The influence of low-level laser therapy on biomodulation of collagen and elastic fibers

O estudo da terapia a laser de baixa densidade de energia sobre os diversos constituintes da matriz extracelular ?? crucial para o entendimento do processo cicatricial sob esse agente. Todavia, pouco se sabe sobre a interfer??ncia do laser em rela????o ??s fibras col??genas e el??sticas. Realizaram-se ferimentos cut??neos padronizados no dorso de setenta e dois ratos Wistar e, em seguida, aplica????o pontual do raio laser de baixa pot??ncia do tipo Arseneto de G??lio-Alum??nio (Ga-Al-As) com diferentes densidades de energia. Os animais foram sacrificados com 24, 48 e 72 horas e aos 5, 7 e 14 dias. Procedeu-se ?? an??lise das sec????es teciduais coradas por hematoxilina-eosina, s??rius vermelho e orce??na. Observou-se, que nos grupos submetidos ?? terapia a laser, houve maior redu????o do edema e infiltrado inflamat??rio. Os animais tratados apresentaram uma maior express??o de fibras col??genas e el??sticas, embora sem signific??ncia estat??stica (p > 0,05). No tratamento com a flu??ncia de 4 J/cm?? observaram-se melhores resultados do que naquele em que foi utilizada a flu??ncia de 8 J/cm??. Neste estudo, p??de-se concluir que o laser contribuiu para uma maior express??o de fibras col??genas e el??sticas durante o processo cicatricial.The study of low-level laser therapy upon extracellular matrix elements is important to understand the wound healing process under this agent. However, little is known about the interference of laser light in relation to collagen and elastic fibers. Cutaneous wounds were performed on the back of 72 Wistar rats and a Ga-Al-As low-level laser was punctually applied with different energy densities. The animals were killed after 24, 48, 72 hours and 5, 7 and 14 days. Tissues were stained with hematoxilin-eosin, sirius red fast green and orcein and then analyzed. It was observed that the treated group exhibited larger reduction of edema and inflammatory infiltrate. The treated animals presented a larger expression of collagen and elastic fibers, although without statistical significance (p > 0.05). Treatment with a dosage of 4 J/cm?? exhibited more expressive results than that with 8 J/cm??. In this study, the authors concluded that low-level laser therapy contributed to a larger expression of collagen and elastic fibers during the early phases of the wound healing process