title: The low level laser therapy effect on the remodeling of bone extracellular matrix.
abstract: The low level laser therapy (LLLT) has been used as an option to accelerate the regeneration of bone tissue. In this study, both femurs of male Wistar rats (30 animals) were injured with a drill and the effect of LLLT using a laser diode (100 mW at 660 nm) in the bone matrix on the left paw measured. LLLT effect on the healing bone tissue matrix was evaluated by a combination of immunohistochemical histomorphometry, confocal immunofluorescence microscopy and isolation and characterization of glycosaminoglycans. Histomorphometric analysis showed that LLLT increased bone matrix and showing more organized. Alcian Blue and PAS staining seems to suggest differential glycosaminoglycans and glycoproteins. The data showed increased expression of chondroitin sulfate and hyaluronic acid, after reduction as the LLLT and mature bone, resembling the expression of osteonectin and biglycan. The difference in expression of siblings (DMP-1, OPN and BSP) is in accordance with the repair accelerated bone formation after the application of LLLT as compared with control. The expression of osteonectin and osteocalcin supports their role in bone mineralization protein, indicating that LLLT accelerates this process. The overall data show that LLLT bone changes dynamic array, shortening the time period involved in the bone repair.
authors.affiliation: Department of Orthopedics and Traumatology, Universidade Federal de São Paulo, São Paulo, Brazil. luizmerli@uol.com.br
authors.forename: Luiz Antonio
authors.initials: LA
authors.lastname: de Souza Merli
authors.forename: Valquíria Pereira
authors.initials: VP
authors.lastname: de Medeiros
authors.forename: Leny
authors.initials: L
authors.lastname: Toma
authors.forename: Rejane Daniele
authors.initials: RD
authors.lastname: Reginato
authors.forename: Eduardo
authors.initials: E
authors.lastname: Katchburian
authors.forename: Helena B
authors.initials: HB
authors.lastname: Nader
authors.forename: Flavio
authors.initials: F
authors.lastname: Faloppa
mesh_terms: D000423:Alcian Blue; D000818:Animals; D001857:Bone Matrix / Q000293:injuries / Q000528:radiation effects*; D001861:Bone Regeneration / Q000528:radiation effects*; D002809:Chondroitin Sulfates / Q000096:biosynthesis; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D005269:Femur / Q000293:injuries / Q000528:radiation effects*; D015870:Gene Expression / Q000528:radiation effects; D006820:Hyaluronic Acid / Q000096:biosynthesis; D007150:Immunohistochemistry; D058574:Integrin-Binding Sialoprotein / Q000235:genetics / Q000378:metabolism; D007834:Lasers; D028022:Low-Level Light Therapy; D008297:Male; D008856:Microscopy, Fluorescence; D015675:Osteocalcin / Q000235:genetics / Q000378:metabolism; D015676:Osteonectin / Q000235:genetics / Q000378:metabolism; D010503:Periodic Acid-Schiff Reaction; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: C081635:Dmp1 protein, rat; D016326:Extracellular Matrix Proteins; C546873:Ibsp protein, rat; D058574:Integrin-Binding Sialoprotein; D015676:Osteonectin; D010750:Phosphoproteins; D015675:Osteocalcin; D006820:Hyaluronic Acid; D002809:Chondroitin Sulfates; D000423:Alcian Blue