Photomed Laser Surg. 2010 Aug;28(4):547-52.
Effect of LED phototherapy of three distinct wavelengths on fibroblasts on wound healing: a histological study in a rodent model.
de Sousa AP, Santos JN, Dos Reis JA Jr, Ramos TA, de Souza J, Cangussú MC, Pinheiro AL.
Laser Center, School of Dentistry, Federal University of Bahia, Salvador, Bahia, Brazil.
AIM: The aim of the present investigation was to evaluate histologically fibroblastic proliferation on dorsal cutaneous wounds in a rodent model treated or not with light-emitting diodes (LEDs) of three wavelengths.
BACKGROUND: Fibroblasts secrete substances essential for wound healing. There are few reports of LED phototherapy on fibroblast proliferation, mainly in vivo.
ANIMALS AND METHODS: Following approval by the Animal Experimentation Committee of the School of Dentistry of the Federal University of Bahia, we obtained 16 young adult male Wistar rats weighing between 200 and 250 g. Under general anesthesia, one excisional wound was created on the dorsum of each animal; they were then randomly distributed into four groups of four animals each: G0, untreated control; G1, red LED (700 +/- 20 nm, 15 mW, 10 J/cm(2)); G2, green LED (530 +/- 20 nm, 8 mW, 10 J/cm(2)); and G3, blue LED (460 +/- 20 nm, 22 mW, 10 J/cm(2)). The irradiation started immediately after surgery and was repeated every other day for 7 days. Animals were killed 8 days after surgery. The specimens were removed, routinely processed to wax, cut, and stained with hematoxylin/eosin (HE). Fibroblasts were scored by measuring the percentage of these cells occupying the area corresponding to wound healing on stained sections.
RESULTS: The quantitative results showed that red LED (700 +/- 20 nm) and green LED (530 +/- 20 nm) showed a significant increase in fibroblast numbers (p < 0.01 and p = 0.02) when compared with the control group.
CONCLUSION: The use of green and red LED light is effective in increasing fibroblastic proliferation on rodents.
Biofizika. 2008 Sep-Oct;53(5):894-901.
A study of the effect of low-intensity laser radiation of the blue, green, and red spectral regions on the healing of experimental skin wounds in rats
[Article in Russian]
Machneva TV, Protopopov DM, Vladimirov IuA, Osipov AN.
The effect of low-intensity laser radiation of the blue (441.2 nm), green (532 nm), and red (632.8 nm) spectral regions on the healing of experimental skin wounds in rats has been studied. The effect of the traditionally applied laser radiation in the red region has been compared with the effect of laser radiation in the other spectral regions, assuming that, upon irradiation of wounds by lasers emitting in the blue and green regions, a similar effect can be achieved at lower doses. The following parameters characterizing the healing of experimental wounds were used: the functional activity of phagocytes of wound exudates, which was determined by luminol-dependent chemiluminescence, and their number; the antioxidant activity of wound exudates; and the rate of healing, which was determined as a change in the wound area. It was shown that irradiation with laser accelerated the healing of wounds in all cases. The exposure to laser radiations in the red (1.5 J/cm), blue, and green (0.75 J/cm2) spectral regions shortened the time of wound healing from 22 to 17 and 19 days, respectively. The functional activity of leukocytes after the exposure increased on day 5 after the infliction of the wound, whereas in the control it decreased. The superoxide dismutase activity increased in all experimental groups by day 5 after the operation. A maximum increase in the superoxide dismutase activity occurred after the exposure to laser radiation in the red region at a dose of 1.5 J/cm and in the blue and green spectral regions at a dose of 0.75 J/cm2.