Antimicrobial and Antibiofilm Effects of Silver-Copper Nanoparticles Obtained by Green Synthesis Against Streptococcus mutans

Cureus. 2024 Apr 16;16(4):e58368. doi: 10.7759/cureus.58368. eCollection 2024 Apr.

Abstract

Introduction: Oral diseases affect billions worldwide, with dental caries being a significant concern. Silver-copper nanoparticles (Ag-Cu NPs) synthesized from pitaya plant extract offer a potential solution due to their antimicrobial properties. This study aimed to evaluate the inhibitory effects of Ag-Cu NPs on Streptococcus mutans (S. mutans), a major contributor to dental caries.

Methodology: Ag-Cu NPs were synthesized using a green chemical method and characterized using a scanning electron microscope (SEM), ultraviolet-visible (U-vis) spectrophotometer, and Fourier Transform Infrared Spectroscopy (FT-IR). The minimum inhibitory concentration (MIC) against S. mutans was determined using the broth microdilution method, while the antibiofilm effect was assessed by the crystal violet method.

Results: The synthesized Ag-Cu NPs demonstrated antimicrobial activity with an MIC of 128 µg/ml, significantly inhibiting S. mutans biofilm formation by up to 94% at a concentration of 256 µg/ml. Characterization studies confirmed the successful synthesis of Ag-Cu NPs with spherical morphology.

Conclusions: These findings highlight the potential of Ag-Cu NPs as a novel approach for combating dental caries by targeting S. mutans biofilms. Further research is warranted to explore their safety and efficacy in clinical settings.

Keywords: antibiofilm assay; antimicrobial effect; copper nanoparticles; silver nanoparticles; dental caries.