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

Nosocomial wound infection with (PA) is a serious complication often responsible for septic mortality of burn patients. High-intensity antimicrobial blue light (aBL) treatment may represent an alternative therapy for PA infections. Antibacterial effects of an light-emitting diode (LED) array (450-460 nm; 300 mW/cm; 15/30 min; 270/540J/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). The aBL reduced the bacterial number (2.51-3.56 log CFU/mL), whereas PRT or CA treatment achieved a 4.64 or 6.60 log CFU/mL reduction in suspension assays. The aBL reduced biofilm formation by 60%-66%. PRT or CA treatment showed reductions by 25% or 13%. In this study, aBL reduced bacterial number in biofilms (1.30-1.64 log CFU), but to a lower extent 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). The 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.