Surface-immobilised antimicrobial peptoids

Abstract

Surface modification techniques that create surfaces capable of killing adherent bacteria are promising solutions to infections associated with implantable medical devices. Antimicrobial (AM) peptoid oligomers (ampetoids) that were designed to mimic helical AM peptides were synthesised with a peptoid spacer chain to allow mobility and an adhesive peptide moiety for easy and robust immobilisation onto substrata. TiO₂ substrata were modified with the ampetoids and subsequently backfilled with an antifouling (AF) polypeptoid polymer in order to create polymer surface coatings composed of both AM (active) and AF (passive) peptoid functionalities. Confocal microscopy images showed that the membranes of adherent E. coli cells were damaged after 2-h exposure to the modified substrata, suggesting that ampetoids retain AM properties even when immobilised on substrata.

Keywords:

• ampetoids
• antibacterial
• antimicrobial
• polypeptoid
• antifouling

Acknowledgements

This research was supported by NIH grants R37 DE014193 (PBM), R01 AI072666 and R01 EB003806 (AEB). XPS surface analysis was performed at KeckII/NUANCE, and confocal microscopy was performed at the Biological Imaging Facility at Northwestern University.