Effect of low-intensity laser irradiation (660 nm) on a radiation-impaired wound-healing model in murine skin

• Published in: Lasers in surgery and medicine Vol. 26; no. 1; pp. 41 - 47
• Main Authors: Walker, Mark D., Rumpf, Shelli, Baxter, G. David, Hirst, David G., Lowe, Andrea S.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 2000; Wiley-Liss
• Subjects: Animals; Biological and medical sciences; Dermatologic Surgical Procedures; full-thickness skin excision; laser therapy; Lasers; Male; Medical sciences; Mice; Mice, Inbred BALB C; Radiation Dosage; Skin - radiation effects; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Technology. Biomaterials. Equipments; Time Factors; Wound Healing - radiation effects; Treatment efficiency; Rodentia; Photoinduced effect; Low intensity; Laser irradiation; Energy level; Wound; Vertebrata; Mammalia; Mouse; Animal; Biological effect; Derm; Cicatrization
• ISSN: 0196-8092; 1096-9101
• DOI: 10.1002/(SICI)1096-9101(2000)26:1<41::AID-LSM7>3.0.CO;2-M

Background and Objective
The use of low‐intensity laser therapy (LILT) as a therapeutic modality has become popular in a variety of clinical applications including the promotion of wound repair. Although the clinical evidence base for such application remains sparse, recent studies have demonstrated a number of quantifiable photobiological effects associated with such therapy. In the present study, the effect of laser irradiation at various radiant exposures on a radiation‐impaired wound‐healing model in murine skin was investigated.
Study Design/Materials and Methods
The study included two phases; in phase one, male Balb/c mice (n = 36; age‐matched at 10 weeks) were randomly allocated to three experimental groups (n = 12, each group). In all groups, a well‐defined area on the dorsum was exposed to 20 Gy x‐rays. Seventy‐two hours postirradiation, all mice were anaesthetised and a 7 × 7 mm area wound was made on the dorsum. All wounds were videotaped alongside a marker scale (three times weekly) until closure was complete. In groups 2 and 3, mice were treated with laser irradiation (0.5 and 1.5 J/cm2, respectively) three times weekly by using a 660‐nm GaAlAs laser unit (5 kHz; 15 mW; Omega Laser Systems, London, UK). Wound areas were then calculated by using an image analysis system (Fenestra 2.1), and results were analyzed by using repeated measures and one‐factor analysis of variance statistical tests. In phase two, two experimental groups were included (n = 12 each group); the protocol was identical to that described for phase 1; however, mice in group 2 were treated with a radiant exposure of 4 J/cm2.
Results
Results from this investigation demonstrated that treatment with 0.5, 1.5. and 4 J/cm2 had no beneficial effect on the rate of wound closure (P > 0.05).
Conclusion
These findings provide little evidence of the putative stimulatory effects of LILT in vivo at the parameters investigated. Lasers Surg. Med. 26:41–47, 2000. © 2000 Wiley‐Liss, Inc.