The low level laser therapy effect on the remodeling of bone extracellular matrix

Photochem Photobiol. Sep-Oct 2012;88(5):1293-301. doi: 10.1111/j.1751-1097.2012.01172.x. Epub 2012 Jul 9.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcian Blue
  • Animals
  • Bone Matrix / injuries
  • Bone Matrix / radiation effects*
  • Bone Regeneration / radiation effects*
  • Chondroitin Sulfates / biosynthesis
  • Extracellular Matrix Proteins / genetics
  • Extracellular Matrix Proteins / metabolism
  • Femur / injuries
  • Femur / radiation effects*
  • Gene Expression / radiation effects
  • Hyaluronic Acid / biosynthesis
  • Immunohistochemistry
  • Integrin-Binding Sialoprotein / genetics
  • Integrin-Binding Sialoprotein / metabolism
  • Lasers
  • Low-Level Light Therapy*
  • Male
  • Microscopy, Fluorescence
  • Osteocalcin / genetics
  • Osteocalcin / metabolism
  • Osteonectin / genetics
  • Osteonectin / metabolism
  • Periodic Acid-Schiff Reaction
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism
  • Rats
  • Rats, Wistar


  • Dmp1 protein, rat
  • Extracellular Matrix Proteins
  • Ibsp protein, rat
  • Integrin-Binding Sialoprotein
  • Osteonectin
  • Phosphoproteins
  • Osteocalcin
  • Hyaluronic Acid
  • Chondroitin Sulfates
  • Alcian Blue