Epithelial cell-enhanced metabolism by low-level laser therapy and epidermal growth factor

Reepithelialization and wound closure are the desired outcome for several ulcerative conditions. Such resolution reduces the possibility of wound contamination and maintenance of the injury and improves the reestablishment of tissue morphology and functions. Investigators are seeking adjuvant therapies that can accelerate wound healing and are developing new strategies for clinical applications. This study compared the effects of epidermal growth factor (EGF) application and low-level laser therapy (LLLT) on cultured epithelial cells. Cells were seeded in 24-well plates. After a 24-h incubation, the epithelial cells were either treated with EGF (100 mu M in serum-free DMEM for 72 h) or subjected to LLLT (780 nm, 25 mW, 0.5, 1.5, and 3 J/cm(2)) by three applications every 24 h. Seventy-two hours after cells were treated with EGF or LLLT, cell migration, viability, proliferation, and collagen synthesis were assessed. Cells treated with EGF showed increased cell viability, proliferation, and collagen synthesis compared with those cells that received no treatment. LLLT enhanced cell migration; however, no significant effects of laser irradiation on other cell functions were observed. Comparison of both therapies demonstrated that EGF and LLLT enhanced specific epithelial cell activities related to wound healing.