Wound healingTissue repair
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Photomedicine and Laser Surgery Volume 29, Number 8, 2011
Irradiation at 636
nm Positively Affects Diabetic Wounded and Hypoxic Cells
in Vitro
Palesa R.
Sekhejane, MTech, Nicolette N. Houreld, DTech, and Heidi
Abrahamse, Ph.D.
Abstract
Objective:
This study investigated the
effect of low-intensity laser irradiation (LILI) on
pro-inflammatory cytokines involved in wound healing
processes in diabetes and hypoxia. Background data: Diabetes
is associated with impaired wound healing and a prolonged
inflammatory phase. Pro-inflammatory cytokines such as
interleukin (IL)-1b, tumor necrosis factor (TNF)-a and IL-6
are elevated in diabetes. LILI has been reported to
accelerate wound healing and decrease inflammatory
cytokines.
Methods: A
human skin fibroblast cell line (WS1) was used in vitro.
Cells were exposed to various insults, namely, wounding, and
a diabetic or hypoxic environment. Experimental cells were
exposed to an energy density of 5 J/cm2 using a continuous
wave 636-nm diode laser at an average power of 95mW, an
illuminated area of 9.05 cm2, and an irradiance of 11 mW/cm2
(irradiation time, 476 sec). The effect of laser irradiation
on cytokine expression was examined at 1 or 24 h
postirradiation. Cellular morphology, viability,
proliferation, and cytokine expression (IL-1b, IL-6, and
TNF-a) were investigated. Translocation of nuclear factor –
kappa B (NF-kB) was also determined.
Results:
There was a higher rate of migration in irradiated wounded
cultures, and irradiated hypoxic cells showed an improvement
in cellular morphology. All cell models showed an increase
in proliferation. Normal wounded cells showed a decrease in
apoptosis, TNF-a, and IL-1b. Diabetic wounded cells showed
an increase in viability and a decrease in apoptosis and
IL-1b, whereas hypoxic cells showed an increase in viability
and IL-6, and a decrease in apoptosis and TNF-a. NF-kB was
translocated into the nucleus post-irradiation.
Conclusions:
Phototherapy resulted in hastened wound closure, increased
proliferation, and normalization of cellular function. The
decrease in the different pro-inflammatory cytokines and
NF-kB translocation was model and time dependent. Overall,
laser irradiation resulted in a reduction in inflammatory
cytokines and directed cells into the cell survival pathway.
Laser Therapy Vol. 12 Official Journal
of the World Association for Laser Therapy (WALT)
Thermographic
study of Low Level Laser Therapy for acute-phase injury
Yoshimi
Asagai, M.D. 1,
Atsuhiro Imakiire, M.D.2, Toshio Ohshiro, M.D.3,
1. Shinano
Handicapped Children`s Hospital Shimosuwa, Nagano, Japan
2.
Department of Orthopaedic Surgery, Tokyo Medical University
Shinjuku, Tokyo, Japan
3. Japan
Medical Laser Laboratory, Shinanomachi, Tokyo, Japan
ABstract
Background and Objectives:
Acute-phase injury is generally treated by
localized cooling of the region, and rarely by the active
use of low level laser therapy (LLLT) in Japan.
Thermographic studies of acutephase injury revealed that
circulatory disturbances at the site of trauma occurred due
to swelling and edema on the day following the injury, and
that skin temperature was high at the site of the trauma and
low at the periphery.
Results: Following LLLT, circulatory
disturbances rapidly improved, while temperature in the high
temperature zone around the site of trauma fell by 3 degrees
on the average, but at the periphery the low temperature
rose by 3 degrees on the average to nearly normal skin
temperature. Clinically, swelling and edema improved. LLLT
was also useful in treating necrosis of the skin in the
wound area and in accelerating healing of surgical wounds of
paralytic feet, which are prone to delayed, wound healing
and also wounds due to spoke injury.
Conclusion: LLLT is useful in treating
swelling and edema in acute-phase injury and in accelerating
healing of surgical wounds.
Influence of the Combination of Infrared and Red Laser
Light on the Healing of Cutaneous Wounds Infected by
Staphylococcus aureus
Nicole R.S. Santos, Ph.D., 1
Joa˜o Batista de M. Sobrinho, Ph.D.,2 Paulo F. Almeida,
Ph.D.,3 Adriana A.
