College for Photomedicine

College for Photomedicine

03.03.2019 • Veterinary Medicine   ← back to overview

Are there studies on PBM in veterinary medicine?

In addition to hundreds of so-called "animal studies" (preclinical studies in mice and rats), there are also targeted indication studies for veterinary medicine. However, these are small in comparison with human literature.

With over 4000 human studies and soon 600 RCT (randomized clinical trials), PBM is so strongly represented in human literature that veterinary studies seem almost irrelevant. After all, all mammals are. Veterinary medicine does not come off very well in comparison.
The following studies are examples of veterinary research:

 

Vet Comp Orthop Traumatol. 2017 Jan 16;30(1):46-53. doi: 10.3415/VCOT-15-12-0198. Epub 2016 Dec 9. 
Preoperative low level laser therapy in dogs undergoing tibial plateau levelling osteotomy: A blinded, prospective, randomized clinical trial. 
Rogatko CP, Baltzer WI1, Tennant R. Abstract 

OBJECTIVES: To evaluate the influence of preoperative low-level laser therapy (LLLT) on therapeutic outcomes of dogs undergoing tibial plateau levelling osteotomy (TPLO). METHODS: Healthy dogs undergoing TPLO were randomly assigned to receive either a single preoperative LLLT treatment (800-900 nm dual wavelength, 6 W, 3.5 J/cm2, 100 cm2 area) or a sham treatment. Lameness assessment and response to manipulation, as well as force plate analysis, were performed preoperatively, then again at 24 hours, two weeks, and eight weeks postoperatively. Radiographic signs of healing of the osteo-tomy were assessed at eight weeks postoperatively. 
RESULTS: Twenty-seven dogs (27 stifles) were included and no major complications occurred. At eight weeks postoperatively, a significant difference in peak vertical force analysis was noted between the LLLT (39.6% ± 4.7%) and sham groups (28.9% ± 2.6%), (p <0.01 Time, p <0.01 L). There were no significant differences noted between groups for all other parameters. The age of dogs in the LLLT group (6.6 ± 1.6 years) was greater than that for the sham group (4.5 ± 2.0, p <0.01). Although not significant, a greater proportion of LLLT dogs (5/8) had healed at the eight-week time point than in the sham group (3/12) despite the age difference (p = 0.11) Clinical significance: The results of this study demonstrate that improved peak vertical force could be related to the preoperative use of LLLT for dogs undergoing TPLO at eight weeks postoperatively. The use of LLLT may improve postoperative return to function following canine osteotomies and its use is recommended. 

Lasers Med Sci. 2016 Aug;31(6):1245-50. doi: 10.1007/s10103-016-1966-z. Epub 2016 Jun 7. Effects of photobiomodulation therapy (PBMT) on bovine sperm function. 
Siqueira AF1, Maria FS1, Mendes CM1,2, Hamilton TR1, Dalmazzo A3, Dreyer TR4, da Silva HM4, Nichi M3, Milazzotto MP4, Visintin JA2, Assumpção ME5. 

ABSTRACT: Fertilization rates and subsequent embryo development rely on sperm factors related to semen quality and viability. Photobiomodulation therapy (PBMT) is based on emission of electromagnetic waves of a laser optical system that interact with cells and tissues resulting in biological effects. This interaction is mediated by photoacceptors that absorb the electromagnetic energy. Effects are dependent of irradiation parameters, target cell type, and species. In sperm, PBMT improves several features like motility and viability, affecting sperm aerobic metabolism and energy production. The aim of this study was to investigate, under same conditions, how different output powers (5, 7.5, and 10 mW) and time of irradiation (5 and 10 min) of laser (He-Ne laser, 633 nm) may affect frozen/thawed bovine sperm functions. Results showed significant effects depending on power while using 10 min of irradiation on motility parameters and mitochondrial potential. However, no effect was observed using 5 min of irradiation, regardless of power applied. In conclusion, PBMT is effective to modulate bovine sperm function. The effectiveness is dependent on the interaction between power applied and duration of irradiation, showing that these two parameters simultaneously influence sperm function. In this context, when using the same fluency and energy with different combinations of power and time of exposure, we observed distinct effects, revealing that biological effects should be also based on simple parameters rather than only composite parameters such as fluency, irradiance and energy. Laserirradiation of frozen/thawed bovine semen led to an increase on mitochondrial function and motility parameters that could potentially improve fertility rates. 

