Low level laser therapy (AlGaInP) applied at 5J/cm2 reduces the proliferation of Staphylococcus aureus MRSA in infected wounds and intact skin of rats* (original) (raw)
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Effects of low intensity laser in in vitro bacterial culture and in vivo infected wounds
Revista do Colégio Brasileiro de Cirurgiões, 2014
Effects of low intensity laser in in vitro bacterial culture and in vivo infected wounds 49 Rev. Col. Bras. Cir. 2014; 41(1): 049-055 ABSTRACT ABSTRACT ABSTRACT ABSTRACT ABSTRACT Objective Objective Objective Objective Objective: to compare the effects of low intensity laser therapy on in vitro bacterial growth and in vivo in infected wounds, and to analyze the effectiveness of the AsGa Laser technology in in vivo wound infections. Methods
Photomedicine and laser surgery, 2011
Aim: We aimed to assess the use of two wavelengths on the healing of infected wounds. Background: Infection is the most significant cause of impaired wound repair or healing. Several therapeutic approaches are used for improving wound healing including the use of different light sources, such as the laser. Some wavelengths yield positive photobiological effects on the healing process. Material and Methods: The backs of 24 young adult male Wistar rats under general anesthesia were shaved and cleaned, and a 1 by 1 cm cutaneous wound was created with a scalpel and left untreated. The wounds were infected with Staphylococcus aureus, and the rats were randomly divided into two sets of four subgroups with three animals in each subgroup: control, red laser light, infrared laser light, and red þ infrared laser light. Laser phototherapy was carried out with a diode [l680 nm/ 790 nm, power (P) ¼ 30 mW/40 mW, continuous wave laser, Ø ¼ 3 mm, power density (P) ¼ 424 and 566 mW/ cm 2 , time ¼ 11.8/8.8 sec, E ¼ 0.35 J] and started immediately after surgery and repeated every other day for 7 d. Laser light was applied on four points around the wounded area (5 J/cm 2 ). The animals were killed either 8 or 15 d after contamination. Specimens were taken, embedded in paraffin, and sectioned and stained for histological analysis. Results: Histological analysis showed that control subjects had a lower amount of blood vessels when compared with irradiated subjects. Irradiated subjects had more advanced resolution of inflammation compared with controls. Irradiated subjects also showed a more intense expression of the collagen matrix. The collagen fibers were mostly mature and well organized in these subjects at the end of the experimental time especially when both wavelengths were used. Conclusion: The results of the present study indicate that laser phototherapy has a positive effect on the healing of infected wounds, particularly with the association of l680 þ l790 nm.
Laser Therapy for Wound Healing: A Review of Current Techniques and Mechanisms of Action
Biosciences Biotechnology Research Asia
Along with conventional medications, different techniques have been used for wound healing such as ultrasound, electric field, magnetic field, pressure relieving beds, cushions, etc. These methods are usually utilized for prevention and healing of pressure wounds. One of these methods with great potential is LASER (Light Amplification by Stimulated Emission of Radiation) therapy. Different parameters can affect the efficiency of laser therapy. Several studies have attempted to develop this technique in different medical applications. This paper aims to provide a review of the LASER techniques for wound healing, sketch their background, determine the biological effects that support the use of LASER sources in the treatment of wounds and as well as the optimal light parameters such as wavelength and dose for wound healing Keywords : Laser, Wound Healing, Mechanism of Action
Low laser therapy (photobiomodulation) on bacteria of pressure ulcers: in vitro studies
Fisioterapia Brasil
The biological effects promoted by low power laser result in faster wound healing. However, wounds are very complex systems from both host and microbial point of view. Since infection is a common cause of delayed wound healing, it is important to understand the effect of low-level laser therapy in bacterial growth. This mini-review summaries the current evidence about effects of low level laser on bacteria vitro studies.Key-words: Low power laser, infected injury, bacteria.
