Photodynamic therapy of antibiotic-resistant biofilms in a maxillary sinus model

Int Forum Allergy Rhinol. 2013 Jun;3(6):468-73. doi: 10.1002/alr.21134. Epub 2013 Jan 10.

Abstract

Background: Chronic rhinosinusitis (CRS) is one of the most common chronic conditions in the United States. There is a significant subpopulation of CRS patients who remain resistant to cure despite rigorous treatment regimens including surgery, allergy therapy, and prolonged antibiotic therapy. Antimicrobial photodynamic therapy (aPDT) is a noninvasive nonantibiotic broad spectrum antimicrobial treatment. Our previous in vitro studies demonstrated that aPDT reduced CRS polymicrobial planktonic bacteria and fungi by >99.9% after a single treatment. However, prior to human treatment, the effectiveness of aPDT to eradicate polymicrobial biofilms in a maxillary sinus cavity must be demonstrated. The objective of this study was to demonstrate the effectiveness of a noninvasive aPDT treatment of antibiotic resistant biofilms known to cause CRS in a novel anatomically correct maxillary sinus in vitro model using an enhanced photosensitizer solution.

Methods: Antibiotic resistant polymicrobial biofilms of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) were grown in an anatomically correct novel maxillary sinus model and treated with a methylene blue/ethylenediamine tetraacetic acid (EDTA) photosensitizer and 670-nm nonthermal activating light. Cultures of the biofilms were obtained before and after light treatment to determine efficacy of biofilm reduction.

Results: The in vitro maxillary sinus CRS biofilm study demonstrated that aPDT reduced the CRS polymicrobial biofilm by >99.99% after a single treatment.

Conclusion: aPDT can effectively treat CRS polymicrobial antibiotic resistant Pseudomonas aeruginosa and MRSA biofilms in a maxillary sinus cavity model.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Anti-Bacterial Agents / therapeutic use*
  • Biofilms / drug effects*
  • Chronic Disease
  • Edetic Acid / therapeutic use
  • Humans
  • Maxillary Sinus / microbiology*
  • Methicillin-Resistant Staphylococcus aureus / drug effects
  • Methicillin-Resistant Staphylococcus aureus / physiology
  • Methylene Blue / therapeutic use
  • Models, Anatomic
  • Photochemotherapy / methods*
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / physiology
  • Rhinitis / drug therapy*
  • Rhinitis / microbiology
  • Sinusitis / drug therapy*
  • Sinusitis / microbiology
  • Treatment Outcome

Substances

  • Anti-Bacterial Agents
  • Edetic Acid
  • Methylene Blue