Comparative analysis of low-level laser therapy (660 nm) on inflammatory biomarker expression during the skin wound-repair process in young and aged rats (original) (raw)
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Lasers in medical science, 2018
We aim to evaluate the action of transcutaneous laser in the initial wound healing process. The use of low-level laser therapy (LLLT) has proven to be effective on inflammatory modulation and wound healing. The trial was performed on five groups of rats, through a dorsal incision. All groups received treatment on auricular artery. Groups 1 and 3 were treated with transcutaneous LLLT over a period of 15 min. Groups 2 and 4 received one and two inactive laser applications (placebo), respectively. Group 5 was the control one. Blood samples were collected 2 h after the last application of LLLT so that cytokine levels could be measured by ELISA. Tissue fragments were harvested for morphometric, histomorphometric, and RT-qPCR analyses. The morphometric analysis revealed a greater decrease in the wounded area in G1 when compared with G2, whereas in G3, the improvement in the area was greater when compared with G4. Finally, the histomorphometric analysis showed that G1 was the group closer ...
A Reproducible Laser-Wounded Skin Equivalent Model to Study the Effects of Aging In Vitro
Rejuvenation Research, 2004
Hypothesis: Skin aging involves both chronological and photoaging processes. The effects of these processes are often overlapping and include changes in both the stratified epithelium and the fibroblast-rich dermis. Wound healing is frequently delayed and results in scarring. A skin equivalent model can be used to study the role of cells and the extracellular matrix in the process of wound healing. Current studies using this model employ a full-thickness wound placed atop a nonwounded dermis to mimic a partialthickness wound. However, a true reproducible partial-thickness wound model has yet to be described. In this study, we investigated whether a laser-wounded skin equivalent would be a useful partial-thickness wound healing model. Methods: Three lasers were compared for the ability to generate a reproducible wound: an erbium-YAG, a highpowered excimer, and a low-powered excimer laser. Reepithelialization ability was tested using newborn and adult skin keratinocytes, adult esophageal keratinocytes, and cdk4overexpressing newborn keratinocytes. Keratinocyte compartmentalization and basement membrane formation were assessed by immunofluorescence. Results: The erbium-YAG and high-powered excimer laser cut reproducible wounds but left the remaining surface either discolored due to thermal damage and/or ragged; keratinocytes were unable to migrate into the wound area. The low-powered excimer laser cut reproducible wounds, leaving the cut surface intact and visibly unaltered; keratinocytes reepithelialized the wound in a collagenase-dependent manner within 3 days; return of compartmentalization and basement membrane occurred within 14 days. Conclusion: The laser-wounded skin equivalent is an adjustable, reproducible partial-thickness wound model where keratinocyte Laser-wounded skin equivalent
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.
Journal of Photochemistry and Photobiology B-biology, 2007
Background: Low intensity laser therapy has been recommended to support the cutaneous repair; however, so far studies do not have evaluated the tissue response following a single laser treatment. This study investigated the effect of a single laser irradiation on the healing of full-thickness skin lesions in rats. Methods: Forty-eight male rats were randomly divided into three groups. One surgical lesion was created on the back of rats using a punch of 8 mm in diameter. One group was not submitted to any treatment after surgery and it was used as control. Two energy doses from an 830-nm near-infrared diode laser were used immediately post-wounding: 1.3 J cm À2 and 3 J cm À2 . The laser intensity 53 mW cm À2 was kept for both groups. Biometrical and histological analyses were accomplished at days 3, 7 and 14 post-wounding. Results: Irradiated lesions presented a more advanced healing process than control group. The dose of 1.3 J cm À2 leaded to better results. Lesions of the group irradiated with 1.3 J cm À2 presented faster lesion contraction showing quicker re-epithelization and reformed connective tissue with more organized collagen fibers. Conclusions: Low-intensity laser therapy may accelerate cutaneous wound healing in a rat model even if a single laser treatment is performed. This finding might broaden current treatment regimens.
