de Medeiros Melyssa Lima, Araújo-Filho Irami, da Silva Efigênia Maria Nogueira, de Sousa Queiroz Wennye Scarlat, Soares Ciro Dantas, de Carvalho Maria Goretti Freire, Maciel Maria Aparecida Medeiros
Potiguar University Laureate International Universities, Campus Salgado Filho, 59075-000, Natal, RN, Brazil.
Faculty of Physiotherapy, Potiguar University Laureate International Universities, Campus Salgado Filho, 59075-000, Natal, RN, Brazil.
Lasers Med Sci. 2017 Jan;32(1):35-43. doi: 10.1007/s10103-016-2080-y. Epub 2016 Sep 20.
Low-level laser therapy (LLLT) induces anti-inflammatory and angiogenic activities in wound healing. However, the mechanism of action and optimal parameters require further clarification. In this study, we investigated the effects of LLLT on wound healing matrix metalloproteinase (MMP)-2 immunoexpression and angiogenic processes. Twenty female Wistar rats were randomly divided into four groups (n = 5) according to the treatments as follows. CG7 and CG14 were control groups at days 7 and 14, respectively, which received physiological saline (0.9 % NaCl daily). LG7 and LG14 were laser therapy groups at days 7 and 14, respectively, which received two (LG7) or four (LG14) LLLT applications (40 mW; 660 nm; 4 J/cm). A dorsal skin sample in the wound area (measuring 2 cm) was removed after the experimental period, and then the animals were euthanized. The specimens were processed for qualitative and quantitative histological analyses and measurement of MMP-2 expression in the dermis and epidermis. A persistent crust and moderate number of inflammatory cells were found in CG7 and CG14 groups. In the LG14 group, wounds demonstrated complete re-epithelization at the remodeling phase. Angiogenesis and MMP-2 expression were higher in LLLT-treated groups, particularly the LG14 group, which correlated according to the Spearman correlation test. LLLT improves wound healing by enhancing neocollagenesis, increasing the amount of new vessels formed in the tissue (neoangiogenesis), and modulating MMP-2 expression. Epidermal overexpression of MMP-2 was correlated to angiogenic processes.
低强度激光疗法（LLLT）在伤口愈合过程中具有抗炎和促血管生成活性。然而，其作用机制和最佳参数仍需进一步阐明。在本研究中，我们调查了LLLT对伤口愈合过程中基质金属蛋白酶（MMP）-2免疫表达和血管生成过程的影响。将20只雌性Wistar大鼠根据以下治疗方法随机分为四组（n = 5）。CG7和CG14分别为第7天和第14天的对照组，每天接受生理盐水（0.9% NaCl）。LG7和LG14分别为第7天和第14天的激光治疗组，接受两次（LG7）或四次（LG14）LLLT照射（40 mW；660 nm；4 J/cm）。实验期结束后，切除伤口区域（2 cm）的背部皮肤样本，然后对动物实施安乐死。对标本进行定性和定量组织学分析，并测量真皮和表皮中MMP-2的表达。在CG7和CG14组中发现有持续的痂皮和中等数量的炎性细胞。在LG14组中，伤口在重塑期显示出完全的上皮再形成。在接受LLLT治疗的组中，尤其是LG14组，血管生成和MMP-2表达更高，根据Spearman相关性检验二者具有相关性。LLLT通过增强新胶原形成、增加组织中形成的新血管数量（新生血管形成）以及调节MMP-2表达来促进伤口愈合。MMP-2的表皮过表达与血管生成过程相关。
