Surface Immobilization of Antibacterial Quorum Sensing Inhibitors by Photochemical Activation

Infection of implanted medical devices is one of the major causes of nosocomial infections. A significant proportion of the devices become colonized by bacterial biofilms, thus resulting in high morbidity and risk of mortality. This study focuses on the non-specific covalent attachment of potent quorum sensing (QS) and biofilm inhibiting compounds, furanones (FUs) and dihydropyrrol-2-ones (DHPs), onto glass surfaces by azide/nitrene chemistry. The attachment of FUs and DHPs was confirmed by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. The modified surfaces were then assessed for their antibacterial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa using confocal laser scanning microscopy (CLSM). Both FU and DHP coated surfaces were able to significantly reduce bacterial adhesion (p<0.001) with p-bromophenyl substituted DHP giving maximum reductions of up to 93% and 71% against S. aureus and P. aeruginosa, respectively. Therefore, photoimmobilization of QS inhibitors is an effective technique to produce novel antibacterial biomaterial surfaces.