Ribeiro, D.D.S.,1
Maria C.T. Cangussu´ , Ph.D.,4
Jean N. dos Santos, Ph.D.,5
and Antonio L.B. Pinheiro, Ph.D., M.DentSci, D.D.S.1,6,7
Abstract
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 redþinfrared
laser light. Laser phototherapy was carried out with a diode
[l680nm/790 nm, power (P)=30
mW/40mW, continuous wave laser, Ø=3mm, power density (P)=424
and 566mW/ cm2,
time=11.8/8.8 sec, E=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/cm2).
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
680 to790 nm.
A Randomized Clinical Trial on the Effect
of Low-Level Laser Therapy on Chronic Diabetic Foot Wound
Healing
A Preliminary Report
Ahmad Kaviani, M.D., 1
Gholamreza Esmaeeli Djavid, M.D.,2
Leila Ataie-Fashtami, M.D.,3 Mohsen Fateh, M.D., M.P.H.,4
Maryam Ghodsi, M.D.,5
Maliheh Salami, B.S.,4
Nasrin Zand, M.D.,3 Nasim Kashef, Ph.D.,6
and Bagher Larijani, M.D.5
Abstract
Background and Objectives:
Low-level laser therapy (LLLT) has been shown to promote
chronic wound healing in conditions of reduced
microcirculation. In this preliminary study, we report the
results of using LLLT to heal foot ulcers in patients with
diabetes mellitus.
Materials and Methods:
Twenty-three patients with a diabetic foot wound for at
least 3 months were included in this double-blind randomized
clinical trial. Patients were randomized to receive placebo
treatment (n¼10)
or LLLT (n¼13) (685 nm, energy density 10 J/cm2)
in addition to conventional therapy. Patients were followed
for 20 weeks. Ulcer size reduction and the number of
patients with complete healing were compared between the
LLLT and placebo groups.
Results:
There were no significant differences in baseline
characteristics of patients and foot ulcers receiving LLLT
and placebo treatment. At week 4, the size of ulcers
decreased significantly in the LLLT group (
p¼0.04).
After 20 weeks, in the LLLT group, eight patients had
complete healing and in the placebo group only three
patients experienced complete wound healing. The mean time
of complete healing in LLLT patients (11 weeks) was less
than that in placebo patients (14 weeks) though the
difference was not statistically significant.
Conclusions:
The study provides evidence that LLLT can accelerate the
healing process of chronic diabetic foot ulcers, and it can
be presumed that LLLT may shorten the time period needed to
achieve complete healing.
Photomedicine and Laser Surgery
Volume 29, Number 1, 2011
Comparative Effects of
Low-Intensity Pulsed Ultrasound and Low-Level Laser Therapy
on Injured Skeletal Muscle
Ana Claudia Muniz Renno´ ,
Ph.D., 1 Renata Luri
Toma,2 Suellen Maurin Feitosa,2 Kelly Fernandes,2, Paulo S.
Bossini, Ph.D.,2 Poliani de Oliveira,2 Nivaldo Parizotto,
Ph.D.,2 and Daniel Araki Ribeiro, Ph.D.1
Abstract
Objective: The main purpose of
this study was to compare the effects of low-intensity
pulsed ultrasound (US) and low-level laser therapy (LLLT) on
injured skeletal muscle after cryolesion by means of
histopathological analysis and immunohistochemistry for
cyclo-oxygenase-2 (COX-2). Background and Methods:
Thirty-five male Wistar rats were randomly distributed into
four groups: intact control group with uninjured and
untreated animals; injured control group with muscle injury
and no treatment; LLLT-treated group with muscle injury
treated with 830-nm laser; and US-treated group with muscle
injury treated with US. Treatments started 24 h postsurgery
and were performed during six sessions.
Results: LLLT-treated animals
presented minor degenerative changes of muscle tissue.
Exposure to US reduced tissue injuries induced by
cryolesion, but less effectively than LLLT. A large number
of COX-2 positive cells were found in untreated injured
rats, whereas COX-2 immunoexpression was lower in both LLLT-
and US-treated groups.
Conclusion: This study revealed
that both LLLT and US therapies have positive effects on
muscle metabolism after an injury in rats, but LLLT seems to
produce a better response.
Photomedicine and
Laser Surgery, Volume 27, Number 2, 2009
Low-Level Laser
Therapy Increases Transforming Growth Factor-_2
Expression and Induces Apoptosis of Epithelial Cells During
the Tissue Repair Process
Adeir Moreira
Rocha Júnior,1
Beatriz
Juliúo Vieira,2
Luís Carlos
Ferreira de Andrade,3
and
Fernando Monteiro Aarestrup4
Abstract
Background
Data:
Low-level laser
therapy (LLLT) has been reported to modulate the healing of
wounds by inducing an increase in mitotic activity,
fibroblast number, synthesis of collagen, and
neovascularization.
