Effect of laser and LED phototherapies on the healing of cutaneous wound on healthy and iron-deficient Wistar rats and their impact on fibroblastic activity during wound healing

Iron deficiency impairs the formation of hemoglobin, red blood cells, as well the transport of oxygen. The wound healing process involves numerous functions, many of which are dependent on the presence of oxygen. Laser has been shown to improve angiogenesis, increases blood supply, cell proliferation and function. We aimed to study the effect of lambda 660 nm laser and lambda 700 nm light-emitting diode (LED) on fibroblastic proliferation on cutaneous wounds on iron-deficient rodents. Induction of iron anemia was carried out by feeding 105 newborn rats with a special iron-free diet. A 1 x 1 cm wound was created on the dorsum of each animal that were randomly distributed into seven groups: I, control anemic; II, anemic no treatment; III, anemic + L; IV, anemic + LED; V, healthy no treatment; VI, healthy + laser; VII, healthy + LED (n = 15 each). Phototherapy was carried out using either a diode laser (lambda 660 nm, 40 mW, 10 J/cm(2)) or a prototype LED device (lambda 700 +/- 20 nm, 15 mW, 10 J/cm(2)). Treatment started immediately after surgery and was repeated at 48-h interval during 7, 14, and 21 days. After animal death, specimens were taken, routinely processed, cut, stained with hematoxylin-eosin, and underwent histological analysis and fibroblast counting. Significant difference between healthy and anemic subjects on regards the number of fibroblast between treatments was seen (p < 0.008, p < 0.001). On healthy animals, significant higher count was seen when laser was used (p < 0.008). Anemic subjects irradiated with LED showed significantly higher count (p < 0.001). It is concluded that the use of LED light caused a significant positive biomodulation of fibroblastic proliferation on anemic animals and laser was more effective on increasing proliferation on non-anemics.