Pol J Vet Sci. 2015;18(3):523-31. doi: 10.1515/pjvs-2015-0068. 
Effect of low-energy laser irradiation and antioxidant supplementation on cell apoptosis during skeletal muscle post-injury regeneration in pigs. 
Otrocka-Domagała I, Mikołajczyk A, Paździor-Czapula K, Gesek M, Rotkiewicz T, Mikiewicz M. 

ABSTRACT: The aim of this study was to evaluate the effect of low-energy laser irradiation, coenzyme Q10 and vitamin E supplementation on the apoptosis of macrophages and muscle precursor cells during skeletal muscle regeneration after bupivacaine-induced injury. The experiment was conducted on 75 gilts, divided into 5 experimental groups: I--control, II--low-energy laser irradiation, III--coenzyme Q10, IV--coenzyme Q10 and vitamin E, V--vitamin E. Muscle necrosis was induced by injection of 0.5% bupivacaine hydrochloride. The animals were euthanized on subsequent days after injury. Samples were formalin fixed and processed routinely for histopathology. Apoptosis was detected using the TUNEL method. The obtained results indicate that low-energy laser irradiation has a beneficial effect on macrophages and muscle precursor cell activity during muscle post-injury regeneration and protects these cells against apoptosis. Vitamin E has a slightly lower protective effect, limited mainly to the macrophages. Coenzyme Q10 co-supplemented with vitamin E increases the activity of macrophages and muscle precursor cells, myotube and young muscle formation. Importantly, muscle precursor cells seem to be more sensitive to apoptosis than macrophages in the environment of regenerating damaged muscle. 

Photomed Laser Surg. 2016 Nov;34(11):516-524. Epub 2016 Jan 7. 
Low-Level Laser Therapy to the Bone Marrow Reduces Scarring and Improves Heart Function Post-Acute Myocardial Infarction in the Pig. 
Blatt A1,2, Elbaz-Greener GA1,2, Tuby H3, Maltz L3, Siman-Tov Y4, Ben-Aharon G4, Copel L5, Eisenberg I6, Efrati S4, Jonas M7, Vered Z1,2, Tal S5, Goitein O8, Oron U3. 

Abstract 
OBJECTIVE: Cell therapy for myocardial repair is one of the most intensely investigated strategies for treating acute myocardial infarction (MI). The aim of the present study was to determine whether low-level laser therapy (LLLT) application to stem cells in the bone marrow (BM) could affect the infarcted porcine heart and reduce scarring following MI. 
METHODS: MI was induced in farm pigs by percutaneous balloon inflation in the left coronary artery for 90 min. Laser was applied to the tibia and iliac bones 30 min, and 2 and 7 days post-induction of MI. Pigs were euthanized 90 days post-MI. The extent of scarring was analyzed by histology and MRI, and heart function was analyzed by echocardiography. 
RESULTS: The number of c-kit+ cells (stem cells) in the circulating blood of the laser-treated (LT) pigs was 2.62- and 2.4-fold higher than in the non-laser-treated (NLT) pigs 24 and 48 h post-MI, respectively. The infarct size [% of scar tissue out of the left ventricle (LV) volume as measured from histology] in the LT pigs was 3.2 ± 0.82%, significantly lower, 68% (p < 0.05), than that (16.6 ± 3.7%) in the NLT pigs. The mean density of small blood vessels in the infarcted area was significantly higher [6.5-fold (p < 0.025)], in the LT pigs than in the NLT ones. Echocardiography (ECHO) analysis for heart function revealed the left ventricular ejection fraction in the LT pigs to be significantly higher than in the NLT ones. 
CONCLUSIONS: LLLT application to BM in the porcine model for MI caused a significant reduction in scarring, enhanced angiogenesis and functional improvement both in the acute and long term phase post-MI. 