Objective:
In
the present study we evaluated the effect of LLLT on
expression of TGF-_2,
an immunosuppressive cytokine, at the site of tissue repair,
using an experimental rat model to study cutaneous wound
healing. In addition, we also investigated the presence of
apoptotic cells in epithelial and connective tissue.
Materials
and Methods:
Thirty male Wistar
rats were divided into two groups: group 1, which was
subjected to surgical skin wounds only (n
_ 15), and
group 2, which was subjected to surgical skin wounds
followed by LLLT (n
_ 15). In
group 2, the LLLT was given with these parameters: 15 mW of
power, a dose of 3.8 J/cm2,
for 15 sec for three applications. At 10 d post-surgery and
laser application the animals were sacrificed with an
overdose of anesthetic and tissue samples from the wounds
were submitted to immunohistochemistry and
insitu
detection of
apoptosis.
Results:
Most of the inflammatory cells and fibroblasts were TGF-_2–positive,
and many apoptotic epithelial cells and fibroblasts were
seen in the tissue samples from the LLLT-treated animals.
However, a few apoptotic epithelial cells and fibroblasts
were also seen in the samples obtained from control animals.
Conclusion:
Our
results indicate that LLLT may be an important inducer of
apoptosis during the process of tissue repair. In addition,
we demonstrated that LLTT has an immunomodulatory effect on
TGF-_2
expression
at
sites of wound healing.
Photomedicine and Laser Surgery
Histological Assessment of the Effect of Laser Irradiation on Skin Wound Healing in Rats
Aug 2006, Vol. 24, No. 4: 480-488
Peter Gál Department of Medical Biophysics, Faculty of Medicine, Pavol Jozef šafárik University in Ko[scaron]ice, Košice, Slovak Republic.
Boris Vidinský Department of Medical Biophysics, Faculty of Medicine, Pavol Jozef šafárik University in Ko[scaron]ice, Košice, Slovak Republic.
Tomáš Toporcer Department of Medical Biophysics, Faculty of Medicine, Pavol Jozef šafárik University in Ko[scaron]ice, Košice, Slovak Republic.
Michal Mokrý Department of Medical Biophysics, Faculty of Medicine, Pavol Jozef šafárik University in Ko[scaron]ice, Košice, Slovak Republic.
ŠTefan Mozeš, D.V.M., Ph.D. Institute of Animal Physiology, Slovak Academy of Sciences, Košice, Slovak Republic.
FrantišEk Longauer, M.D., Ph.D. Department of Forensic Medicine, Faculty of Medicine, Pavol Jozef šafárik University in Košice, Košice, Slovak Republic.
Prof. Ján Sabo, Ph.D. Department of Medical Biophysics, Faculty of Medicine, Pavol Jozef šafárik University in Ko[scaron]ice, Košice, Slovak Republic.
Objective: The purpose of this study was to evaluate, from the histological point of view, the effect of diode laser irradiation on skin wound healing in Sprague-Dawley rats.
Background Data: Various biological effects have been described in different studies after low-level laser therapy (LLLT).
Methods: Two parallel full thickness skin incisions were performed on the back of each rat (n = 49) and immediately sutured. After surgery, one wound of each rat was exposed to laser irradiation (continuous mode, 670 nm, daily dose 30 J/cm2), whereas the parallel wound was not irradiated and served as control. Both wounds were removed 24, 48, 72, 96, 120, 144, and 168 h after surgery and routinely fixed and embedded in paraffin sections, stained with hematoxylin and eosin, van Gieson, periodic acid Schiff + periodic acid Schiff diastase, Mallory's phosphotungstic hematoxylin, and azur and eosin, and histopathologically evaluated.
Results: As compared to nonirradiated control wounds, laser stimulation shortened the inflammatory phase as well as accelerated the proliferative and maturation phase, and positively stimulated the regeneration of injured epidermis and the reparation of injured striated muscle.
Conclusion: LLLT at 670 nm positively influences all phases of rat skin wound healing.
Photomedicine and Laser Surgery
Comparison between Wound Healing in Induced Diabetic and Non diabetic Rats after Low-Level Laser Therapy
Aug 2006, Vol. 24, No. 4: 474-479
Sylvia Bicalho Rabelo , D.D.S., M.S.D. Instituto de Pesquisa e Desenvolvimento (IP&D), Universidade do Vale do Paraiba (UNIVAP), São José dos Campos, São Paulo, Brazil.
