Influence of He-Ne laser therapy on the dynamics of wound healing in mice treated with anti-inflammatory drugs (original) (raw)
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European Journal of Plastic Surgery, 1995
Helium-neon laser irradiation was applied to the denuded dermis and full-thickness open wounds on rabbit skin and cell cultures of human skin fibroblasts to investigate its effects on the wound healing process. To determine the effects of He-Ne laser radiation on epithelialization rate, 3x3 cm denuded dermis areas on the flank of 16 rabbits were irradiated daily until complete epithelialization occurred. For histopathological evaluation biopsies were taken on the first day and on the day on which epithelialization was complete. As a second part of in vivo study, identical full-thickness skin wounds were created bilaterally on the middle flank area of 12 rabbits. He-Ne laser irradiation was applied daily to the wounds until complete healing occurred to determine the effects of the low-energy laser on the contraction of open wounds. The contralateral wounds were left untreated, serving as controls. In a separate in vitro study, the effect of single or multiple applications of He-Ne laser irradiation on normal human skin fibroblasts in cell cultures was evaluated using growth measurement. The mean epithelialization time was 11_0.63 days for the laser-treated wounds and 12+0.12 days for the control wounds. The difference was not significant. No significant difference was found between the contraction rates of the full-thickness wounds (e.g., on the seventh postoperative day, the average wound area was 70.2__+6.75% of original wound area in the laser-treated group and 66.5_+8.75% in the control group). Histopathologically, epidermal thickening and an increase in dermal vascularity were observed in healed wounds of the laser-treated groups. However, in vitro, this low-energy laser promoted cell growth in human fibroblast cell cultures in 2-and 3-day treated groups (p<0.05).
Effect of Helium-Neon and Infrared Laser Irradiation on Wound Healing In Rabbits
Lasers in surgery …, 1989
We examined the biostimulating effects of helium-neon laser radiation WeNe; 632.8 nm), pulsed infrared laser radiation (IR; 904 nm), and the two combined on skin wound healing in New Zealand white rabbits. Seventy-two rabbits received either 1) no exposure, 2) 1.65 J/cm2 HeNe, 3) 8.25 J/cm2 pulsed IR, or 4) both HeNe and IR together to one of two dorsal full-thickness skin wounds, daily, for 21 days. Wound areas were measured photographically at periodic intervals. Tissue samples were analyzed for tensile strength, and histology was done to measure epidermal thickness and cross-sectional collagen area. Significant differences were found in the tensile strength of all laser-treated groups (both the irradiated and nonirradiated lesion) compared to group 1. No differences were found in the rate of wound healing or collagen area. Epidermal growth was greater in the HeNe-lased area compared to unexposed tissue, but the difference was not significant. Thus, laser irradiation at 632.8 nm and 904 nm alone or in combination increased tensile strength during wound healing and may have released tissue factors into the systemic circulation that increased tensile strength on the opposite side as well. Key words: biostimulation, low-energy densities, skin wounds, tensile strength, trichrome collagen stain, wound area, animal study, rabbit MATERIALS AND METHODS After approval by our Institutional Animal Care and Use Committee, 72 New Zealand white rabbits, 2-3 kg body weight, were randomly divided into four groups of 18: 1) control, 2) continuous-wave HeNe, 3) pulsed IR, and 4) both HeNe and IR. Animals were anesthetized with 0.3-0.5 cc of a solution of ketamine, 100 mg/ml, and acepromazine, 10 mg/ml. The skin was prepared by shaving a 16-cm2 patch across the dorsal midline. The area was scmbbed with a 10% povidone-iodine
Influence of Helium-Neon Laser Photostimulation on Excision Wound Healing in Wistar Rats
OnLine Journal of Biological Sciences, 2007
The importance of laser photostimulation is now accepted generally but the laser light facilitates wound healing and tissue repair remains poorly understood. So we have examined the hypothesis that the laser photo stimulation can enhances the collagen production in excision wounds using excision wound model in Wister rat model. The circular wounds were created on the dorsum of the back of the animals. The animals were divided into two groups. The experimental group (n = 12) wound was treated with 632.8 nm He-Ne laser at a dose of 2.1J cm −2 for five days a week until the complete healing. The control group was sham irradiated. The parameters studied were wound area, period of epithelization and hydroxyproline. Significant increase in the hydroxyproline content (p<0.001) and reduction in the wound size (p<0.001) was observed in study group when compared to controls. The significant epithelization (p<0.001) was noticed. The experimental wounds were, on average, fully healed by the 15th day, whereas the control group healed, on average by 22nd day. Wound contraction together with the hydroxyproline and experimental observations suggested that low intensity Helium-Neon laser photo stimulation facilitates the tissue repair process by accelerating collagen production in chronic wounds.
