Alterations in cell migration and cell viability of wounded human skin fibroblasts following visible red light exposure

The present study intended to examine the effect of visible red light on structural and cellular parameters on wounded skin fibroblast cells. To achieve the stated objective, uniform scratch was created on confluent monolayered human skin fibroblast cells, and were exposed to single dose of He-Ne laser (15 mm spot, 6.6808 mWcm^-2) at 1, 2, 3, 4, 5, 6 and 7 Jcm^-2 in the presence and absence of 10% fetal bovine serum (FBS). Beam profile measurements of the expanded laser beam were conducted to ensure the beam uniformity. The influence of laser dose on the change in temperature was recorded using sensitive temperature probe. Additionally, following laser exposure cell migration and cell survival were documented at different time intervals on wounded human skin fibroblast cells grown in vitro. Beam profile measurements indicated more or less uniform power distribution over the whole beam area. Temperature monitoring of sham irradiated control and laser treatment groups displayed negligible temperature change indicating the absence of thermal effect at the tested laser doses. In the absence of 10% FBS, single exposure of different laser doses failed to produce any significant effects on cell migration or cell survival. However, in the presence of serum single exposure of 5 J/cm² on wounded skin fibroblasts significantly enhanced the cell migration (P<0.05) compared to the other tested doses (1, 2, 3, 4, 6 and 7 J/cm²) and sham irradiated controls. In conclusion, the LLLT acts by improving cell migration and cell proliferation to produce measurable changes in wounded fibroblast cells.