Acta Cir Bras. 2015 Sep;30(9):611-6. doi: 10.1590/S0102-865020150090000005. 
The influence of low-level laser irradiation on spinal cord injuries following ischemia-reperfusion in rats. 
Sotoudeh A1, Jahanshahi A2, Zareiy S3, Darvishi M4, Roodbari N5, Bazzazan A6. 1Faculty of Veterinary Science, Islamic Azad University, Kerman, IR.2IAU, Kerman, IR. 3Aerospace and Subaquatic Medicine School, AJA University of Medical Sciences, Tehran, IR. 4Department of Infection Medicine, AJA University of Medical Sciences, Tehran, IR.5Faculty of Experimental Science, Islamic Azad University, Kerman, IR.6IAU, Semnan, IR. 

Abstract 
PURPOSE: To investigate if low level laser therapy (LLLT) can decrease spinal cord injuries after temporary induced spinal cord ischemia-reperfusion in rats because of its anti-inflammatory effects. 
METHODS: Forty eight rats were randomized into two study groups of 24 rats each. In group I, ischemic-reperfusion (I-R) injury was induced without any treatment. Group II, was irradiated four times about 20 minutes for the following three days. The lesion site directly was irradiated transcutaneously to the spinal direction with 810 nm diode laser with output power of 150 mW. Functional recovery, immunohistochemical and histopathological changes were assessed. 
RESULTS: The average functional recovery scores of group II were significantly higher than that the score of group I (2.86 ± 0.68, vs 1.38 ± 0.09; p<0.05). Histopathologic evaluations in group II were showed a mild changes in compare with group I, that suggested this group survived from I-R consequences. Moreover, as seen from TUNEL results, LLLT also protected neurons from I-R-induced apoptosis in rats. 
CONCLUSION: Low level laser therapy was be able to minimize the damage to the rat spinal cord of reperfusion-induced injury. 

Lasers Med Sci. 2015 Dec;30(9):2319-24. doi: 10.1007/s10103-015-1813-7. Epub 2015 Sep 28. 
A comparative study of red and blue light-emitting diodes and low-level laser in regeneration of the transected sciatic nerve after an end to end neurorrhaphy in rabbits. 
Takhtfooladi MA1, Sharifi D2. 

Abstract This study aimed at evaluating the effects of red and blue light-emitting diodes (LED) and low-level laser (LLL) on the regeneration of the transected sciatic nerve after an end-to-end neurorrhaphy in rabbits. Forty healthy mature male New Zealand rabbits were randomly assigned into four experimental groups: control, LLL (680 nm), red LED (650 nm), and blue LED (450 nm). All animals underwent the right sciatic nerve neurotmesis injury under general anesthesia and end-to-end anastomosis. The phototherapy was initiated on the first postoperative day and lasted for 14 consecutive days at the same time of the day. On the 30th day post-surgery, the animals whose sciatic nerves were harvested for histopathological analysis were euthanized. The nerves were analyzed and quantified the following findings: Schwann cells, large myelinic axons, and neurons. In the LLL group, as compared to other groups, an increase in the number of all analyzed aspects was observed with significance level (P < 0.05). This finding suggests that postoperative LLL irradiation was able to accelerate and potentialize the peripheral nerve regeneration process in rabbits within 14 days of irradiation. 
BMC Complement Altern Med. 2015 Mar 24;15:78. doi: 10.1186/s12906-015-0593-8.

In vitro exposure to very low-level laser modifies expression level of extracellular matrix protein RNAs and mitochondria dynamics in mouse embryonic fibroblasts. 
Giuliani A1, Lorenzini L2, Alessandri M3, Torricella R4, Baldassarro VA5, Giardino L6,7, Calzà L8,9. 