Laboratory methods for evaluating the effect of low level laser therapy (LLLT) in wound healing
African Journal of Biomedical Research, 2006
The basic tenet of laser therapy is that laser radiation has a wavelength dependent capability to alter cellular behaviour in the absence of significant heating. Low intensity radiation can inhibit as well as stimulate cellular activity. Laser therapy typically involves the delivery of 1-4J/cm 2 to treatments sites with lasers having output powers between 10mW and 90mW. There are two major areas of laser therapy research: the laboratory and the clinic. The laboratory presents the least ambiguous results. Here, although unsupported results do appear, the vast majority of published work finds clear evidence that laser irradiation alters cellular processes in a nonthermal, wavelength-dependent manner. Low energy laser irradiation alters t he cellular function by effecting protein synthesis, cell growth and differentiation, cell motility, membrane potential and binding affinities, neurotransmitter release, ATP synthesis and prostaglandin synthesis. Laboratory findings provide scientific rati onale of laser therapy and the effect of laser therapy on cellular processes. This review outlines some of the current methods employed in the laboratory to measure the effect of low level laser therapy (LLLT) on cellular and molecular processes in the cell. This review briefly explains the different structural, cellular and molecular parameters and highlights some of the basic principles and protocols including specialized equipment requirements.
International Wound Journal, 2012
Chronic wounds, including diabetic foot ulcers, pressure ulcers and venous leg ulcers, represent a significant cause of morbidity in developed countries, predominantly in older patients. The aetiology of these wounds is probably multifactorial, but the role of bacteria in their pathogenesis is still unclear. Moreover, the presence of bacterial biofilms has been considered an important factor responsible for wounds chronicity. We aimed to investigate the laser action as a possible biofilm eradicating strategy, in order to attempt an additional treatment to antibiotic therapy to improve wound healing. In this work, the effect of near-infrared (NIR) laser was evaluated on mono and polymicrobial biofilms produced by two pathogenic bacterial strains, Staphylococcus aureus PECHA10 and Pseudomonas aeruginosa PECHA9, both isolated from a chronic venous leg ulcer. Laser effect was assessed by biomass measurement, colony forming unit count and cell viability assay. It was shown that the laser treatment has not affected the biofilms biomass neither the cell viability, although a small disruptive action was observed in the structure of all biofilms tested. A reduction on cell growth was observed in S. aureus and in polymicrobial biofilms. This work represents an initial in vitro approach to study the influence of NIR laser treatment on bacterial biofilms in order to explain its potentially advantageous effects in the healing process of chronic infected wounds. contributed equally to this work.
Lasers in Medical Science, 2013
The aim of the present study was to compare the effectiveness of four different laser wavelengths (660, 810, 980, and 1,064 nm) used for low-level laser therapy (LLLT) on the healing of mucositis in an animal model of wound healing by investigating the expression of platelet-derived growth factor (PDGF), transforming growth factor beta (TGF-β), and blood-derived fibroblast growth factor (bFGF). Thirty-five male Wistar albino rats with a weight of 250-300 g body mass and 5 months old were used in the study. All animals were intraperitoneally injected with 100 mg/kg of 5-fluorouracil (5-FU) on the first day and 65 mg/kg of 5-FU on the third day. The tip of an 18-gauge needle was used in order to develop a superficial scratching on the left cheek pouch mucosa by dragging twice in a linear movement on third and fifth days. After ulcerative mucositis were clinically detected on the animals' left cheek pouch mucosa, the laser therapy was started. Four different laser wavelengths (660 nm, HELBO, Bredent; 810 nm, Fotona XD, Fotona; 980 nm, ARC Fox; and 1,064 nm, Fidelis Plus 3, Fotona) used for LLLT at ED 8 J/cm 2 daily from the first to the fourth days. Oval excisional biopsy was taken from the site of the wound, and the expression of PDGF, TGF-β, and bFGF was evaluated. The obtained data were analyzed by one2-way ANOVA, and then Tukey HSD tests were used for pairwise comparisons among groups (α=0.05). The one-way ANOVA test indicated that expression values of the growth factors, PDGF and bFGF, were significantly affected by irradiation of different wavelengths of lasers (p<0.001). However, expression value of the TGF-β was not affected by irradiation of different wavelengths of lasers (p>0.05). The highest PDGF expression was detected in neodymium-doped yttrium aluminum garnet (Nd:YAG) laser group (p<0.05), and there were no statistically significant differences among the other groups (p>0.05). The highest bFGF expression was detected in 980-nm diode and Nd:YAG laser groups (p<0.05), and there were no statistically significant differences among the other groups (p>0.05). These findings suggest that low-level Nd:YAG and 980-nm diode laser therapy accelerate the wound healing process by changing the expression of PDGF and bFGF genes responsible for the stimulation of the cell proliferation and fibroblast growth.
