830-nm irradiation increases the wound tensile strength in a diabetic murine model

Background and Objective: The purpose of this study was to investigate the effects of low-power laser irradiation on wound healing in genetic diabetes . Study Design/Materials and Methods: Female C57BL/Ksj/db/db mice received 2 dorsal 1 cm full-thickness incisions and laser irradiation (830 nm, 79 mW/c m(2), 5.0 J/cm(2)/wound). Daily low-level laser therapy (LLLT) occurred ove r 0-4 days, 3-7 days, or nonirradiated. On sacrifice at 11 or 23 days, woun ds were excised, and tensile strengths were measured and standardized. Resu lts: Nontreated diabetic wound tensile strength was 0.77 +/- 0.22 g/mm(2) a nd 1.51 +/- 0.13 g/mm(2) at II and 23 days. After LLLT, over 0-4 days tensi le strength was 1.15 +/- 0.14 g/mm(2) and 2.45 +/- 0.29 g/mm(2) (P = 0.0019 ). Higher tensile strength at 23 days occurred in the 3- to 7-day group (2. 72 +/- 0.56 g/mm(2) LLLT vs. 1.51 +/- 0.13 g/mm(2) nontreated; P less than or equal to 0.01). Conclusion: Low-power laser irradiation at 830 nm significantly enhances cu taneous wound tensile strength in a murine diabetic model. Further investig ation of the mechanism of LLLT in primary wound healing is warranted. (C) 2 001 Wiley-Liss, Inc.