Charge Stabilized Silver Nanoparticles Applied as Antibacterial Agents

Abstract

Monodisperse silver nanoparticle sols were synthesized via chemical reduction processes in aqueous environment without using polymeric stabilizing agents or surfactants. The sols obtained using various reducing agents; inorganic cell permeabilizers and organic phenolic compounds; inter alia gallic acid (GA) and tannin (TA) were thoroughly characterized by various physicochemical methods such as TEM, SEM, AFM, DLS and micro-electrophoresis. The antibacterial activity of the sols against two E. coli strains was characterized via the determination of the Minimum Bactericidal Concentration (MBC). All sols exhibited a pronounced bactericidal effect against the standard K12 strain, especially the GA and TA sols showing MBC concentration as low as 1-5 mg L(-1). In the case of the antibiotic resistant strain the highest activity (MBC of 10 mg L(-1)) was observed for the sol synthesized using sodium hypophosphate and sodium tripolyphosphate. Additionally, interactions of silver nanoparticles with bacteria cell were studied using TEM and AFM imaging. It was shown that the silver particles attach to the bacteria surface inducing disintegration, which enables their penetration inside the bacteria. Our measurements confirmed that the surface chemistry of silver nanoparticles can play a decisive role.

Effects of exposure of callus cells of two wheat varieties to silver nanoparticles and silver salt (AgNO3)

“…Tannic acid contains glucose esterified by gallic acid in the central core, and because of this specific structure it has a stabilizing effect on metal nanoparticles (Dadosh 2009;Dutta and Dolui 2011;Sivaraman et al 2009Sivaraman et al , 2010. AgNPs synthesized using tannic acid have unique properties, as presented in our prior studies about its antibacterial activity against selected strains of Escherichia coli and its cytotoxic activity against human cells (Kujda et al 2015;Barbasz et al 2015). It is still not known whether the toxicity to living organisms resulted from AgNPs themselves or associated with the release of silver ions from the particles' surface.…”

How the surface properties affect the nanocytotoxicity of silver? Study of the influence of three types of nanosilver on two wheat varieties

“…Treatment of calli of both wheat cultivars by SBNM did not significantly influence SOD activity. Positively charged AgNPs have been shown to be the most toxic to bacteria and animal cells (Kujda et al 2015;Silva et al 2014). Also our research shows that AgNPs with positive charge (SBATE) are the most toxic to the cells tested.…”

“…The surface properties of AgNPs, such as charge and oxidation state, depend on the physico-chemical characteristics of stabilizing agent (Kujda et al 2015;Silva et al 2014). It has been shown that positively charged AgNPs which are more prone to oxidative dissolution independently of their size exhibit higher toxicity for living organisms (Kittler et al 2010;Silva et al 2014).…”

Application Of Nanotechnology In Agriculture And Food Industry, Its Prospects And Risks

“…Some toxicological studies have reported that the nanomaterials can be cytotoxic [387][388][389][390][391][392], genotoxic [391,[393][394][395][396][397][398][399], bactericidal [400][401][402][403][404], neurotoxic [405][406][407][408][409] and ecotoxic [410][411][412][413][414].…”