Effect of helium-neon laser on wound healing
Indian journal of experimental biology, 1999
To estimate the biostimulatory effects of low intensity laser radiation on healing of skin wounds, two linear skin wounds were produced on either side of dorsal midline in rats and immediately sutured. Wounds on the left side were irradiated daily with helium neon laser at 4 Joules/sq.cm for 5 min., while those on right side were not exposed and served as controls. The mean time required for complete closure in control group was 7 days while irradiated test wounds took only 5 days to heal (P < 0.01). The mean breaking strength, as measured by the ability of the wound to resist rupture against force, was found to be significantly increased in the test group. Early epithelization, increased fibroblastic reaction, leucocytic infiltration and neovascularization were seen in the laser irradiated wounds. The results establish the biostimulatory effects of low intensity laser radiation on healing of skin wounds.
Photomedicine and Laser Surgery, 2007
Objective: This study evaluated the action of low-level laser therapy (LLLT) on the modulation of inflammatory reactions during wound healing in comparison with meloxicam. Background Data: LLLT has been recommended for the postoperative period because of its ability to speed healing of wounds. However, data in the literature are in disagreement about its anti-inflammatory action. Methods: Standardized circular wounds were made on the backs of 64 Wistar rats. The animals were divided into four groups according to the selected postoperative therapy: group A-control; group B-administration of meloxicam; and groups C and D-irradiation with red (؍ 685 nm) and infrared (؍ 830 nm) laser energy, respectively. The animals were killed at 12, 36, and 72 h and 7 days after the procedure. Results: Microscopic analysis revealed significant vascular activation of irradiated sites in the first 36 h. Only group B showed decreases in the intensity of polymorphonuclear infiltrates and edema. Group D showed a higher degree of organization and maturation of collagen fibers than the other groups at 72 h. The animals in group C showed the best healing pattern at 7 days. The anti-inflammatory action of meloxicam was confirmed by the results obtained in this research. The quantification of interleukin-1 (IL-1) mRNA by real-time polymerase chain reaction (PCR) did not show any reduction in the inflammatory process in the irradiated groups when compared to the other groups. Conclusions: LLLT improves the quality of histologic repair and is useful during wound healing. However, with the methods used in this study the laser energy did not minimize tissue inflammatory reactions.
Effect of Low Intensity Helium-Neon (He-Ne) Laser Irradiation on Diabetic Wound Healing Dynamics
Photomedicine and laser surgery, 2005
The effect of HeNe laser on the extracellular matrix deposition, chemokine expression and angiogenesis in experimental paracoccidioidomycotic lesions was investigated. At days 7, 8 and 9 postinfection the wound of each animal was treated with a 632.8 nm HeNe laser at a dose of 3 J cm )2 . At day 10 postinfection, the wounds were examined by using histologic and immunohistochemical methods. Results revealed that lasertreated lesions were lesser extensive than untreated ones, and composed mainly by macrophages and lymphocytes. High IL-1b expression was shown in the untreated group whereas in lasertreated animals the expression was scarce. On the other hand, the expression of CXCL-10 was found to be reduced in untreated animals and quite intensive and well distributed in the lasertreated ones. Also, untreated lesions presented vascular endothelial growth factor (VEGF) in a small area near the center of the lesion and high immunoreactivity for hypoxia-inducible factor-1 (HIF-1), whereas laser-treated lesions expressed VEGF surrounding blood vessels and little immunoreactivity for HIF-1. Laser-treated lesions presented much more reticular fibers and collagen deposition when compared with the untreated lesion. Our results show that laser was efficient in minimizing the local effects observed in paracoccidioidomycosis and can be an efficient tool in the treatment of this infection, accelerating the healing process.
