Graphene Oxide and Reduced Graphene Oxide

Abstract

To present a possible new alternative for wound treatment, this work evaluated the biological safety and therapeutic efficacy of graphene oxide (GO) and reduced graphene oxide (rGO) nanoparticles (NPs). First, the nanostructures were studied in silico and showed to be able to inhibit the production of some pro-inflammatory cytokines and stimulate the production of the anti-inflammatory cytokine IL-10, especially rGO. The results of the morphological and structural characterization of GO NPs synthesized from the Hummers method and reduced by ascorbic acid, were consistent with the literature, confirming their achievement. In the broth microdilution assay, GO and rGO showed antimicrobial activity against the clinical isolate of Streptococcus agalactiae (S. agalactiae) at a minimum inhibitory concentration (MIC) of 625 µg/mL for GO and 312.5 µg/mL for rGO. In addition, the nanostructure of rGO was able to inhibit, in subinhibitory concentration, the formation of S. agalactiae biofilm by up to 77% when compared to the positive control. Both NPs, in all tested concentrations, did not cause hemolysis, and alterations in coagulation in vitro assays. However, in the safety tests, it was evidenced that only the MIC of 312, µg/mL for rGO was biologically safe and presented anti-inflammatory and healing behavior in vitro. In general, the present work confirmed rGO's potential in the treatment of chronic wounds, since in silico showed anti-inflammatory behavior and in vitro showed therapeutic efficacy at low concentrations, prevented biofilm formation, and showed no significant toxic effects.