Smart Wearable Patches Using Light‐Controlled Activation and Delivery of Photoswitchable Antimicrobial Peptides

Abstract

A novel strategy to treat Staphylococcus aureus (S. aureus) skin infections is presented, where UV light is used to facilitate concomitant light‐controlled activation and delivery of an antimicrobial therapeutic agent. Specifically, a new photoswitchable gramicidin S analogue was immobilized onto a polymeric wearable patch via a photocleavable linker that undergoes photolysis at the same wavelength of light required for activation of the peptide. Unlike toxic gramicidin S, the liberated active photoswitchable peptide exhibits antimicrobial activity against S. aureus while being ostensibly non‐haemolytic to red blood cells. Moreover, irradiation with visible light switches off the antimicrobial properties of the peptide within seconds, presenting an ideal strategy to regulate antibiotic activity for localized bacterial infections with the potential to mitigate resistance.

A New Gramicidin S Analogue with Potent Antibacterial Activity and Negligible Hemolytic Toxicity

“…The hemolytic activity of these peptides against mammalian red blood cells was determined, with 1 and 2 exhibiting HC 50 values of 25.4 and 46.2 μM, respectively, both more cytotoxic than gramicidin S [HC 50 of 60.1 μM (Figure b and Table )]. Each peptide was found to be more hydrophobic than gramicidin S, supporting the well-established notion that an increase in hydrophobicity correlates with increased hemolytic effects .…”