Photobiostimulation effect on diabetic wound at different power density of near infrared laser

• The effects were dose-dependent based on power density in healing process.
• The results showed that the laser treated groups were accelerated contraction of wound.
• In histological evidence, laser treated group shows beneficial effect.
• Low power density promotes healing process.
• High power density showed an inhibitory effect in wound healing.

The photobiostimulation effects of near infrared 808 nm diode laser irradiance on diabetic wound were investigated. 120 rats were induced with diabetes by streptozotocin injection. Full thickness punch wounds of 6 mm diameter were created on the dorsal part of the rats. All rats were randomly distributed into four groups; one group served as control group, whereas three groups were stimulated daily with unchanged energy density dose of 5 J/cm2 with different power density, which were 0.1 W/cm2, 0.2 W/cm2 and 0.3 W/cm2 with different exposure duration of 50 s, 25 s and 17 s, respectively. Ten rats from each group were sacrificed on day 3, 6 and 9, respectively. Skin tissues were removed for histological purpose. The contraction of wound was found optimized after exposure with 0.1 W/cm2. Based on the histological evidence, laser therapy has shown able to promote wound repair through enhanced epithelialization and collagen fiber synthesis. Generally, irradiated groups were advanced in terms of healing than non-irradiated group.