Two-Dimensional Materials/Biopolymer-Based\nAntimicrobial\nCoatings to Thwart Biofilm Formation on Medical Implants

Infections associated with medical implants due to bacterial\nadhesion\nand biofilm formation are a serious problem, leading to acute health\nrisks to patients by compromising their immune system. Therefore,\nsuppressing biofilm formation on biomedical implants is a challenging\ntask, especially for overcoming the drug resistance of bacterial biofilms.\nHerein, a synergistic efficient surface coating method was developed\nto inhibit biofilm formation on a model medical implant by combining\nthe antimicrobial property of trimethyl chitosan (TMC) with either\n2D material graphene oxide (GO) or black phosphorus (BP) sheets using\nlayer-by-layer (LbL) self-assembly. The multilayer coatings of TMC/GO\nand TMC/BP were optimized on the glass surface (a model implant) and\ncharacterized by using spectroscopic and microscopy techniques. Next,\nwe investigated the antibiofilm formation properties of the TMC/GO\nand TMC/BP coatings on glass surfaces against both Gram-negative, Escherichia coli (E. coli), and Gram-positive, Bacillus subtilis (<i>B. subtilis</i>), bacteria. The antibiofilm formation\nwas studied using crystal violet (CV) and live/dead assays. Both the\nlive/dead and the CV assays confirmed that the TMC/2D material (2DM)-coated\nsurfaces prevented biofilm formation much more effectively compared\nto the uncoated surfaces. Scanning electron microscopy analyses revealed\nthat the bacteria were affected physically by incubating with TMC/2DM-coated\nsurfaces due to membrane perturbation, thereby preventing cell attachment\nand biofilm formation. Further, BP composite coatings (TMC/BP) showed\na much better ability to thwart biofilm formation than GO composite\ncoatings (TMC/GO). Also, multilayer coatings showed superior cytocompatibility\nwith human foreskin fibroblast (HFF). Our results demonstrate that\nthe developed coatings TMC/2DMs could be potential candidates for\nthwarting biofilm formation on medical implants.