Abstract 
BACKGROUND: Low-level lasers working at 633 or 670 nm and emitting extremely low power densities (Ultra Low Level Lasers - ULLL) exert an overall effect of photobiostimulation on cellular metabolism and energy balance. In previous studies, it was demonstrated that ULLL pulsed emission mode regulates neurite elongation in vitro and exerts protective action against oxidative stress. 
METHODS: In this study the action of ULLL supplied in both pulsed and continuous mode vs continuous LLL on fibroblast cultures (Mouse Embryonic Fibroblast-MEF) was tested, focusing on mitochondria network and the expression level of mRNA encoding for proteins involved in the cell-matrix adhesion. 
RESULTS: It was shown that ULLL at 670 nm, at extremely low average power output (0.21 mW/ cm(2)) and dose (4.3 mJ/ cm(2)), when dispensed in pulsed mode (PW), but not in continuous mode (CW) supplied at both at very low (0.21 mW/cm(2)) and low levels (500 mW/cm(2)), modifies mitochondria network dynamics, as well as expression level of mRNA encoding for selective matrix proteins in MEF, e.g. collagen type 1α1 and integrin α5. 
CONCLUSIONS: We suggest that pulsatility, but not energy density, is crucial in regulating expression level of collagen I and integrin α5 in fibroblasts by ULLL. 
Freier Artikel: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387590/pdf/12906_2015_Article_593.pdf 
Acta Cir Bras. 2015 Mar;30(3):204-8. doi: 10.1590/S0102-865020150030000007. 

Use of low-power laser to assist the healing of traumatic wounds in rats. 
Calisto FC1, Calisto SL2, Souza AP3, França CM4, Ferreira AP5, Moreira MB6. 

Abstract 
PURPOSE: To investigate the morphological aspects of the healing of traumatic wounds in rats using low-power laser. 
METHODS: Twenty four non isogenic, young adult male Wistar rats (Rattus norvegicus) weighing between 200 and 300 g was used. The animals were randomly distributed into two groups: Control (GC) and Laser (GL), with 12 animals each. After shaving, anesthesia was performed in the dorsal region and then a surgical procedure using a scalpel was carried out to make the traumatic wound. GL received five sessions of laser therapy in consecutive days using the following laser parameters: wavelength 660 nm, power 100 mW, dose 10 J/cm2. The wounds were evaluated through measurement of the area and depth of the wound (MW) and histological analysis (HA). 
RESULTS: When comparing the GC with the GL in MW there was a difference in area (p<0.001) and depth (p=0.003) measurement of the wounds in GL. The laser group presented more epithelization than GC (p=0.03). The other histological parameters were similar. 
CONCLUSION: The healing of wounds in rats was improved with the use of the laser.

Image license: shutterstock

Mit über 4000 Humanstudien und bald 600 RCT (randomized clinical trials) ist die PBM in der Humanliteratur so stark vertreten, dass Veterinär-Studien fast irrelevant erscheinen. Schließlich sind alle Säugetiere. Die Veterinärmedizin kommt im Vergleich eher schlecht weg. 
Die folgenden Studien sind Beispiele dafür, dass auch in der Veterinärmedizin geforscht wird:

Vet Comp Orthop Traumatol. 2017 Jan 16;30(1):46-53. doi: 10.3415/VCOT-15-12-0198. Epub 2016 Dec 9.
Preoperative low level laser therapy in dogs undergoing tibial plateau levelling osteotomy: A blinded, prospective, randomized clinical trial. 
Rogatko CP, Baltzer WI1, Tennant R. Abstract 

OBJECTIVES: To evaluate the influence of preoperative low-level laser therapy (LLLT) on therapeutic outcomes of dogs undergoing tibial plateau levelling osteotomy (TPLO). METHODS: Healthy dogs undergoing TPLO were randomly assigned to receive either a single preoperative LLLT treatment (800-900 nm dual wavelength, 6 W, 3.5 J/cm2, 100 cm2 area) or a sham treatment. Lameness assessment and response to manipulation, as well as force plate analysis, were performed preoperatively, then again at 24 hours, two weeks, and eight weeks postoperatively. Radiographic signs of healing of the osteo-tomy were assessed at eight weeks postoperatively. 
RESULTS: Twenty-seven dogs (27 stifles) were included and no major complications occurred. At eight weeks postoperatively, a significant difference in peak vertical force analysis was noted between the LLLT (39.6% ± 4.7%) and sham groups (28.9% ± 2.6%), (p <0.01 Time, p <0.01 L). There were no significant differences noted between groups for all other parameters. The age of dogs in the LLLT group (6.6 ± 1.6 years) was greater than that for the sham group (4.5 ± 2.0, p <0.01). Although not significant, a greater proportion of LLLT dogs (5/8) had healed at the eight-week time point than in the sham group (3/12) despite the age difference (p = 0.11) Clinical significance: The results of this study demonstrate that improved peak vertical force could be related to the preoperative use of LLLT for dogs undergoing TPLO at eight weeks postoperatively. The use of LLLT may improve postoperative return to function following canine osteotomies and its use is recommended. 

