Effect of low-level laser therapy on types I and III collagen and inflammatory cells in rats with induced third-degree burns

Lasers Med Sci. 2014 Jan;29(1):313-9. doi: 10.1007/s10103-013-1341-2. Epub 2013 May 16.


Low-level laser therapy (LLLT) has been increasingly used to accelerate wound healing in third-degree burns. This study investigated the effects of lasers on the tissue repair process of third-degree burns. Burns were produced on the backs of male Wistar rats. The animals were divided into four groups (n = 12): control, injury, LLLT 3 J/cm(2), and LLLT 4 J/cm(2). Each group was further divided into two subgroups; the rats in one subgroup were killed on day 8 and those in the other, on day 16 after injury. The animals in LLLT 3 J/cm(2) and LLLT 4 J/cm(2) were irradiated 1 h after injury, and irradiation was repeated every 48 h. Laser (660 nm, 35 mW) treatment at fluences of 3 and 4 J/cm(2) were used. After killing the rats, tissue fragments from the burnt area were removed for histological analysis. The LLLT-treated groups showed a significant decrease (p <0.05) in the number of inflammatory cells and increased collagen deposition compared to the injury group. Laser irradiation (both 3 and 4 J/cm(2)) resulted in reduction in the inflammatory process and improved collagen deposition, thereby ameliorating the healing of third-degree burns.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Animals
  • Burns / metabolism*
  • Burns / pathology
  • Burns / radiotherapy*
  • Collagen Type I / metabolism*
  • Collagen Type III / metabolism*
  • Disease Models, Animal
  • Inflammation / pathology
  • Inflammation / radiotherapy
  • Lasers, Semiconductor / therapeutic use
  • Low-Level Light Therapy / methods*
  • Male
  • Microscopy, Polarization
  • Rats
  • Rats, Wistar
  • Time Factors
  • Wound Healing / radiation effects


  • Collagen Type I
  • Collagen Type III