Treatment of infected wounds by using antimicrobial blue light phototherapy

Abstract

We aimed to investigate the effects of blue light LED in treating infected wounds. Thirty male mice were divided into G1 (control) and G2 (treated). Two circular excisional skin wounds on the animal's back were made. Infection was created in right wounds 24 hrs. PW by inoculating 0.2 mL Pseudomonas aeruginosa bacterial suspension at dose 2*108 CFU/mL. Left wounds did not inoculate and were left untreated under the same animal control. Infected wounds in G1 were not treated; in G2, they were treated with blue light LED 420 nm 30 J/cm2, single dose/day, for seven successive days. Healing was assessed by measuring the size of the wound, wound bacterial count, and histopathological biopsies obtained at 7- and 14-days PI. The size of the infected wounds in G1 become significantly larger 129.35 and 174.66% at 7- and 14-days PI, respectively. The infection in treated wounds of G2 was eradicated, and the size of wounds was significantly reduced 46.38, and 42.66% at 7- and 14-days PI, respectively. Numbers of bacterial colonies in treated wounds of G2, seventh day PI were expressively reduced at the second dilution. Histopathologically, infected wounds of G1 at 7- and 14-days show suppurative exudate, dead liquefied tissue, and dead and live neutrophils. Treated wounds of G2 at seven days PI, display epithelialization of the epidermis and immature granulation tissue. At 14 days PI, shows a well-regenerated epidermis and mature collagen fibers in the dermis. In conclusions blue LED treatment effectively eradicates P. aeruginosa infection and improves healing.

Keywords

• blue light
• phototherapy
• pseudomonas aeruginosa
• antibiotics resistance
• wound