Polychromatic LED therapy in burn heating of non-diabetic and diabetic rats

Objective: We determined the effect of polychromatic light-emitting diodes (LED) in burn healing of nondiabetic and streptozotocin-induced diabetic rats. Background Data: LEDs were used as the light source for phototherapy. Materials and Methods: The polychromatic LED is a cluster of 25 diodes emitting photons at wavelengths of 510-543, 594-599, 626-639, 640-670, and 842-879 nm with 272-mW output power. Age-matched, male Sprague-Dawley rats (n = 30) were used. Streptozotocin (70 mg/kg) was used for diabetes induction. Rat weight, hyperglycemia, and glycosuria were monitored for the first 3 days and weekly thereafter. Rats were anesthetized and shaved after 1 week of diabetes. Burn areas of 1.5 +/- .03 cm(2) were created using a metal rod pre-heated up to 600degreesC that was applied for 2 sec. Diabetic and non-diabetic rats were randomized into the following treatment groups: control, 5, 10, 20, and 30 J/cm(2). Light treatment commenced after burn infliction and was repeated three times per week. Burn areas were measured daily. Results: Burn healing was impaired significantly during diabetes by -46.17%. Polychromatic LED treatment using 5, 10, 20, and 30 J/cm(2) incident doses influenced healing by 6.85%, 4.93%, -4.18%, and - 5.42% in the non-diabetic rats; and 73.87%, 76.77%, 60.92%, and 48.77% in the diabetic rats, relative to their controls, respectively. Conclusion: The effect of polychromatic LED in non-diabetic rats was insignificant; however, it simulated the trend of stimulation and inhibition seen using low-level lasers. Significant stimulation observed in the diabetic rats demonstrated the usefulness of polychromatic LED in diabetic burn healing.