Tooth-binding graphene quantum dots silver nanoparticles for caries management

Abstract

Aim or Purpose: To develop a tooth-binding graphene quantum dots silver nanoparticles (ALN-GQDs-AgNPs) and evaluate its antibacterial effect on Streptococcus mutans. Materials and Methods: Graphene quantum dots silver nanoparticles (GQDs-AgNPs) was synthesized and conjugated with alendronate (ALN). The synthetic product was characterized by transmission electron microscopy (TEM), Zeta potential, X-ray photoelectron spectroscopy (XPS), Raman spectra and Fourier Transform infrared spectroscopy (FTIR). Binding property was investigated by the amount of ALN-GQDs-AgNPs bound to hydroxyapatite powders which was measured by Inductively Coupled Plasma (ICP) and TEM. Cytotoxicity against human gingival fibroblasts (HGF-1) was examined by CCK-8 assay. Antibacterial effect of ALN-GQDs-AgNPs was measured by inhibition zone against Streptococcus mutans. Results: The TEMimages showed spherical ALN-GQDs-AgNPs was synthesized with diameter 10 nm. The zeta potential of the ALN-GQDs-AgNPs is -53.2. XPS full survey scan showed peaks of O1s, N1s, Ag3d and C1s at 532.3, 399.0, 368.0 and 284.8 eV. The typical feature for GQDs in the Raman spectra were showed on 1340 cm-1 (D band) and 1603 cm-1 (G band). The FTIR spectrum showed the primary and secondary carbonamide band (-N-C=O) of ALN-GQDs-AgNPs. The binding rate of ALN-GQDs-AgNPs was 96% after 60 min. The IC50 of ALN-GQDs-AgNPs were 50.61 ± 15.33 (p < 0.001). The diameter of ALN-GQDs-AgNPs’ inhibition zone is 8.94 ± 0.68 mm. Conclusions: This study developed tooth-binding graphene quantum dots silver nanoparticles which inhibited the growth of a cariogenic bacteria. It can be a potential anti-caries agent.