The Effect of NIR Light and the Light-Activated Antimicrobial Agent on Wound Pathogenic Biofilms; Implication for Nonpharmacologic Chronic Wound Treatment

Ghada Said Mohammed Omar

    Publikation: Konferencebidrag uden forlag/tidsskriftAbstraktForskning


    Baggrund / Background
    Chronic infected wounds represent a significant cause of morbidity in developed countries and are estimated to affect 1-2 % of the population. In Denmark, 2–3% of the health care budget is used on wound treatment and the socioeconomic problem will keep growing worldwide due to the increase of lifestyle diseases, as diabetes, obesity, and cardiovascular diseases. The presence of bacterial biofilms is considered an important factor responsible for wounds chronicity. Therefore, this study investigates the efficacy of near-infrared (NIR) laser in vitro, in disrupting wound pathogenic biofilms.

    Metoder / Methods
    Biofilms of Staphylococcus aureus and Pseudomonas aeruginosa were grown in a 96-well microtiter plate for 18-22 h. The study included 4 arms: (a) control; (b) 200 µg/mL Indocyanin green (ICG) kept in the dark, (c) NIR laser alone; (d) NIR laser combined with 200 µg/mL. ICG. The biofilms were exposed to different light doses from the 808 nm NIR laser at a fluence rate of 0.3 W/cm2. Crystal violate assay and viable count were used to detect the effect.

    (Foreløbige) resultater / (Preliminary) Results
    A light dose of 90 J/cm2 killed approximately 99.9% of P. aeruginosa bacterial cells encased in biofilms, while a combination of both light and dye resulted in a 99.3% kill. Exposure of Staph. aureus biofilms to ICG in combination with NIR laser light or to the NIR light alone resulted in 99.9% and 99.7% reductions in the number of viable bacteria, respectively.

    Konklusioner / Conclusions
    NIR laser alone was superior to the combination of ICG and NIR light in killing P. aeruginosa biofilms. However the combination of NIR with ICG was more effective in disrupting Staph. aureus biofilms. Thus NIR light laser may be a promising nonpharmacologic treatment method for disrupting biofilms present in chronic wounds.
    Publikationsdato23 sep. 2015
    StatusUdgivet - 23 sep. 2015