Antimicrobial and Antibiofilm Properties of Graphene Oxide on <i>Enterococcus faecalis</i>

• Main Authors: Cecilia Martini, Francesca Longo, Raffaella Castagnola, Luca Marigo, Nicola Maria Grande, Massimo Cordaro, Margherita Cacaci, Massimiliano Papi, Valentina Palmieri, Francesca Bugli, Maurizio Sanguinetti
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Series: Antibiotics
• Subjects: antimicrobial properties; biofilm; graphene oxide; <i>Enterococcus faecalis</i>; radicular dentin
• Online Access: https://www.mdpi.com/2079-6382/9/10/692

The aim of this study was to evaluate the antibacterial properties of graphene oxide (GO) against <i>Enterococcus faecalis </i>in vitro conditions and when used to coat dentin surface to prevent <i>E. faecalis</i> adhesion. The ATCC strain of <i>E. faecalis</i> 29212 has been used to perform a viability test. The pellet was suspended in ultrapure water, NaCl, PBS buffer, CaCl₂ and MgCl₂, Luria−Bertani broth solutions. The viability was evaluated by the colony forming unit counting method. Atomic force microscopy images and the measure of surface zeta potential variation were analyzed. Dentin discs were covered with a film of GO (<i>n </i>= 15) or were not treated (<i>n </i>= 15). Bacterial suspension was added to each sample of dentine discs and microbial counts were calculated. Statistically significant differences between two groups were assessed by a two-tailed unpaired <i>t</i>-test. Bacteria cell morphology was investigated with scanning electron microscopy. The highest growth inhibition was obtained in ddH₂O and CaCl₂ solution while, in PBS and NaCl, GO had poor antibacterial efficacy with a growth enhancing effect in the latter. GO on dentin discs demonstrated high antibacterial activity. GO film has demonstrated acceptable adhesion properties to root dentin and a role in the inhibition of bacterial film proliferation and biofilm formation.