Antimicrobial Peptide-Conjugated Hierarchical Antifouling\nPolymer Brushes for Functionalized Catheter Surfaces

Abstract

Catheter-related\ninfection is a great challenge to modern medicine,\nwhich causes significant economic burden and increases patient morbidity.\nHence, there is a great requirement for functionalized surfaces with\ninherently antibacterial properties and biocompatibility that prevent\nbacterial colonization and attachment of blood cells. Herein, we developed\na strategy for constructing polymer brushes with hierarchical architecture\non polyurethane (PU) via surface-initiated atom-transfer radical polymerization\n(SI-ATRP). Surface-functionalized PU (PU-DMH) was readily prepared,\nwhich comprised of poly­(3-[dimethyl-[2-(2-methylprop-2-enoyloxy)­ethyl]­azaniumyl]­propane-1-sulfonate)\n(PDMAPS) brushes as the lower layer and antimicrobial peptide-conjugated\npoly­(methacrylic acid) (PMAA) brushes as the upper layer. The PU-DMH\nsurface showed excellent bactericidal property against both Gram-positive\nand Gram-negative bacteria and could prevent accumulation of bacterial\ndebris on surfaces. Simultaneously, the PU-DMH samples possessed good\nhemocompatibility and low cytotoxicity. Furthermore, the integrated\nantifouling and bactericidal properties of PU-DMH under hydrodynamic\nconditions were confirmed by an in vitro circulating model. The functionalized\nsurface possessed persistent antifouling and bactericidal performances\nboth under static and hydrodynamic conditions. The microbiological\nand histological results of animal experiments also verified the in\nvivo anti-infection performance. The present work might find promising\nclinical applications for preventing catheter-related infection.