Layered defense: antimicrobial peptide-graphene oxide coatings against multidrug-resistant biofilms on medical implants.

Implant-associated infections (IAIs) caused by multidrug-resistant (MDR) pathogens are incredibly challenging to treat due to their strong resistance to conventional antibiotics. Here, we developed efficient biofilm-preventive multilayer coatings against the MDR strain Acinetobacter baumannii (A. baumannii) by leveraging the synergistic antimicrobial activity of the antimicrobial peptide protamine (PR) and graphene oxide (GO) for medical implants. First, the anti-biofilm activity of the PR/GO multilayer coatings was successfully demonstrated against both Gram-negative and Gram-positive bacteria using crystal violet colony counting and live/dead assays, as well as electron microscopy (by observing morphological changes). Moreover, the PR/GO-coated surfaces demonstrated promising anti-biofilm activity against multidrug-resistant A. baumannii. Furthermore, the PR/GO-coated surfaces demonstrated biocompatibility with mammalian cells, indicating the safety of the PR/GO multilayer coatings intended for medical implants.