Dr. Antonio Balbin Villaverde , Ph.D. Instituto de Pesquisa e Desenvolvimento (IP&D), Universidade do Vale do Paraiba (UNIVAP), São José dos Campos, São Paulo, Brazil.
Renataamadei Nicolau , D.D.S., Ph.D. Instituto de Pesquisa e Desenvolvimento (IP&D), Universidade do Vale do Paraiba (UNIVAP), São José dos Campos, São Paulo, Brazil.
Miguel A. Castillo Salgado , Ph.D. Faculdade de Odontologia (FOSJC), Universidade Estadual Paulista (UNESP), São José dos Campos, São Paulo, Brazil.
Milene Da Silva Melo , M.S.D. Instituto de Pesquisa e Desenvolvimento (IP&D), Universidade do Vale do Paraiba (UNIVAP), São José dos Campos, São Paulo, Brazil.
Marcos Tadeu T. Pacheco , Ph.D. Instituto de Pesquisa e Desenvolvimento (IP&D), Universidade do Vale do Paraiba (UNIVAP), São José dos Campos, São Paulo, Brazil.
Objective: The aim of this work was to compare the effect of low-level laser therapy (LLLT) on the wound healing process in nondiabetic and diabetic rats.
Background Data: Among the clinical symptoms caused by diabetes mellitus, a delay in wound healing is a potential risk for patients. It is suggested that LLLT can improve wound healing.
Methods: The tissue used for this study was extracted from animals suffering from diabetes, which was induced by Streptozotocin®, and from nondiabetic rats. Animals were assembled into two groups of 25 rats each (treated and control) and further subdivided into two groups: diabetic (n = 15) and nondiabetic (n = 10). A full-thickness skin wound was made on the dorsum area, with a round 8-mm holepunch. The treated group was irradiated by a HeNe laser at 632.8 nm, with the following parameters: 15 mW, exposition time of 17 sec, 0.025 cm2 irradiated area, and energy density of 10 J/cm2. Square full-thickness skin samples (18 mm each side, including both injured and noninjured tissues) were obtained at 4, 7, and 15 days after surgery and analyzed by qualitative and quantitative histological methods.
Results: Quantitative histopathological analysis confirmed the results of the qualitative analysis through histological microscope slides. When comparing tissue components (inflammatory cells, vessels and fibroblast/area), we found that treated animals had a less intense inflammatory process than controls.
Conclusion: Results obtained by both qualitative and quantitative analyses suggested that irradiation of rats with HeNe (632.8 nm), at the tested dose, promoted efficient wound healing in both nondiabetic and diabetic rats as, compared to the control group.
Photoengineering of Tissue Repair in Skeletal and Cardiac Muscles
- Apr 2006, Vol. 24, No. 2: 111-120 , Photomedicine and Laser Surgery
-
-
Dr. Uri Oron, Ph.D.
Department of Zoology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.
This review discusses the application of He-Ne laser irradiation to injured muscles at optimal power densities and optimal timing, which was found to significantly enhance (twofold) muscle regeneration in rats and, even more, in the cold-blooded toads. Multiple and frequent (daily) application of the laser in the toad model was found to be less effective than irradiation on alternate days. It was found that in the ischemia/reperfusion type of injury in the skeletal leg muscles (3 h of ischemia), infrared Ga-Al-As laser irradiation reduced muscle degeneration, increased the cytoprotective heat shock proteins (HSP-70i) content, and produced a twofold increase in total antioxidants. In vitro studies on myogenic satellite cells (SC) revealed that phototherapy restored their proliferation. Phototherapy induced mitogen-activated protein kinase/extracellular signalregulated protein kinase (MAPK/ERK) phosphorylation in these cells, probably by specific receptor phosphorylation. Cell cycle entry and the accumulation of satellite cells around isolated single myofibers cultured in vitro was also stimulated by phototherapy. Phototherapy also had beneficial effects on mouse, rat, dog and pig ischemic heart models. In these models, it was found that phototherapy markedly and significantly reduced (50–70%) the scar tissue formed after induction of myocardial infarction (MI). The phototherapeutic effect was associated with reduction of ventricular dilatation, preservation of mitochondria and elevation of HSP- 70i and ATP in the infarcted zone.
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Protection of Skeletal Muscles from Ischemic Injury: Low-Level Laser Therapy Increases Antioxidant Activity
Jun 2005, Vol. 23, No. 3: 273-277, Photomedicine and Laser Surgery
- Dorit Avni, M.Sc.
- Department of Zoology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.
- Sara Levkovitz, Ph.D.
- Department of Zoology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.
