title: Wound healing efficacy of a 660-nm diode laser in a rat incisional wound model.
abstract: This study aimed to elucidate the optimum usage parameters of low reactive-level laser therapy (LLLT) in a rat incisional wound model. In Sprague-Dawley rats, surgical wounds of 15-mm length were made in the dorsal thoracic region. They were divided into groups to receive 660-nm diode laser irradiation 24 h after surgery at an energy density of 0 (control), 1, 5, or 10 J/cm2. Tissue sections collected on postoperative day 3 were stained with hematoxylin-eosin and an antibody for ED1 to determine the number of macrophages around the wound. Samples collected on day 7 were stained with hematoxylin-eosin and observed via polarized light microscopy to measure the area occupied by collagen fibers around the wound; day 7 skin specimens were also subjected to mechanical testing to evaluate tensile strength. On postoperative day 3, the numbers of macrophages around the wound were significantly lower in the groups receiving 1 and 5 J/cm2irradiation, compared to the control and 10 J/cm2irradiation groups (p < 0.01). The area occupied by collagen fibers in day 7 was largest in 5 J/cm2group, followed by 1 J/cm2group, although this difference was not significant. The day 7 tensile test demonstrated significantly greater rupture strength in healing tissues from 1 and 5 J/cm2irradiation groups, compared to the control group (p < 0.05). Thus, LLLT with a 660-nm diode laser with energy density of 1 and 5 J/cm2enhanced wound healing in a rat incisional wound model. However, a higher radiation energy density yielded no significant enhancement.
authors: Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-0062, Japan.
authors: Ryoichi
authors: R
authors: Suzuki
authors: Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-0062, Japan. takakuda.mech@tmd.ac.jp.
authors: Kazuo
authors: http://orcid.org/0000-0001-8117-6793
authors: K
authors: Takakuda
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D054023:Lasers, Semiconductor; D008264:Macrophages / Q000378:metabolism; D008297:Male; D017207:Rats, Sprague-Dawley; D012867:Skin / Q000473:pathology* / Q000528:radiation effects; D013718:Tensile Strength; D014945:Wound Healing / Q000528:radiation effects*
keywords: Collagenous tissues; Diode laser; Low reactive-level laser therapy; Macrophage; Tensile strength; Wound healing