The Effect of Low Level Laser Irradiation on Human Embryonic Stem Cells

Introduction: different effects of low level laser irradiation (llli)on various cell types have already been demonstrated. however, itseffects on embryonic stem cells have not yet been shown. thepresent study evaluates the morphological and immunocytochemicaleffects of llli on human embryonic stem cell (hesc) colonies.material and methods: equal-sized pieces of hesc line (royanh1) were irradiated with a single dose of 830-nm ga-ai-as diodelaser (3, 5, and 8 [ern, 30mw) and cultured on mouse embryonicfibroblasts. the morphology of the colonies was evaluatedqualitatively by observation under an inverted microscope (grades a,b, c, and d exhibited 0-30%, 30-50%, 50-80%, and 80-100%differentiation, respectively). the stemness area was assessed byexpression of surface antigens using anti-tra-1-60 and anti-tra-1-81.results: our data demonstrated a dose-dependent stimulatoryeffect of llli on hesc differentiation. two doses of 5 and 8jcm-2induced statistically significant differentiation (grades c and d).conclusions: these data showed that llli influenced hescdifferentiation, which might be used for cell therapy aftertransplantation.