- Lidya Maltz, M.Sc.
- Department of Zoology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.
- Uri Oron, Ph.D.
- Department of Zoology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.
Objective: The aim of this study was to investigate the effect of low-level laser therapy (LLLT) on ischemic-reperfusion (I-R) injury in the gastrocnemius muscle of the rat. Background Data: Ischemic injury in skeletal muscle is initiated during hypoxia and is aggravated by reoxygenation during blood reperfusion and accumulation of cytotoxic reactive oxygen superoxides. LLLT has been found to biostimulate various biological processes, such as attenuation of ischemic injury in the heart. Materials and Methods: The injury was induced in the gastrocnemius muscles of 106 rats by complete occlusion of the blood supply for 3 h, followed by reperfusion. Another group of intact rats served to investigate the effect of LLLT on intact nonischemic muscles. Creatine phosphokinase, acid phosphatase, and heat shock protein were determined 7 days after I-R injury and antioxidant levels 2 h after reperfusion.
Results: Laser irradiation (Ga-As, 810 nm) was applied to the muscles immediately and 1 h following blood supply occlusion. It was found that laser irradiation markedly protects skeletal muscles from degeneration following acute I-R injury. This was evident by significantly (p < 0.05) higher content of creatine phosphokinase activity and lower (p < 0.05) activity of acid phosphatase in the LLLT-treated muscles relative to the injured non-irradiated ones. The content of antioxidants and heat shock proteins was also higher (p < 0.05) in the LLLT-treated muscles relative to that of injured non-irradiated muscles.
Conclusion: The present study describes for the first time the ability of LLLT to significantly prevent degeneration following ischemia/reperfusion injury in skeletal muscles, probably by induction of synthesis of antioxidants and other cytoprotective proteins, such as hsp-70i. The elevation of antioxidants was also evident in intact muscle following LLLT. The above phenomenon may also be of clinical relevance in scheduled surgery or microsurgery requiring extended tourniquet applications to skeletal muscle followed by reperfusion.
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Kawalec J S, Hetherington J, Pfennigwerth C et al.
Effect of a diode laser on wound healing by using diabetic and nondiabetic mice.
Journal of Foot and Ankle Surgery. 2004; 43 (4): 214-220.
The purpose of this study was to evaluate therapy with a high power 980 nm GaAlAs laser for wound healing. Using genetically diabetic and non-diabetic mice, two 6 mm wounds were created on the back of each mouse by using a punch biopsy. The mice were assigned to 1 of 4 subgroups for laser treatment at different fluence and frequency of treatment: 5 W (18 J/cm²) every 2 days, 5 W (18 J/cm²) every 4 days, 10 W (36 J/cm²) every 2 days, and 10 W (36 J/cm²) every 4 days. In addition, control mice were used and the wounds were allowed to heal naturally. Wound healing was evaluated on days 5, 12, and 19 by percentage of wounds healed and percent wound closure. A maximum of 5 mice per subgroup were killed at days 7, 14, and 21, and histology was conducted on the wound sites. For diabetic mice receiving 5 W every 2 days, the percentage of wounds healed after 19 days was 100% versus 40% in the control group. Only 20% of wounds in the 10 W diabetic subgroups achieved healing during the same period. For the subgroups whose wounds did not completely heal, all but the 10 W every 2 days subgroup had average closure of >90%. The 100% closure for the 5 W every 2 days subgroup was significantly greater than the other subgroups. For non-diabetic mice, 100% of the wounds in the 5 W every 4 days and control subgroups were completely healed, whereas 90% of the wounds from the 5 W every 2 days and the 10 W every 4 days subgroups were completely healed. In the latter 2 subgroups, wound closure was 99.4% and 98.8%, respectively. These differences were not significant. The histological results confirmed these findings.
In conclusion, treatment at 18 J/cm² shows a beneficial effect on wound healing in diabetic mice and does not have a detrimental effect in non-diabetic mice.
Wound healing of animal and human body sport and traffic accident injuries using low-level laser therapy treatment: a randomized clinical study of seventy-four patients with control group.
Simunovic Z; Ivankovich AD; Depolo A
Journal of clinical laser medicine & surgery; VOL: 18 (2); p. 67-73 /200004/
Department of Anesthesiology, La Caritá Medical Center, Laser Center, Locarno, Switzerland. info@lasermedico.ch
BACKGROUND AND OBJECTIVE: The main objective of current animal and clinical studies was to assess the efficacy of low level laser therapy (LLLT) on wound healing in rabbits and humans.
