Antimicrobial Photodynamic Therapy and Photodynamic Inactivation, or Killing Bugs with Dyes and Light—A Symposium-in-Print


  • Michael R. Hamblin

    1. Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA
    2. Department of Dermatology, Harvard Medical School, Boston, MA
    3. Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA
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In antimicrobial photodynamic therapy, the photosensitizer (PS) in its ground singlet state absorbs light to give the excited singlet state that can transition to the long-lived triplet state. This PS triplet may undergo energy transfer (Type 2) or electron transfer (Type 1) to oxygen to form reactive oxygen species (singlet oxygen and/or hydroxyl radicals) that can kill both Gram-positive and Gram-negative bacteria and fungi. Infections in animal models can also be treated.