Microscopy research and technique, 2016
Burns are injuries caused by direct or indirect contact to chemical, physical, or biological agents. Low-level laser therapy (LLLT) is a promising treatment since it is low-cost, non-invasive, and induces cell proliferation. This study aimed to investigate the effects of LLLT (660 nm) at two different fluences (12.5 J/cm(2) and 25 J/cm(2) ) per point of application on third-degree burns in rats. Thirty rats (Wistar) divided into GC, GL12.5, and GL25 were used in the study, and submitted to burn injury through a soldering iron at 150°C, pressed on their back for 10 s. LLLT was applied immediately, and 2, 4, 6, and 8 days after wound induction. Histological analysis revealed a decreased inflammatory infiltrate in the group treated with 25 J/cm(2) , and intense inflammatory infiltrate in the control group and in the group treated with 12.5 J/cm(2) . The immunostaining of COX-2 was more intense in the control groups and in the group treated with 12.5 J/cm(2) than in the group treated wi...
Journal of Advanced Biotechnology and Experimental Therapeutics, 2024
Chronic wounds pose significant challenges in healthcare due to impaired healing mechanisms. Fibroblast cells play a crucial role in wound healing by orchestrating proliferation and migration. This study aimed to assess fibroblast cells derived from chronic wounds and explore the impact of low-level laser therapy (LLLT) on their growth and migration. Dermal samples from chronic pressure ulcers and diabetic ulcers were obtained from 20 patients at three sites. Fibroblasts from wound base, margins, and adjacent healing skin were isolated and characterized. Proliferation and migration capabilities of these cells were evaluated. LLLT was applied at various energy levels (2.5, 3, 3.5, 4, and 5 J/cm 2) to assess its effect on cell count. Fibroblasts from chronic wounds exhibited slower proliferation and migration rates compared to normal dermal fibroblasts. Notably, LLLT intervention at different energy levels led to a significant increase in cell count, with the most pronounced effect observed at 3 J/cm 2. LLLT at an energy level of 3 J/cm 2 demonstrated a notable enhancement in fibroblast migration. These findings underscore the potential of LLLT as a therapeutic approach for chronic wounds, offering insights into its efficacy in augmenting fibroblast functions crucial for wound healing.
Brazilian Journal of Medical and Biological Research, 2007
We determined the effects of helium-neon (He-Ne) laser irradiation on wound healing dynamics in mice treated with steroidal and nonsteroidal anti-inflammatory agents. Male albino mice, 28-32 g, were randomized into 6 groups of 6 animals each: control (C), He-Ne laser (L), dexamethasone (D), D + L, celecoxib (X), and X + L. D and X were injected im at doses of 5 and 22 mg/kg, respectively, 24 h before the experiment. A 1-cm long surgical wound was made with a scalpel on the abdomens of the mice. Animals from groups L, D + L and X + L were exposed to 4 J (cm 2)-1 day-1 of He-Ne laser for 12 s and were sacrificed on days 1, 2, or 3 after the procedure, when skin samples were taken for histological examination. A significant increase of collagen synthesis was observed in group L compared with C (168 ± 20 vs 63 ± 8 mm 2). The basal cellularity values on day 1 were: C = 763
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
Anti-inflammatory effect of low-intensity laser on the healing of third-degree burn wounds in rats
Lasers in Medical Science, 2012
Third-degree burn wounds are considered severe injuries because they destroy all the skin layers and may affect subcutaneous tissues, fasciae, muscles, and bones. To favor the healing process of the injured tissues, it is very useful to diminish the occurrence of the inflammatory process. The present study was aimed at comparing the effect of different energetic densities of AlGaInP laser on the inflammatory process and in the healing of third-degree burn wounds in Wistar rats. This study was approved by the Ethics Committee, in which 36 adult male rats were selected and suffered the induction of third-degree burn injury. These rats were divided as follows: group 1-control (treated with silver sulfadiazine), group 2-received energy density of 3 J/cm 2 , and group 3-received energy density of 6 J/cm 2. All animals daily received an occlusive bandage with silver sulfadiazine and 8 % papain. The laser therapy was performed alternatively three times a week. The animals were evaluated on the 3rd, 7th, 14th, and 21st days after the initial lesion and euthanized for the macroscopic, histologic, and morphometric analysis. A higher production of collagen was observed at 7 days and a greater re-epithelialization at 21 days in group 3 (6 J/cm 2). Furthermore, the latter when compared to the other groups presented macroscopically a better aspect of the scar at 21 days with more granulation tissue and fibrosis. We conclude that the AlGaInP laser used in dosages of 3 and 6 J/cm 2 favors the healing of thirddegree burn wounds induced in rats.