Antimicrobial Photodynamic Wound Dressings

Bacterial infections from combat injuries present a significant threat to Warfighters, particularly in the 30 hours immediately after a traumatic injury where there may be a long delay before treatment at a field hospital or clinic. Acute infections stemming from the time of injury can turn into chronic ones, with significant negative impacts on patient recovery. Aside from acute trauma in far-forward situations, patients later face the threat of healthcare-acquired infections (HAIs affect about 5% of all hospital patients in the U.S.). Increasingly HAIs are caused by drug-resistant bacteria that defy standard treatment options. Current combat wound care often includes bandages impregnated with antimicrobial agents, such as nano-silver or antimicrobial polymers, which can reduce antimicrobial growth in wounds, but not fully eliminate it. PhotoCide Protection is developing wound dressings based on light-activated production of reactive oxygen species that rapidly inactivate a broad range of pathogens. This technology, termed antimicrobial photodynamic inactivation, produces highly microbicidal singlet oxygen upon visible light illumination that causes non-specific damage to bacteria and other pathogens. A related application, photodynamic therapy, has been FDA-approved for the treatment of certain cancers. In this project we will evaluate different formulations of antimicrobial coatings on bandages for efficacy in vitro, and in an ex vivo pig skin wound model. PhotoCide has already established methods for the production of antimicrobial photodynamic wound dressings at a TRL of 8-9. For deep tissue wounds, we will also develop a self-contained illumination system that turns on automatically when the bandages are deployed. In this Phase I STTR, we anticipate developing the proof-of-concept for this self-illuminating wound dressing kit to an overall TRL of 3. In Phase II, we expect to develop field-tested prototypes with a TRL of 8-9, and identify opportunities for large scale production.