STUDY DESIGN/MATERIALS AND METHODS: In the initial part of our research we conducted a randomized controlled animal study, where we evaluated the effects of laser irradiation on the healing of surgical wounds on rabbits. The manner of the application of LLLT on the human body are analogous to those of similar physiologic structure in animal tissue, therefore, this study was continued on humans.
Clinical study was performed on 74 patients with injuries to the following anatomic locations: ankle and knee, bilaterally, Achilles tendon; epicondylus; shoulder; wrist; interphalangeal joints of hands, unilaterally. All patients had had surgical procedure prior to LLLT. Two types of laser devices were used: infrared diode laser (GaAlAs) 830 nm continuous wave for treatment of trigger points (TPs) and HeNe 632.8 nm combined with diode laser 904-nm pulsed wave for scanning procedure. Both were applied as monotherapy during current clinical study. The results were observed and measured according to the following clinical parameters: redness, heat, pain, swelling and loss of function, and finally postponed to statistical analysis via chi2 test.
RESULTS: After comparing the healing process between two groups of patients, we obtained the following results: wound healing was significantly accelerated (25%-35%) in the group of patients treated with LLLT. Pain relief and functional recovery of patients treated with LLLT were significantly improved comparing to untreated patients.
CONCLUSION: In addition to accelerated wound healing, the main advantages of LLLT for postoperative sport- and traffic-related injuries include prevention of side effects of drugs, significantly accelerated functional recovery, earlier return to work, training and sport competition compared to the control group of patients, and cost benefit.
ose and wavelength of laser light have influence on the repair of cutaneous wounds.
Mendez TM; Pinheiro AL; Pacheco MT; Nascimento PM; Ramalho LM
Journal of clinical laser medicine & surgery; VOL: 22 (1); p. 19-25 /200402/
IP&D, Univap & School of Dentistry, Universidade do Vale do Paraíba, São José dos Campos, São Paulo, Brazil.
OBJECTIVE: The objective of the present study was to compare histologically the effect of GaAlAs (lambda 830 nm, phi approximately 2 mm(2), 35 mW) and InGaAlP (lambda 685 nm, phi approximately 2 mm(2), 35 mW) lasers, alone or in association with doses of 20 or 50 J/cm(2) on cutaneous wounds in the dorsum of the Wistar rat.
Background Data: The healing time of surgical wounds is of extreme importance and it is usually associated with a post-operative period free of infection and with less pain and inflammation.
MATERIALS AND METHODS: Sixty Wistar rats were divided into seven groups: Group I - control (non-irradiated); Group II - lambda 685 nm, 20 J/cm(2); Group III - lambda 830 nm, 20 J/cm(2); Group IV - lambda 685 nm and lambda 830 nm, 20 J/cm(2); Group V - lambda 685 nm, 50 J/cm(2)); Group VI - lambda 830 nm, 50 J/cm(2); and Group VII - lambda 685 nm and 830 nm, 50 J/cm(2). The animals were sacrificed 3, 5, and 7 days after surgery.
RESULTS: Light microscopic analysis using H&E and Picrosírius stains showed that, at the end of the experimental period, irradiated subjects showed increased collagen production and organization when compared to non-irradiated controls. Inflammation was still present in all groups at this time.
Effect of low intensity helium-neon (He-Ne) laser irradiation on diabetic wound healing dynamics.
Maiya GA; Kumar P; Rao L
Photomedicine and laser surgery; VOL: 23 (2); p. 187-90 /200504/
Department of Physiotherapy, MAHE University, Manipal, India. ajmaiya@yahoo.com
OBJECTIVE: The aim of this study was to determine the effect of low-energy He-Ne laser treatment on wound healing dynamics (histological and biochemical) in diabetic rats.
BACKGROUND DATA: Low-energy laser photostimulation at certain wavelengths can enhance tissue repair by releasing growth factors from fibroblasts and can facilitate the healing process of diabetic wounds.
MATERIALS AND METHODS: A circular 4 cm2 excisional wound was created on the dorsum of the experimentally (Alloxan)-induced diabetic rats. In the study group (N = 24) the wound was treated with He-Ne laser (632.8 nm wavelength) at a dose of 4.8 J/cm2 for 5 days a week until the wound healed completely. The control group (N = 24) was sham-irradiated. The results were statistically analyzed by an independent t test for biochemical analysis and the nonparametric Mann-Whitney U test for histopathological parameters.
RESULTS: The analysis of the biochemical parameters and histopathological parameters of the wounds showed that the laser-treated group healed faster and better as compared to the control group (p < 0.0001). The laser-treated group healed on average by the 18th day whereas, the control group healed on average by the 59th day.
