Decorating Nanostructured Surfaces with Antimicrobial Peptides to Efficiently Fight Bacteria

With conventional antibiotic therapies being increasingly ineffective, bacterial infections with subsequent biofilm formation represent a global threat to human health. Here, an active and a passive strategy based on polymeric micelles were combined to fight bacterial growth. The passive strategy involved covalent immobilization of polymeric micelles through Michael addition between exposed maleimide and thiol functionalized surfaces. Compared to the bare surface, micelle-decorated surfaces showed reduced adherence and survival of bacteria. To extend this passive defense against bacteria with an active strategy, the immobilized micelles were equipped with the antimicrobial peptide KYE28 (KYEITTIHNLFRKLTHRLFRRNFGYTLR). The peptide interacted nonspecifically with the immobilized micelles where it retained its antimicrobial property. The successful surface decoration with KYE28 was demonstrated by a combination of X-ray photoelectron spectroscopy and quartz crystal microbalance with dissipation monitoring. The initial antimicrobial activity of the nanostructured surfaces against Escherichia coli was found to be increased by the presence of KYE28. The combination of the active and passive strategy represents a straightforward modular approach that can easily be adapted, for example, by exchanging the antimicrobial peptide to optimize potency against challenging bacterial strains, and/or to simultaneously achieve antimicrobial and anti-infection properties.