High-Intensity Blue Light (450-460 nm) Phototherapy for Pseudomonas aeruginosa-Infected Wounds

Andreas Zoric1, Mahsa Bagheri2, Maria von Kohout3

  • 1Plastic, Reconstructive, and Esthetic Surgery, RKH Hospital Bietigheim-Vaihingen, Bietigheim-Bissingen, Germany.

Insights

High-intensity antimicrobial blue light (aBL) shows promise for treating Pseudomonas aeruginosa wound infections. While effective against biofilms, its clinical use requires further development for skin cooling and eye protection.

Area of Science:

  • Medical Microbiology
  • Photomedicine
  • Wound Care

Background:

  • Nosocomial wound infections caused by Pseudomonas aeruginosa (PA) are a significant cause of mortality in burn patients.
  • Antimicrobial blue light (aBL) presents a potential alternative therapeutic strategy for PA infections.

Purpose of the Study:

  • To evaluate the antibacterial efficacy of high-intensity antimicrobial blue light (aBL) against Pseudomonas aeruginosa (PA) in vitro and in a human skin wound model.
  • To compare the effectiveness of aBL with topical citric acid (CA) and Prontosan® (PRT) wound irrigation solutions.

Main Methods:

  • Antibacterial effects were assessed using suspension assays, biofilm assays, and a human skin wound model with a light-emitting diode (LED) array (450-460 nm).
  • Treatments included aBL (300 mW/cm², 15/30 min), 3% citric acid (CA), and Prontosan® (PRT).
  • Bacterial reduction was quantified using log10 CFU/mL and log10 CFU measurements.

Main Results:

  • aBL reduced PA in suspension (2.51-3.56 log10 CFU/mL), but less effectively than PRT (4.64 log10 CFU/mL) or CA (6.60 log10 CFU/mL).
  • aBL inhibited biofilm formation (60%-66%), outperforming PRT (25%) and CA (13%).
  • In the wound model, aBL demonstrated comparable bacterial reduction (2.21-2.33 log10 CFU) to PRT (2.26 log10 CFU) and CA (2.30 log10 CFU).

Conclusions:

  • aBL exhibits significant antibacterial activity against PA and reduces biofilm formation within a short treatment duration.
  • Clinical implementation of aBL for wound therapy necessitates addressing challenges related to active skin cooling and eye protection.