Antimicrobial Peptide-Conjugated Graphene Coatings for Prevention and Treatment of Bacterial Infections

Graphene, a two-dimensional hexagonal lattice of carbon atoms, displays remarkable physicochemical properties. In contrast to classical chemical exfoliation, chemical vapour deposition (CVD) technology has enabled the production of continuous transparent graphene. CVD graphene coatings on biomedical devices such as contact lenses (CLs) offer several advantages, such as shielding from electromagnetic wave interference and dehydration protection. However, its protective effect against bacteria adhesion remains unexplored. In this study, we designed a series of antimicrobial peptide (AMP)-modified CVD graphene coating on polydimethylsiloxane (PDMS), a biocompatible CLs material. AMPs were successfully conjugated on CVD graphene coating, with negligible impact on the light transmittance. The resultant coating displayed contact angles of less than 50° and protein deposition of less than 9.4 µg cm^-2, indicating transparency, wettability, and protein deposition suitable for biomedical devices. AMPs conjugation on the graphene surface prevented biofilm formation by Pseudomonas aeruginosa (P. aeruginosa), as evidenced by lower colony counts and bacterial metabolic activity. The antimicrobial activity and biocompatibility of the coatings were further demonstrated using ex vivo porcine skins and in vivo rabbit eyes respectively. Overall, this study highlights the potential of AMP-modified CVD graphene coating to minimize bacterial infection and prevent biofilm formation.