Glutathione-Stabilized Silver Nanoparticles: Antibacterial Activity against Periodontal Bacteria, and Cytotoxicity and Inflammatory Response in Oral Cells.

Irene Zorraquín-Peña,Dolores González De Llano,M Victoria Moreno-Arribas,Begoña Bartolomé,Carolina Cueva

doi:10.3390/biomedicines8100375

Abstract

Silver nanoparticles (AgNPs) have been proposed as new alternatives to limit bacterial dental plaque because of their antimicrobial activity. Novel glutathione-stabilized silver nanoparticles (GSH-AgNPs) have proven powerful antibacterial properties in food manufacturing processes. Therefore, this study aimed to evaluate the potentiality of GSH-AgNPs for the prevention/treatment of oral infectious diseases. First, the antimicrobial activity of GSH-AgNPs against three oral pathogens (Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus mutans) was evaluated. Results demonstrated the efficiency of GSH-AgNPs in inhibiting the growth of all bacteria, especially S. mutans (IC50 = 23.64 μg/mL, Ag concentration). Second, GSH-AgNPs were assayed for their cytotoxicity (i.e., cell viability) toward a human gingival fibroblast cell line (HGF-1), as an oral epithelial model. Results indicated no toxic effects of GSH-AgNPs at low concentrations (≤6.16 µg/mL, Ag concentration). Higher concentrations resulted in losing cell viability, which followed the Ag accumulation in cells. Finally, the inflammatory response in the HGF-1 cells after their exposure to GSH-AgNPs was measured as the production of immune markers (interleukins 6 and 8 (IL-6 and IL-8) and tumor necrosis factor-alpha (TNF-α)). GSH-AgNPs activates the inflammatory response in human gingival fibroblasts, increasing the production of cytokines. These findings provide new insights for the use of GSH-AgNPs in dental care and encourage further studies for their application.

Highlights

The oral environment is a complex ecosystem comprising different microenvironments that inhabit a variety of microorganisms such as Gemella, Granulicatella, Streptococcus, and Veillonella [1]
The antimicrobial capacity of AgNPs stabilized with the biocompatible tripeptide glutathione on representative periodontal bacteria was demonstrated for the first time
When conducting the cytotoxicity tests of GSH-AgNPs in HGF-1 cells, low nanoparticle concentrations (6.16 μg/mL) did not have a significant cytotoxic effect, since cell viability remained higher than 90% while the loss of viability was over 40% at the Ag concentration of 24.63 μg/mL

Summary

Introduction

The oral environment is a complex ecosystem comprising different microenvironments that inhabit a variety of microorganisms such as Gemella, Granulicatella, Streptococcus, and Veillonella [1]. Diet and the environment influence the microbiota, it is assumed they have a minimal effect on oral bacteria, contrary to what happens with gut bacteria [2]. This form of survival implies greater protection against external agents and tensions by limiting the penetration of antimicrobial agents and by providing mechanical resistance to shear generated by saliva flow [3]. Some of these bacteria are the main etiological agents of caries and periodontal diseases, being among the most prevalent diseases in humans [4,5]. The first predominates the facultative anaerobes such as Streptococcus mutans, Streptococcus

Objectives

Methods

Results

Conclusion