection models.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1529
Author(s):  
Yu-Hsuan Chen ◽  
Wei-Hsun Wang ◽  
Sheng-Hui Lin ◽  
Yuan-Ting Yang-Wang ◽  
Sung-Pin Tseng ◽  
...  

Acinetobacter baumannii (A. baumannii) is a common and challenging pathogen of nosocomial infections, due to its ability to survive on inanimate objects, desiccation tolerance, and resistance to disinfectants. In this study, we investigated an antibacterial strategy to combat A. baumannii via the combination of antibiotics and silver protein. This strategy used a functional platform consisting of silver nanoparticles (AgNPs) resurrected from silver-based calcium thiophosphate (SSCP) through casein and arginine. Then, the silver protein was combined with tigecycline, the first drug in glycylcycline antibiotic, to synergistically inhibit the viability of A. baumannii. The synergistic antibacterial activity was confirmed by the 96-well checkerboard method to determine their minimum inhibitory concentrations (MIC) and calculated for the combination index (CI). The MIC of the combination of silver protein and tigecycline (0.31 mg/mL, 0.16 µg/mL) was significantly lower than that of the individual MIC, and the CI was 0.59, which indicates a synergistic effect. Consequently, we integrated the detailed synergistic antibacterial properties when silver protein was combined with tigecycline. The result could make for a promising approach for the treatment of A. baumannii.


Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3838
Author(s):  
Hazem Idriss ◽  
Roman Elashnikov ◽  
Silvie Rimpelová ◽  
Barbora Vokatá ◽  
Petr Haušild ◽  
...  

The usage of three-dimensional (3D) printed materials in many bioapplications has been one of the fastest-growing sectors in the nanobiomaterial industry in the last couple of years. In this work, we present a chemical approach for grafting silver nanoparticles (AgNPs) into a resin matrix, which is convenient for 3D printing. In this way, the samples can be prepared and are able to release silver ions (Ag+) with excellent antibacterial effect against bacterial strains of E. coli and S. epidermidis. By the proposed process, the AgNPs are perfectly mixed and involved in the polymerization process and their distribution in the matrix is homogenous. It was also demonstrated that this approach does not affect the printing resolution and the resin is therefore suitable for the construction of microstructures enabling controlled silver ion release and antifouling properties. At the same time the physical properties of the material, such as viscosity and elasticity modulus are preserved. The described approach can be used for the fabrication of facile, low-cost 3D printed resin with antifouling-antibacterial properties with the possibility to control the release of Ag+ through microstructuring.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Hafeezullah Memon ◽  
Hua Wang ◽  
Sohail Yasin ◽  
Adeel Halepoto

This study was conducted by analyzing the effect of surface treatment on wool using varying percentages of protease (3%, 6%, and 9%) with incorporating silver nanoparticles and by varying pH (i.e., pH = 4 and pH = 7). The comparison of fiber surface morphology and the FTIR analysis was done to characterize the nanocoating. The results showed that the antistatic and antibacterial effect on the samples treated at 3% protease and 6% protease were better than the samples treated at 9% protease. Correspondingly, the samples treated at pH 4 had better antistatic and antibacterial properties than those treated at pH 7. Sulfur compounds play a key role in interaction and absorption of silver nanoparticles.


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