Carrinho Patricia M, Renno Ana Claudia Muniz, Koeke Paulo, Salate Ana Claudia Bonogne, Parizotto Nivaldo Antonio, Vidal Benedito Campos
Laboratory of Electro-Thermo-Phototherapy, Department of Physiotherapy, Federal University of São Carlos, São Carlos, Brazil.
Photomed Laser Surg. 2006 Dec;24(6):754-8. doi: 10.1089/pho.2006.24.754.
The objective of this study was to evaluate the effects of 685- and 830-nm laser irradiations, at different fluences on the healing process of Achilles tendon (Tendon calcaneo) of mice after tenotomy.
Some authors have shown that low-level laser therapy (LLLT) is able to accelerate the healing process of tendinuos tissue after an injury, increasing fibroblast cell proliferation and collagen synthesis. However, the mechanism by which LLLT acts on healing process is not fully understood.
Forty-eight male mice were divided into six experimental groups: group A, tenomized animals, treated with 685 nm laser, at the dosage of 3 J/cm(2); group B, tenomized animals, treated with 685-nm laser, at the dosage of 10 J/cm(2); group C, tenomized animals, treated with 830-nm laser, at dosage of 3 J/cm(2); group D, tenomized animals, treated with 830-nm laser, at the dosage of 10 J/cm(2); group E, injured control (placebo treatment); and group F, non-injured standard control. Animals were killed on day 13 post-tenotomy, and their tendons were surgically removed for a quantitative analysis using polarization microscopy, with the purpose of measuring collagen fibers organization through the birefringence (optical retardation [OR]).
All treated groups showed higher values of OR when compared to injured control group. The best organization and aggregation of the collagen bundles were shown by the animals of group A (685 nm, 3 J/cm(2)), followed by the animals of group C and B, and finally, the animals of group D.
All wavelengths and fluences used in this study were efficient at accelerating the healing process of Achilles tendon post-tenotomy, particularly after the 685-nm laser irradiation, at 3 J/cm(2). It suggests the existence of wavelength tissue specificity and dose dependency. Further studies are required to investigate the physiological mechanisms responsible for the effects of laser on tendinuos repair.
本研究旨在评估685纳米和830纳米激光在不同能量密度下对小鼠跟腱切断术后愈合过程的影响。
一些作者表明，低强度激光疗法（LLLT）能够加速损伤后肌腱组织的愈合过程，增加成纤维细胞增殖和胶原蛋白合成。然而，LLLT作用于愈合过程的机制尚未完全明确。
48只雄性小鼠被分为六个实验组：A组，跟腱切断术后用685纳米激光，剂量为3 J/cm²治疗的动物；B组，跟腱切断术后用685纳米激光，剂量为10 J/cm²治疗的动物；C组，跟腱切断术后用830纳米激光，剂量为3 J/cm²治疗的动物；D组，跟腱切断术后用830纳米激光，剂量为10 J/cm²治疗的动物；E组，损伤对照组（安慰剂治疗）；F组，未损伤标准对照组。在跟腱切断术后第13天处死动物，手术取出其肌腱，使用偏光显微镜进行定量分析，目的是通过双折射（光学延迟[OR]）测量胶原纤维的排列。
与损伤对照组相比，所有治疗组的OR值均更高。A组（685纳米，3 J/cm²）动物的胶原束排列和聚集最佳，其次是C组和B组动物，最后是D组动物。
本研究中使用的所有波长和能量密度在加速跟腱切断术后的愈合过程中均有效，特别是685纳米激光照射，剂量为3 J/cm²时。这表明存在波长组织特异性和剂量依赖性。需要进一步研究以探讨激光对肌腱修复作用的生理机制。