Journal of Photochemistry and Photobiology B: Biology, 2007
There are evidences that low-intensity red laser radiation is capable to accelerate wound healing. Nowadays, this therapy has been 14 gradually introduced in clinical practice although mechanisms underlying laser effects are poorly understood. To better understand 15 the photobiological effects of laser radiation, this study investigated by electron microscopy, immunohistochemistry and autoradiogra-16 phy the morphological and functional features of irradiated and none irradiated injured mice skin. Full-thickness skin lesions were cre-17 ated on the back of mice and irradiated on days 1, 5, 8, 12, and 15 post-wounding with a He-Ne laser (k = 632.8 nm), dose 1 J/cm 2 , 18 exposure time 3 min. Non-irradiated lesions were used as a control. The mice were inoculated with 3 H-proline and sacrificed one hour 19 after on the 8th, 15th and 22nd days to histological and radioautographical analysis. The irradiated-lesions showed a faster reepithel-20 ization compared with control lesions. The irradiated dermis contained a higher number of activated fibroblasts compared to control 21 group and, most of them showed several cytoplasmic collagen-containing phagosomes. In irradiated-lesions, smooth muscle a-actin posi-22 tive cells predominated, which correspond to a higher number of myofibroblasts observed in the electron microscope. Moreover, laser 23 radiation reduced the local inflammation and appears to influence the organization of collagen fibrils in the repairing areas. Quantitative 24 autoradiography showed that the incorporation of 3 H-proline was significantly higher in irradiated-dermis on the 15th day post-wound-25 ing (p < 0.05). These results suggest that laser radiation may accelerate cutaneous wound healing in a murine model. 26
Acta Cirurgica Brasileira, 2015
To evaluate wound healing in rats by using low-level laser therapy (LLLT) associated with hydrocolloid occlusive dressing. METHODS: Forty male, adult, Wistar rats were used, distributed into four groups: LG (received 2 J/cm² of laser therapy); HG (treated with hydrocolloid); LHG (treated with 2 J/cm² of laser therapy and hydrocolloid); and the CG (treated with 1 mL of 0.9% saline). The wound was evaluated at predetermined periods 3rd and 7th days, considering the macroscopic and histological parameters (inflammatory cells, capillary neoformation, fibroblasts, collagen formation and reepithelialization). RESULTS: The LG group at seven days showed increased collagen formation, the LHG group at 3 days showed mild collagen formation. The HG group and the CG at 7 days showed complete reepithelialization. CONCLUSION: Low-level laser therapy as well as the hydrocolloid dressing have favored the wound-healing process in rats.
Lasers in Medical Science, 2013
This study aims to investigate the effect of different energy densities provided by low-level laser therapy (LLLT) on the morphology of scar tissue and the oxidative response in the healing of secondary intention skin wounds in rats. Twenty-four male adult Wistar rats were used. Skin wounds were made on the backs of the animals, which were randomized into three groups of eight animals each as follows, 0.9% saline (control); laser GaAsAl 30 J/cm 2 (L30); laser GaAsAl 90 J/cm 2 (L90). The experiment lasted 21 days. Every 7 days, the wound contraction index (WCI) was calculated and tissue from different wounds was removed to assess the proportion of cells and blood vessels, collagen maturation index (CMI), thiobarbituric acid reactive substance (TBARS) levels and catalase activity (CAT). On the 7th and 14th days, the WCI and the proportion of cells were significantly higher in groups L30 and L90 compared to the control (p<0.05). At all the time points analyzed, there was a greater proportion of blood vessels and a higher CMI in group L90 compared to the other groups (p<0.05). On the 7th and 14th days, lower TBARS levels and increased CAT activity were found in the L90 group compared to the control (p<0.05). On the 7th day, a moderately negative correlation was found between TBARS levels and WCI, CMI and CAT in all the groups. LLLT may modulate the oxidative status of wounded tissue, constituting a possible mechanism through which the LLLT exerts its effects in the initial phases of tissue repair.
The effects of topical tripeptide copper complex and helium-neon laser on wound healing in rabbits
Veterinary Dermatology, 2007
The aim of this study was to compare the clinical and histopathological effects of tripeptide copper complex (TCC) and two different doses of laser application (heliumneon laser, 1 and 3 J cm-2) on wound healing with untreated control wounds. Experimental wounds were created on a total of 24 New Zealand white rabbits and topical TCC or laser was applied for 28 days. The wounds were observed daily, and planimetry was performed on days 7, 14, 21 and 28 to measure the unhealed wound area and percentage of total wound healing. Biopsies were taken weekly to evaluate the inflammatory response and the level of neovascularization. The median time for the first observable granulation tissue was shorter (P < 0.05) in the low and high dose laser groups than in the control group (3 and 2.66 vs. 4.5 days), but was not different between the TCC and control groups (4.16 vs. 4.5 days). Filling of the open wound to skin level with granulation tissue was faster (P < 0.05) in the TCC and high dose laser groups than in the control group (14 and 16 vs. 25 days), but was not different between the low dose laser and control groups (23 vs. 25 days). The average time for healing was shorter (P < 0.05) in the TCC and high dose laser groups (29.8 and 30.2 vs. 34.6 days), but was not different between the low dose laser and control groups (33.8 vs. 34.6 days). Histopathologically, wound healing was characterized by a decrease in the neutrophil counts and an increase in neovascularization. The TCC and high dose laser groups had greater neutrophil and vessel counts than in the control group, suggesting a more beneficial effect for wound healing.