Photomedicine and Laser Surgery

Objective: The aim of the present investigation was to assess morphological, cellular, and molecular effects of exposing wounded diabetic fibroblast cells to He-Ne (632.8 nm) laser irradiation at two different doses. Background Data: An alternative treatment modality for diabetic wound healing includes low-level laser therapy (LLLT). Although it's used in many countries and for many medical conditions, too many health care workers are unaware of this therapy, and there is still controversy surrounding its effectiveness. Methods: Normal human skin fibroblast cells (WS1) were used to simulate a wounded diabetic model. The effect of LLLT (632.8 nm, 5 and 16 J/cm² once a day on two non-consecutive days) was determined by analysis of cell morphology, cytotoxicity, apoptosis, and DNA damage. Results: Cells exposed to 5 J/cm² showed a higher rate of migration than cells exposed to 16 J/cm², and there was complete wound closure by day 4. Exposure of WS1 cells to 5 J/cm² on two non-consecutive days did not induce additional cytotoxicity or genetic damage, whereas exposure to 16 J/cm² did. There was a significant increase in apoptosis in exposed cells as compared to unexposed cells. Conclusion: Based on cellular morphology, exposure to 5 J/cm² was stimulatory to cellular migration, whereas exposure to 16 J/cm² was inhibitory. Exposure to 16 J/cm² induced genetic damage on WS1 cells when exposed to a He-Ne laser in vitro, whereas exposure to 5 J/cm² did not induce any additional damage.