CONCLUSION: Laser photostimulation promotes the tissue repair process of diabetic wounds.
Influence of low level laser therapy on wound healing and its biological action upon myofibroblasts.
Medrado AR; Pugliese LS; Reis SR; Andrade ZA
Lasers in surgery and medicine; VOL: 32 (3); p. 239-44 /2003/
Laboratory of Experimental Pathology, Oswaldo Cruz Foundation-Salvador, Bahia, Brazil.
alenamedrado@hotmail.com
BACKGROUND AND OBJECTIVE: In re-evaluating the effects of laser therapy in wound healing, the role of extracellular matrix elements and myofibroblasts, was analyzed.
STUDY DESIGN/MATERIALS AND METHODS: Cutaneous wounds were inflicted on the back of 72 Wistar rats. Low level laser was locally applied with different energy densities. Lesions were analyzed after 24, 48, 72 hours and 5, 7, and 14 days. Tissues were studied by histology, immunohistochemistry, and electron microscopy.
Low-level laser therapy (LLLT) efficacy in post-operative wounds.
Herascu N; Velciu B; Calin M; Savastru D; Talianu C
Photomedicine and laser surgery; VOL: 23 (1); p. 70-3 /200502/
National Institute of Research and Development for Optoelectronics INOE 2000, 1 Atomistilor St., PO Box MG5, 077125, Magurele-Bucharest, Romania.
herescu@inoe.inoe.ro
OBJECTIVE: The aim of this paper was to investigate the efficacy of low-level laser radiation (LLLR) with wavelength of 904 nm on the stimulation of the healing process of postoperative aseptic wounds (early scar).
BACKGROUND DATA: Low-level laser therapy (LLLT) has been increasingly used to treat many disorders, including wounds. However, despite such increased clinical usage, there is still controversy regarding the efficacy of this wound treatment in curent clinical practice. METHODS: LLLT has been used to treat cutting plague in the right instep and on the left foot. Both resulted from sutured wounds. The clinical evaluation by semiquantitative methods is presented. RESULTS: Clinical evaluation showed that the healing process of these postoperatively treated wounds has occurred and that the functional recovery of the patients (i.e., return to their ordinary life) was faster than without treatment.
CONCLUSION: LLLR with wavelength of 904 nm to stimulate postoperative aseptic wounds (early scar) is efficient in both cases of cutting plague.
Temperature-controlled 830-nm low-level laser therapy of experimental pressure ulcers.
Lanzafame RJ; Stadler I; Coleman J; Haerum B; Oskoui P; Whittaker M; Zhang RY
Photomedicine and laser surgery; VOL: 22 (6); p. 483-8 /200412/
The Laser Center, Rochester General Hospital, Rochester, New York, USA. ray.lanzafame@viahealth.org
OBJECTIVE: This study was performed to evaluate the effectiveness of near-infrared low-level laser therapy (LLLT) treatment of pressure ulcers under temperature-controlled conditions.
BACKGROUND DATA: Little information is available regarding the potential thermal effects of near-infrared photo-radiation during LLLT.
METHODS: Pressure ulcers were created in C57BL mice by placing the dorsal skin between two round ceramic magnetic plates (12.0 x 5.0 mm, 2.4 g, 1 K Gauss) for three 12-h cycles. Animals were divided into three groups (n = 9) for daily light therapy (830 nm, CW, 5.0 J/cm(2)) on days 3-13 post ulceration in both groups A and B. A special heat-exchange device was applied in Group B to maintain a constant temperature at the skin surface (30 degrees C).
Group C served as controls, with irradiation at 5.0 J/cm(2) using an incandescent light source. Temperature of the skin surface, and temperature alterations during treatment were monitored. The wound area was measured and the rate and time to complete healing were noted.
RESULTS: The maximum temperature change during therapy was 2.0 +/- 0.64 degrees C in Group A, 0.2 +/- 0.2 degrees C in Group B and 3.54 degrees C +/- 0.72 in Group C. Complete wound closure occurred at
18 +/- 4 days in Groups A and B
25 +/- 6 days in Group C (p
The influence of low-level laser therapy on biomodulation of collagen and elastic fibers.
Pugliese LS; Medrado AP; Reis SR; Andrade Zde A
Pesquisa odontologica brasileira =Brazilian oral research; VOL: 17 (4); p. 307-13 /2003 Oct-Dec/
Department of Basic Science, Foundation for the Development of Science, Salvador
The study of low-level laser therapy upon extracellular matrix elements is important to understand the wound healing process under this agent. However, little is known about the interference of laser light in relation to collagen and elastic fibers.
