ABSTRACT
PURPOSE: To evaluate the in vivo response of photobiomodulation therapy associated with norbixin-based poly(hydroxybutyrate) membrane (PHB) in tenotomized calcaneal tendon. METHODS: Thirty rats were randomly allocated to six groups (n=5 each): LED groups (L1, L2 and L3) and membrane + LED groups (ML1, ML2 and ML3). The right calcaneal tendons of all animals were sectioned transversely and were irradiated with LED daily, one hour after surgery every 24 hours, until the day of euthanasia. At the end of the experiments the tendons were removed for histological analysis. RESULTS: The histological analysis showed a significant reduction in inflammatory cells in the ML1, ML2 and ML3 groups (p=0.0056, p=0.0018 and p<0.0001, respectively) compared to those in the LED group. There was greater proliferation of fibroblasts in the ML1 (p<0.0001) and L3 (p<0.0001) groups. A higher concentration of type I collagen was also observed in the ML1 group (p=0.0043) replacing type III collagen. CONCLUSION: Photobiomodulation in association with norbixin-based PHB membrane led to control of the inflammatory process. However, it did not favor fibroblast proliferation and did not optimize type I collagen formation in the expected stage of the repair process.
Subject(s)
Achilles Tendon/radiation effects , Carotenoids/pharmacology , Hydroxybutyrates/pharmacology , Low-Level Light Therapy/methods , Tendinopathy/radiotherapy , Tenotomy/methods , Achilles Tendon/drug effects , Achilles Tendon/surgery , Animals , Collagen/pharmacology , Collagen Type I/analysis , Collagen Type I/drug effects , Collagen Type III/analysis , Collagen Type III/drug effects , Drug Evaluation, Preclinical , Fibroblasts/chemistry , Fibroblasts/drug effects , Male , Prohibitins , Random Allocation , Rats , Rats, Wistar , Wound Healing/drug effects , Wound Healing/radiation effectsABSTRACT
Abstract Purpose: To evaluate the in vivo response of photobiomodulation therapy associated with norbixin-based poly(hydroxybutyrate) membrane (PHB) in tenotomized calcaneal tendon. Methods: Thirty rats were randomly allocated to six groups (n=5 each): LED groups (L1, L2 and L3) and membrane + LED groups (ML1, ML2 and ML3). The right calcaneal tendons of all animals were sectioned transversely and were irradiated with LED daily, one hour after surgery every 24 hours, until the day of euthanasia. At the end of the experiments the tendons were removed for histological analysis. Results: The histological analysis showed a significant reduction in inflammatory cells in the ML1, ML2 and ML3 groups (p=0.0056, p=0.0018 and p<0.0001, respectively) compared to those in the LED group. There was greater proliferation of fibroblasts in the ML1 (p<0.0001) and L3 (p<0.0001) groups. A higher concentration of type I collagen was also observed in the ML1 group (p=0.0043) replacing type III collagen. Conclusion: Photobiomodulation in association with norbixin-based PHB membrane led to control of the inflammatory process. However, it did not favor fibroblast proliferation and did not optimize type I collagen formation in the expected stage of the repair process.
Subject(s)
Animals , Male , Rats , Achilles Tendon/radiation effects , Carotenoids/pharmacology , Low-Level Light Therapy/methods , Tendinopathy/radiotherapy , Tenotomy/methods , Hydroxybutyrates/pharmacology , Achilles Tendon/surgery , Achilles Tendon/drug effects , Wound Healing/drug effects , Wound Healing/radiation effects , Random Allocation , Collagen/pharmacology , Rats, Wistar , Collagen Type I/analysis , Collagen Type I/drug effects , Collagen Type III/analysis , Collagen Type III/drug effects , Drug Evaluation, Preclinical , Fibroblasts/drug effects , Fibroblasts/chemistry , ProhibitinsABSTRACT
The objective of this review was to analyze original articles about the effects of therapy with LED in experimental models of calcaneal tendon lesions of rats. The search was performed in the period from February to May 2018, in the following electronic databases: MEDLINE, SciELO, and LILACS, besides the Google Scholar, using the descriptors "Achilles tendon", "Rats", "LED", "Tendinopathy", and "Low-level Light Therapy", as well as their matching parts in the Portuguese and Spanish languages, related to and in association with the relevant terms to the content sought. From the descriptors used 215 works were found. After application of eligibility criteria 8 works were selected, in which positive results were found after the application of the LED. Regarding the main results found with phototherapy, we observed a significant reduction in inflammation. Only one article mentioned little reduction of inflammation. In relation to the number of sessions, there was wide variation, with an average of approximately 5 sessions every 24 hours. Studies in this review pointed out, therefore, positive results in the repair of the calcaneal tendon after therapy with irradiation LED; however, carrying out more experimental studies that help the standardization of parameters to be used in this therapy for further clinical studies becomes necessary.