The Journal of Rehabilitation Research and Development, 2004
We investigated the effects of electrical stimulation (ES) and laser treatment on wound healing in rats. A randomized-controlled trial, conducted at the Experimental and Clinical Research Centre of Erciyes University (Kayseri, Turkey), divided 124 healthy female Swiss-Albino rats into four groups. A 6 cm linear incision was made at the dorsal skin of all rats. Group 1 was given a constant direct current of 300 µA for 30 min per day. The current was applied in negative polarity for the first 3 days and in positive polarity for the next 7 days. Group 3 received a full-contact, continuous galliumarsenide (GaAs) laser therapy, with a wavelength of 904 nm, an energy density of 1 J/cm 2 , and an average power of 6 mW for 10 min per day. The remaining two groups (Groups 2 and 4) were considered the control groups and received sham treatment. All groups were treated for 10 days. Histopathologic and biochemical evaluations were conducted on 10 rats from each group on the 4th and 10th days, and wound breaking strength was measured for biomechanical evaluation on the 25th day of the study. Both ES and laser treatment proved significantly effective in the inflammatory phase compared with control groups (p < 0.05); however, the ES was even more effective than laser treatment, with more significant results (p < 0.05). In the proliferation and maturation phases, while ES and laser treatment were both found to be significantly effective treatment methods compared with the control groups, no statistically significant difference was observed between the two treatment groups (p > 0.05). Although ES and laser treatment both were effective in the maturation phase, increasing wound breaking strength compared with their control groups (p < 0.05), there was no statistically significant difference between the two treatment groups (p > 0.05). We conclude that ES and laser treatment both have beneficial effects during the inflammatory, proliferation, and maturation phases of a wound. Both ES and laser treatment can be used successfully in decubitis ulcers and chronic wounds, in combination with conventional therapies such as daily care and debridement of wounds; however, ES has more beneficial effects during the inflammatory phase in some parameters than laser treatment.
A histological study of the effect of the low level laser therapy on wound healing
In this study we show an approach for wound healing process based on using of low level laser therapy, in order to enhance the healing rate of wounds. The low power laser (LPL) has been introduced also to solve problems associated with scar formation after completing the healing process. In this study the wound healing process rate was enhanced by using the illumination of 650 nm, 5 mW diode laser in CW and 2.5 mW maximum average power pulse modes with 1 MHz frequency and 50% duty cycle. The low power laser light biostimulates the wounded area which was made on the back of many mice. The healing process was histologically studied during fourteen days to find out the differences between the laser illuminated groups of wounds and other group of wounds (control). From the results, we found out that the pulse diode laser is more efficient than continuous diode laser in enhancing the wound healing process within shorter time.
Effect of low power laser on incisional wound healing
Iranian endodontic journal, 2006
The effectiveness of low power lasers for incisional wound healing, because of conflicting results of previous research studies, is uncertain. Therefore, this study was carried out to evaluate low power laser effects on incisional wound healing. Incisional wound was produced on thirty-six mature male guinea pigs under general and local anesthesia. In half of the cases, HeNe laser radiations were used for five minutes and the rest were left untreated Animals were divided into six groups of six animals each that were killed after 3, 5 and 14 days. After histopathology processing and H&E staining, specimens were examined for acute and chronic inflammations, epithelial cell migration, epithelial seal and barrier formation, fibroblast migration, fibrosis, clot formation and granulation tissue formation. Mann-Whitney U and the Wilcoxon tests were used for statistical analysis. Statistically significant differences were found between fibroblast migration, acute and chronic inflammation of ...