Cutaneous wounds were performed on the back of 72 Wistar rats and a Ga-Al-As low-level laser was punctually applied with different energy densities. The animals were killed after 24, 48, 72 hours and 5, 7 and 14 days. Tissues were stained with hematoxilin-eosin, sirius red fast green and orcein and then analyzed. It was observed that the treated group exhibited larger reduction of edema and inflammatory infiltrate.
The treated animals presented a larger expression of collagen and elastic fibers, although without statistical significance (p > 0.05). Treatment with a dosage of 4 J/cm(2) exhibited more expressive results than that with 8 J/cm(2). In this study, the authors concluded that low-level laser therapy contributed to a larger expression of collagen and elastic fibers during the early phases of the wound healing process.
Effects of a therapeutic laser on the ultrastructural morphology of repairing medial collateral ligament in a rat model.
Fung DT; Ng GY; Leung MC; Tay DK
Lasers in surgery and medicine; VOL: 32 (4); p. 286-93 /2003/
Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
BACKGROUND AND OBJECTIVES: Low energy laser therapy has been shown to enhance mechanical strength of healing medial collateral ligament (MCL) in rats. The present study investigated its effects on the ultrastructural morphology and collagen fibril profile of healing MCL in rats.
STUDY DESIGN/MATERIALS AND METHODS: Thirty-two mature male Sprague-Dawley (SD) rats were used. Twenty-four underwent surgical transection to their right MCLs and eight received only skin wound. Immediately after surgery, eight of the MCL transected rats were treated with a single dose of laser therapy at 63.2 J cm(-2), eight were treated with a single dose of laser therapy at 31.6 J cm(-2), the rest had no treatment and served as control. At 3 and 6 weeks after surgery, the MCLs were harvested and examined with electron microscopy for collagen fibril size, distribution, and alignment.
RESULTS: Significant differences (P < 0.001) were found in fibril diameters from the same anatomical site and time period among different groups. The mass-averaged diameters of the laser-treated (64.99-186.29 nm) and sham (64.74-204.34 nm) groups were larger than the control group (58.66-85.89 nm). The collagen fibrils occupied 42.55-59.78, 42.63-53.94, and 36.92-71.64% of the total cross-sectional areas in the laser-treated, control and sham groups, respectively. Mode obliquity was 0.53-0.84 among the three groups.
CONCLUSIONS: Single application of low energy laser therapy increases the collagen fibril size of healing MCLs in rats.
Photobiomodulation improves cutaneous wound healing in an animal model of type II diabetes.
Byrnes KR; Barna L; Chenault VM; Waynant RW; Ilev IK; Longo L; Miracco C; Johnson B; Anders JJ
Photomedicine and laser surgery; VOL: 22 (4); p. 281-90 /200408/
Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA. krb27@georgetown.edu
OBJECTIVE: We investigated the effects of photobiomodulation (PBM) on cutaneous wound healing in an animal model of type II diabetes, Psammomys obesus (Sand Rats).
BACKGROUND DATA: 632-nm light has been established as the most effective wavelength for treatment of cutaneous wounds; however, the inconsistent efficacy of PBM may be due to inadequate treatment parameter selection. METHODS: Using 632-nm light, an initial series of experiments
were done to establish optimal treatment parameters for this model. Following creation of bilateral full-thickness skin wounds, non-diabetic Sand Rats were treated with PBM of differing dosages. Wound healing was assessed according to wound closure and histological characteristics of healing. Optimal treatment parameters were then used to treat type II diabetic Sand Rats while a diabetic control group received no irradiation. In order to elucidate the mechanism behind an improvement in wound healing, expression of basic fibroblast growth factor (bFGF) was assessed.
RESULTS: Significant improvement in wound healing histology and wound closure were found following treatment with 4 J/cm(2) (16 mW, 250-sec treatments for 4 consecutive days; p < 0.05). The 4 J/cm(2) dosage significantly improved histology and closure of wounds in the diabetic group in comparison to the non-irradiated diabetic group. Quantitative analysis of bFGF expression at 36 h post-injury revealed a threefold increase in the diabetic and non-diabetic Sand Rats after PBM.
CONCLUSIONS: The results demonstrate that PBM at an energy density of 4 J/cm(2) is effective in improving the healing of cutaneous wounds in an animal model of type II diabetes, suggesting that PBM (632 nm, 4 J/cm(2)) would be effective in treating chronic cutaneous wounds in diabetic patients.
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