Ca19Zn2(PO4)14 Nanoparticles: Synthesis, characterization and its effect on the colonization of Streptococcus mutans on tooth surface

Abstract

The main cause of tooth decay is the biofilm formation of Streptococcus mutans. This study aimed to investigate the effect of the zinc oxide nanoparticles (ZnO NPs), hydroxyapatite nanoparticles (Ca10(PO4)6(OH)2) (HAP NPs), zinc oxide/hydroxyapatite nanocomposites (ZnO/HAP NCs), and Zn-substituted hydroxyapatite nanoparticles (Ca19Zn2(PO4)14 NPs) on the growth and biofilm formation, bacterial adherence, and the expression of ftf and gtf genes in Streptococcus mutans. The nanostructures were prepared via simple and fast co-precipitation route. Twelve isolates of Streptococcus mutans collected from children with dental caries referred to the dental clinic of Kashan University of Medical Sciences. All S. mutans isolates were susceptible to Ampicillin. The mean MIC for ZnO NPs, HAP NPs, Ca19Zn2(PO4)14, and ZnO/HAP NCs were 118, 260, 70.6, and 994 µg/mL, respectively. All prepared nanostructures significantly reduced biofilm formation at MIC and sub-MIC concentrations (p < 0.01). In biofilm and cell culture treated with nanoparticles, the expression of ftf and gtfC genes decreased. Results were shown that IC50 for the Ca19Zn2(PO4)14 was 8.5, and for non-toxic concentration, was 0.065 µg/mL. The attachment rate to the denture surface and HGF1 cell line treated with the Ca19Zn2(PO4)14 NPs has decreased. The results showed that the Ca19Zn2(PO4)14 NPs has a better effect than the ZnO/HAP NCs. It can therefore be used as a coating on dental surfaces. Investigation of Ca19Zn2(PO4)14 NPs form for covering dental teeth surface recommended in future study.