Low-level laser therapy modulates cyclo-oxygenase-2 expression during bone repair in rats

Abstract

The goal of this study was to analyze the role of cyclo-oxygenase-2 following bone repair in rats submitted to low-level laser therapy. A total of 48 rats underwent surgery to inflict bone defects in their tibias having been randomly distributed into two groups: negative control and laser exposed group, i.e., the animals were treated with low-level laser therapy by means of gallium arsenide laser at 16 J/cm(2). The animals were killed after 48 h, 7 days, 14 days, or 21 days. The tibias were removed for morphological, morphometric, and immunohistochemistry analysis for cyclo-oxygenase-2. Statistical significant differences (P < 0.05) were observed in the quality of bone repair and quantity of formed bone between groups 14 days after surgery in the laser exposed group. In the same way, cyclo-oxygenase-2 immunoreactivity was more intense in bone cells for intermediate periods evaluated in this group. Taken together, such results suggest that low-level laser therapy is able to improve bone repair in the tibia of rats after 14 days of surgery as a result of an up-regulation for cyclo-oxygenase-2 expression in bone cells.

Effects of low-level laser therapy on the expression of osteogenic genes during the initial stages of bone healing in rats: a microarray analysis

“…In this context, several studies demonstrated that LLLT had a positive effect in the process of bone consolidation in experimental models in rats [9,23,24]. These findings are in line with the results of the current study, which revealed that LLLT was able to modulate the inflammatory process in the area of the bone defect and to produce an earlier deposition of granulation tissue and newly formed bone.…”

“…In addition, it is important to emphasize that the energy of the laser 2.8 J used in this study had a positive result on bone metabolism at the site of the injury. It is possible to find in literature a wide range of fluencies and energy of laser irradiation used by different authors on bone healing and fractures [9,23,24,40]. In a recent study, Batista et al, [46] used 830 nm laser irradiation, at 6 J, and presented a positive local biostimulative effect in the early stage of bone healing.…”

Effects of biosilicate and bioglass 45S5 on tibial bone consolidation on rats: a biomechanical and a histological study

“…An additional control group, that remained empty, was included. Recently, we have applied this methodology with success in rats exposed to laser treated or not with anti-inflammatory drugs [12,13].…”

Avaliação de diferentes protocolos de aplicação do laser de baixa intensidade associado ou não ao osso bovino inorgânico (Bio-Oss®) na cicatrização de defeitos ósseos criados cirurgicamente em calvárias de ratos. Estudo histológico e hist

“…Os materiais de regeneração óssea têm sido testados em defeitos cirúrgicos de diferentes tamanhos, sejam em tíbia (Matsumoto et al, 2009;Fernandes et al, 2013), fêmur Weber et al, 2006) e calvária (Marques et al, 2015;Cunha et al, 2014). A evolução da cicatrização que ocorrerá é em grande parte dependente do tamanho do defeito realizado (Hjörting-Hansen, 1971;Simons, 1980).…”

“…Até o momento, não existe consenso quanto ao melhor modo de utilização do LBI na regeneração óssea , com uma diversidade de protocolos relatada na literatura (Lopes et al, 2007;Matsumoto et al, 2009;Pereira et al 2009;Gharoudhi et al, 2014) e, também a utilização de vários modelos experimentais, com diferentes resultados (Rochkind et al,m 2004;Pereira et al, 2009;Fernandes et al, 2013;Ghahroudi et al, 2014;Marques et al, 2015).…”