▎ 摘　　要

Background/purpose: Enterococcus faecalis (E. faecalis) is considered a predominant pathogen for persistent periapical infections. Antisense waIR (ASwaIR) RNA was reported to inhibit the biofilm formation and sensitized E. faecalis to calcium hydroxide medication. The aims of this study were to investigate whether the graphene oxide (GO) nanosheets could be used to enhance antibacterial activity of ASwaIR RNA for E. faecalis in periapical periodontitis. Materials and methods: We developed a graphene-based plasmid transformation system by loading antisense waIR plasmid with GO-polyethylenimine (PEI) complexes (GO-PEI-ASwaIR). The particle size distributions and zeta-potential of the GO-PEI-ASwaIR were evaluated. Then, ASwaIR plasmids were labeled with gene encoding enhanced green fluorescent protein (ASwaIR-eGFP). The transformation efficiencies and the bacterial viability of E. faecalis were evaluated by confocal laser scanning microscopy. Quantitative real-time PCR assays were used to investigate the expressions of E. faecalis virulent genes after transformed by GO-PEI-ASwaIR. Also, the antibacterial properties of the GO-PEI-ASwaIR were validated in the rat periapical periodontitis model. Results: We showed that GO-PEI could efficiently deliver the ASwaIR plasmid into E. faecalis cell. GO-PEI-ASwaIR significantly reduced virulent-associated gene expressions. Furthermore, GO-PEI-ASwaIR suppressed biofilm aggregation and improved bactericidal effects using infected canal models in vitro. In four-weeks periapical infective rat models, the GOPEI-ASwa/R strains remarkably reduced the periapical lesion size. Conclusion: Transformation efficiency and antibacterial prosperity of ASwaIR can be marked improved by GO-PEI based delivery system for E. faecalis infections. (C) 2019 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V.