Lasers Med Sci. 2016 Aug;31(6):1245-50. doi: 10.1007/s10103-016-1966-z. Epub 2016 Jun 7. Effects of photobiomodulation therapy (PBMT) on bovine sperm function.
Siqueira AF1, Maria FS1, Mendes CM1,2, Hamilton TR1, Dalmazzo A3, Dreyer TR4, da Silva HM4, Nichi M3, Milazzotto MP4, Visintin JA2, Assumpção ME5. 

ABSTRACT: Fertilization rates and subsequent embryo development rely on sperm factors related to semen quality and viability. Photobiomodulation therapy (PBMT) is based on emission of electromagnetic waves of a laser optical system that interact with cells and tissues resulting in biological effects. This interaction is mediated by photoacceptors that absorb the electromagnetic energy. Effects are dependent of irradiation parameters, target cell type, and species. In sperm, PBMT improves several features like motility and viability, affecting sperm aerobic metabolism and energy production. The aim of this study was to investigate, under same conditions, how different output powers (5, 7.5, and 10 mW) and time of irradiation (5 and 10 min) of laser (He-Ne laser, 633 nm) may affect frozen/thawed bovine sperm functions. Results showed significant effects depending on power while using 10 min of irradiation on motility parameters and mitochondrial potential. However, no effect was observed using 5 min of irradiation, regardless of power applied. In conclusion, PBMT is effective to modulate bovine sperm function. The effectiveness is dependent on the interaction between power applied and duration of irradiation, showing that these two parameters simultaneously influence sperm function. In this context, when using the same fluency and energy with different combinations of power and time of exposure, we observed distinct effects, revealing that biological effects should be also based on simple parameters rather than only composite parameters such as fluency, irradiance and energy. Laserirradiation of frozen/thawed bovine semen led to an increase on mitochondrial function and motility parameters that could potentially improve fertility rates. 

Pol J Vet Sci. 2015;18(3):523-31. doi: 10.1515/pjvs-2015-0068.
Effect of low-energy laser irradiation and antioxidant supplementation on cell apoptosis during skeletal muscle post-injury regeneration in pigs.
Otrocka-Domagała I, Mikołajczyk A, Paździor-Czapula K, Gesek M, Rotkiewicz T, Mikiewicz M.

ABSTRACT: The aim of this study was to evaluate the effect of low-energy laser irradiation, coenzyme Q10 and vitamin E supplementation on the apoptosis of macrophages and muscle precursor cells during skeletal muscle regeneration after bupivacaine-induced injury. The experiment was conducted on 75 gilts, divided into 5 experimental groups: I--control, II--low-energy laser irradiation, III--coenzyme Q10, IV--coenzyme Q10 and vitamin E, V--vitamin E. Muscle necrosis was induced by injection of 0.5% bupivacaine hydrochloride. The animals were euthanized on subsequent days after injury. Samples were formalin fixed and processed routinely for histopathology. Apoptosis was detected using the TUNEL method. The obtained results indicate that low-energy laser irradiation has a beneficial effect on macrophages and muscle precursor cell activity during muscle post-injury regeneration and protects these cells against apoptosis. Vitamin E has a slightly lower protective effect, limited mainly to the macrophages. Coenzyme Q10 co-supplemented with vitamin E increases the activity of macrophages and muscle precursor cells, myotube and young muscle formation. Importantly, muscle precursor cells seem to be more sensitive to apoptosis than macrophages in the environment of regenerating damaged muscle. 

Photomed Laser Surg. 2016 Nov;34(11):516-524. Epub 2016 Jan 7. 
Low-Level Laser Therapy to the Bone Marrow Reduces Scarring and Improves Heart Function Post-Acute Myocardial Infarction in the Pig. 
Blatt A1,2, Elbaz-Greener GA1,2, Tuby H3, Maltz L3, Siman-Tov Y4, Ben-Aharon G4, Copel L5, Eisenberg I6, Efrati S4, Jonas M7, Vered Z1,2, Tal S5, Goitein O8, Oron U3. 

