Polychromatic LED in oval full-thickness wound healing in non-diabetic and diabetic rats

Objective: Our goal was to determine the efficacy of polychromatic light-emitting diode (LED) in the enhancement of wound healing in non-diabetic and diabetic rats. Background Data: LEDs are increasingly used as an alternative light source for phototherapy. Methods: A cluster of 25 LED photons at 510-543, 594-599, 626-639, 640-670, and 842-872 nm wavelengths with 272-mW output power was used. Male Sprague-Dawley rats (n=61) were randomly assigned into non-diabetic and diabetic groups and into light treatment groups, that is, control, 5, 10, 20, and 30 J/cm(2). Streptozotocin was used for diabetes induction. Wounds were created using a scalpel after 1 week of diabetes. Light treatment was performed three times per week, which commenced after wounding. Wounds were measured daily and plotted in time, and the trendline was fitted to obtain slope values. Relative wound healing percentage was computed as follows: RWH%=[(Slope treated-Slope control)/(Slope control)] x 100. The t-test (alpha=0.05) was used for analysis. Results: The RWH% in the non-diabetic rats was insignificant (p>0.05) at 5, 10, 20, and 30 J/cm(2) treatments, giving 4.3 +/- 1.97%, 5.4 +/- 1.94%, 4.5 +/- 1.96%, and 1.2 +/- 2.03%, respectively. The healing of diabetic rats was significantly impaired by -11.7 +/- 3.25% (p=0.02), which was mitigated by 5 J/cm(2) treatment (2.4 +/- 3.02%, p=0.40) and 10 J/cm(2) treatment (-5.5 +/- 3.28%, p=0.11). Diabetic wound healing using 20 J/cm(2) (-8.7 +/- 3.39%, p=0.03) and 30 J/cm(2) (-10.90 +/- 1.97%, p=0.01) affected significant inhibition. Conclusion: The effect of polychromatic LED therapy in oval full-thickness wound-healing in the diabetic model with the use of 5 and 10 J/cm(2) is promising. Further studies to determine optimum dosimetry and efficacy of LEDs are recommended.