Physicochemical and biological properties of electrodeposited graphene oxide/chitosan films with drug-eluting capacity

In this study, novel graphene oxide/chitosan nanocomposite coatings with long term drug-eluting potential are presented. The coatings are fabricated by the facile and reproducible electrophoretic deposition technique. Analysis of the prepared films shows that the graphene oxide nanosheets are exfoliated in the chitosan matrix. Fourier-transform infrared spectrometry reveals polymer attachment to the carboxylic bonds of graphene oxide, providing a strong interaction and exfoliation of the nanolayers. In vitro viability assay by human osteosarcoma cells (MG-63) demonstrates that the nanocomposite films are highly biocompatible up to 30 wt% graphene oxide, but at higher concentrations a slight cytotoxicity is noticed. Alkaline phosphates enzyme assay also reveals that the presence of graphene oxide nanosheets moderately hampers osteogenesis of the cultured cells. It is shown that vancomycin-loaded nanocomposite coatings gradually release the drug macromolecules for relatively long period of time (up to 4 weeks). The electrodeposited films also exhibit a high bactericidal potential against Gram-positive Staphylococcus aureus. Effects of graphene oxide nanosheets on the physicochemical, biological, antimicrobial and drug-eluting properties of electrodeposited chitosan films are presented and discussed. It is shown that the GO/CS films support the initial attachment, proliferation and growth of osteoblast-like cells.