Wound healing in diabetic rat by 808 NM laser diode

Abstract

Low Level Laser Therapy (LLLT) has been widely used in dermatology field especially diabetic wound healing. However, there is lack of a high power density laser in use for the same treatment. Hence, investigation was carried out to study the effect of high power density diode laser on diabetic wound. 45 mg/kg of Streptozotocin was used to induce diabetes on Sprague Dawley rats. 808 nm laser diode was employed for diabetic treatment. It operated at various doses between 0.11 to 0.51 W/cm2 at interaction times of 30 s, 60 s and 120 s for each session. Six full thickness punch wounds of 6 mm diameter were generated on the dorsal part of the rats. The rats were divided into six groups; one group served as control group, whereas five groups were stimulated daily with constant energy density of 5 J/cm2 corresponding to different power density, between 0.1 to 0.5 W/cm2 with different exposure duration of 50 s, 25 s, 17 s, 12.5 s and 10 s respectively. Wound contraction, tensile strength and histology were examined to well understand wound healing process. The photostimulation effect is responsible to enhance the tensile strength and facilitates collagen production. The wound contraction rate of the laser therapy group was found two times faster compared to that of the control group. The contraction of wound was optimized after exposed to 0.1 W/cm2 with corresponding exposure duration of 50 s. Based on the histological evidence, low level laser therapy has been able to promote wound repair via enhancing the epithelialization and collagen fiber synthesis. Generally, the irradiated groups were more advanced in terms of healing than non-irradiated group. This indicates that the 808 nm laser diode can enhance tensile strength of skin and accelerate the wound healing process.