Intracellular Antimicrobial Photodynamic Therapy: A Novel Technique for Efficient Eradication of Pathogenic Bacteria

Authors

  • Faina Nakonechny,

    1. Department of Chemical Engineering and Biotechnology, Ariel University Center of Samaria, Ariel, Israel
    2. The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
    Search for more papers by this author
  • Michael A. Firer,

    1. Department of Chemical Engineering and Biotechnology, Ariel University Center of Samaria, Ariel, Israel
    Search for more papers by this author
  • Yeshayahu Nitzan,

    1. The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
    Search for more papers by this author
  • Marina Nisnevitch

    Corresponding author
    1. Department of Chemical Engineering and Biotechnology, Ariel University Center of Samaria, Ariel, Israel
      Corresponding author email: marinan@ariel.ac.il (Marina Nisnevitch)
    Search for more papers by this author

Corresponding author email: marinan@ariel.ac.il (Marina Nisnevitch)

Abstract

The increasing resistance of bacteria to antibiotics is a serious problem, caused in part by excessive and improper use of these drugs. One alternative to traditional antibiotic therapy is photodynamic antimicrobial chemotherapy (PACT) which is based on the use of a photosensitizer (PS), activated by illumination with visible light. The poor penetration of visible light through the skin limits the application of PACT to the treatment of skin infections or the use of invasive procedures. To overcome this problem we report the exploitation of light emitted as a result of the chemiluminescent reaction of luminol to excite the PS and we call this process chemiluminescent photodynamic antimicrobial therapy (CPAT). We studied the effect of free and liposome-encapsulated PS (methylene blue or toluidine blue) on bacteria under excitation by either white external light or chemiluminescence emitted by free or liposome-enclosed luminol. PACT showed slightly better performance that CPAT for free and encapsulated PS for both types of bacteria. CPAT resulted in a three log suppression of Staphylococcus aureus and two log suppression of Escherichia coli growth. The use of CPAT may prove to be a novel and more effective form of antimicrobial therapy, particularly for internal infections not easily accessible to traditional PACT.

Ancillary