Synthesis and Characterization of Fluoridated Silver Nanoparticles and Their Potential as a Non-Staining Anti-Caries Agent

Int J Nanomedicine. 2020 May 6:15:3207-3215. doi: 10.2147/IJN.S243202. eCollection 2020.

Abstract

Objectives: The first objective of this study was to prepare sodium fluoride (NaF) solution with various concentrations of polyethylene glycol-coated silver nanoparticles (PEG-AgNPs). The second objective was to study the antibacterial activity against Streptococcus mutans and the tooth-staining effect of the solution.

Methods: PEG-AgNPs were prepared via the one-step chemical reduction of silver acetate with thiolated polyethylene glycol. The PEG-AgNPs were characterized with ultraviolet-visible spectrometry and transmission electron microscopy. The half maximal inhibitory concentration (IC50) for the PEG-AgNPs against Streptococcus mutans and human gingival fibroblasts (HGF-1) were determined. The staining effect on dentin and enamel for the 2.5% NaF solutions with PEG-AgNPs at 12,800, 6400, 1600, and 400 ppm was investigated using digital spectrophotometry. The IC50 of the fluoridated silver nanoparticles against Streptococcus mutans were measured.

Results: The PEG-AgNPs have an average diameter of 2.56±0.43 nm and showed excellent stability at high ionic strength (2.5% NaF) for 18 months. The IC50 of PEG-AgNPs against Streptococcus mutans was found to be 21.16±1.08 ppm silver, which was half of IC50 against HGF-1 cells (42.36±1.12 ppm), providing a working range to kill bacteria with no harm to human cells. The formulations with different concentrations of PEG-AgNPs showed no significant staining of teeth. Combining PEG-AgNPs with NaF significantly expanded the therapeutic window against Streptococcus mutans by reducing its IC50.

Conclusion: A biocompatible solution of NaF with PEG-AgNPs was developed. Because it has antibacterial activity against Streptococcus mutans and no tooth-staining effect, it can be used as an anti-caries agent.

Keywords: antibacterial; caries; dentin; fluoride; nanoparticles; silver.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Anti-Bacterial Agents / therapeutic use
  • Cariostatic Agents / pharmacology
  • Cariostatic Agents / therapeutic use
  • Dental Caries / drug therapy*
  • Dental Caries / microbiology
  • Fluorides / chemical synthesis*
  • Fluorides / therapeutic use*
  • Gingiva / drug effects
  • Humans
  • Metal Nanoparticles / chemistry*
  • Metal Nanoparticles / ultrastructure
  • Microbial Sensitivity Tests
  • Polyethylene Glycols / chemistry
  • Silver / pharmacology
  • Silver / therapeutic use*
  • Spectrophotometry, Ultraviolet
  • Staining and Labeling*
  • Streptococcus mutans / drug effects

Substances

  • Anti-Bacterial Agents
  • Cariostatic Agents
  • Silver
  • Polyethylene Glycols
  • Fluorides