Abstract 
OBJECTIVE: Cell therapy for myocardial repair is one of the most intensely investigated strategies for treating acute myocardial infarction (MI). The aim of the present study was to determine whether low-level laser therapy (LLLT) application to stem cells in the bone marrow (BM) could affect the infarcted porcine heart and reduce scarring following MI. 
METHODS: MI was induced in farm pigs by percutaneous balloon inflation in the left coronary artery for 90 min. Laser was applied to the tibia and iliac bones 30 min, and 2 and 7 days post-induction of MI. Pigs were euthanized 90 days post-MI. The extent of scarring was analyzed by histology and MRI, and heart function was analyzed by echocardiography.
RESULTS: The number of c-kit+ cells (stem cells) in the circulating blood of the laser-treated (LT) pigs was 2.62- and 2.4-fold higher than in the non-laser-treated (NLT) pigs 24 and 48 h post-MI, respectively. The infarct size [% of scar tissue out of the left ventricle (LV) volume as measured from histology] in the LT pigs was 3.2 ± 0.82%, significantly lower, 68% (p < 0.05), than that (16.6 ± 3.7%) in the NLT pigs. The mean density of small blood vessels in the infarcted area was significantly higher [6.5-fold (p < 0.025)], in the LT pigs than in the NLT ones. Echocardiography (ECHO) analysis for heart function revealed the left ventricular ejection fraction in the LT pigs to be significantly higher than in the NLT ones.
CONCLUSIONS: LLLT application to BM in the porcine model for MI caused a significant reduction in scarring, enhanced angiogenesis and functional improvement both in the acute and long term phase post-MI. 

Acta Cir Bras. 2015 Sep;30(9):611-6. doi: 10.1590/S0102-865020150090000005.
The influence of low-level laser irradiation on spinal cord injuries following ischemia-reperfusion in rats.
Sotoudeh A1, Jahanshahi A2, Zareiy S3, Darvishi M4, Roodbari N5, Bazzazan A6. 1Faculty of Veterinary Science, Islamic Azad University, Kerman, IR.2IAU, Kerman, IR. 3Aerospace and Subaquatic Medicine School, AJA University of Medical Sciences, Tehran, IR. 4Department of Infection Medicine, AJA University of Medical Sciences, Tehran, IR.5Faculty of Experimental Science, Islamic Azad University, Kerman, IR.6IAU, Semnan, IR.

Abstract
PURPOSE: To investigate if low level laser therapy (LLLT) can decrease spinal cord injuries after temporary induced spinal cord ischemia-reperfusion in rats because of its anti-inflammatory effects.
METHODS: Forty eight rats were randomized into two study groups of 24 rats each. In group I, ischemic-reperfusion (I-R) injury was induced without any treatment. Group II, was irradiated four times about 20 minutes for the following three days. The lesion site directly was irradiated transcutaneously to the spinal direction with 810 nm diode laser with output power of 150 mW. Functional recovery, immunohistochemical and histopathological changes were assessed.
RESULTS: The average functional recovery scores of group II were significantly higher than that the score of group I (2.86 ± 0.68, vs 1.38 ± 0.09; p<0.05). Histopathologic evaluations in group II were showed a mild changes in compare with group I, that suggested this group survived from I-R consequences. Moreover, as seen from TUNEL results, LLLT also protected neurons from I-R-induced apoptosis in rats.
CONCLUSION: Low level laser therapy was be able to minimize the damage to the rat spinal cord of reperfusion-induced injury. 

Lasers Med Sci. 2015 Dec;30(9):2319-24. doi: 10.1007/s10103-015-1813-7. Epub 2015 Sep 28.
A comparative study of red and blue light-emitting diodes and low-level laser in regeneration of the transected sciatic nerve after an end to end neurorrhaphy in rabbits.
Takhtfooladi MA1, Sharifi D2. 

