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

Nosocomial wound infection with (PA) is a serious complication often responsible for the septic mortality of burn patients. High-intensity antimicrobial blue light (aBL) treatment may represent an alternative therapy for PA infections and will be investigated in this study. Antibacterial effects of a light-emitting diode array (450-460 nm; 300 mW/cm; 15/30 min; 270/540 J/cm) against PA were determined by suspension assay, biofilm assay, and a human skin wound model and compared with 15-min topically applied 3% citric acid (CA) and wound irrigation solution (Prontosan; PRT). aBL reduced the bacterial number [2.51-3.56 log colony-forming unit (CFU)/mL], whereas PRT or CA treatment achieved a 4.64 or 6.60 log CFU/mL reduction in suspension assays. aBL reduced biofilm formation by 60-66%. PRT or CA treatment showed reductions by 25% or 13%. Here, aBL reduced bacterial number in biofilms (1.30-1.64 log CFU), but to a lower extend than PRT (2.41 log CFU) or CA (2.48 log CFU). In the wound skin model, aBL (2.21-2.33 log CFU) showed a bacterial reduction of the same magnitude as PRT (2.26 log CFU) and CA (2.30 log CFU). aBL showed a significant antibacterial efficacy against PA and biofilm formation in a short time. However, a clinical application of aBL in wound therapy requires effective active skin cooling and eye protection, which in turn may limit clinical implementation.