Abstract This study aimed at evaluating the effects of red and blue light-emitting diodes (LED) and low-level laser (LLL) on the regeneration of the transected sciatic nerve after an end-to-end neurorrhaphy in rabbits. Forty healthy mature male New Zealand rabbits were randomly assigned into four experimental groups: control, LLL (680 nm), red LED (650 nm), and blue LED (450 nm). All animals underwent the right sciatic nerve neurotmesis injury under general anesthesia and end-to-end anastomosis. The phototherapy was initiated on the first postoperative day and lasted for 14 consecutive days at the same time of the day. On the 30th day post-surgery, the animals whose sciatic nerves were harvested for histopathological analysis were euthanized. The nerves were analyzed and quantified the following findings: Schwann cells, large myelinic axons, and neurons. In the LLL group, as compared to other groups, an increase in the number of all analyzed aspects was observed with significance level (P < 0.05). This finding suggests that postoperative LLL irradiation was able to accelerate and potentialize the peripheral nerve regeneration process in rabbits within 14 days of irradiation. 
BMC Complement Altern Med. 2015 Mar 24;15:78. doi: 10.1186/s12906-015-0593-8.

In vitro exposure to very low-level laser modifies expression level of extracellular matrix protein RNAs and mitochondria dynamics in mouse embryonic fibroblasts.
Giuliani A1, Lorenzini L2, Alessandri M3, Torricella R4, Baldassarro VA5, Giardino L6,7, Calzà L8,9. 

Abstract 
BACKGROUND: Low-level lasers working at 633 or 670 nm and emitting extremely low power densities (Ultra Low Level Lasers - ULLL) exert an overall effect of photobiostimulation on cellular metabolism and energy balance. In previous studies, it was demonstrated that ULLL pulsed emission mode regulates neurite elongation in vitro and exerts protective action against oxidative stress.
METHODS: In this study the action of ULLL supplied in both pulsed and continuous mode vs continuous LLL on fibroblast cultures (Mouse Embryonic Fibroblast-MEF) was tested, focusing on mitochondria network and the expression level of mRNA encoding for proteins involved in the cell-matrix adhesion.
RESULTS: It was shown that ULLL at 670 nm, at extremely low average power output (0.21 mW/ cm(2)) and dose (4.3 mJ/ cm(2)), when dispensed in pulsed mode (PW), but not in continuous mode (CW) supplied at both at very low (0.21 mW/cm(2)) and low levels (500 mW/cm(2)), modifies mitochondria network dynamics, as well as expression level of mRNA encoding for selective matrix proteins in MEF, e.g. collagen type 1α1 and integrin α5.
CONCLUSIONS: We suggest that pulsatility, but not energy density, is crucial in regulating expression level of collagen I and integrin α5 in fibroblasts by ULLL. 
Freier Artikel: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387590/pdf/12906_2015_Article_593.pdf
Acta Cir Bras. 2015 Mar;30(3):204-8. doi: 10.1590/S0102-865020150030000007.

Use of low-power laser to assist the healing of traumatic wounds in rats.
Calisto FC1, Calisto SL2, Souza AP3, França CM4, Ferreira AP5, Moreira MB6. 

Abstract
PURPOSE: To investigate the morphological aspects of the healing of traumatic wounds in rats using low-power laser.
METHODS: Twenty four non isogenic, young adult male Wistar rats (Rattus norvegicus) weighing between 200 and 300 g was used. The animals were randomly distributed into two groups: Control (GC) and Laser (GL), with 12 animals each. After shaving, anesthesia was performed in the dorsal region and then a surgical procedure using a scalpel was carried out to make the traumatic wound. GL received five sessions of laser therapy in consecutive days using the following laser parameters: wavelength 660 nm, power 100 mW, dose 10 J/cm2. The wounds were evaluated through measurement of the area and depth of the wound (MW) and histological analysis (HA). 
RESULTS: When comparing the GC with the GL in MW there was a difference in area (p<0.001) and depth (p=0.003) measurement of the wounds in GL. The laser group presented more epithelization than GC (p=0.03). The other histological parameters were similar.
CONCLUSION: The healing of wounds in rats was improved with the use of the laser.

Bildlizenz: shutterstock

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