Effect of Continuous and Pulsed Mode of Low Power Laser Irradiation on Viability of Buccal Fat Pad Derived Adipose Stem Cells

Background and Aim: Laser photobiomodulation can be a usefulmethod in tissue engineering to enhance the proliferation and viabilityof stem cells. Laser therapy with powers less than 0.5 W can result inbiostimulation of cells and tissues. However, parameters such as power,energy density, irradiation mode (continuous or pulse mode) and stemcell type play significant roles in the results. The aim of this study was tocompare different laser settings of a 940nm laser on the viability of adiposestem cells in order to define the best settings for photobiostimulation.Methods: Adipose stem cells were isolated from the buccal fat pad. Thirdpassage the cells were seeded in 96-well plates. The cells were irradiatedat the intervals of 12 hours for three consecutive days. Irradiation wasperformed with 6 different laser settings by two modes of continuousand pulsed (50% duty cycle) and two different energy densities of 3 and6 J/cm2 and two different 0.1W and 0.3W output power using a 940nmlaser (Epic x, Biolase, USA) a non-irradiated group served as control. Thetest was repeated at 3 different times. Cell viability was evaluated by MTTassay at intervals of 24, 48 and 72 hours after the final laser irradiation.Results: After 24h the 6J/cm2, 0.3w, the pulsed group showed a 13.96%higher cell viability compared to control (P<0.01). This group also showed a 12.3% higher cell viability compared to control after 48h,however, none of the groups had statistically significant results at thistime point. 72 h after irradiation 3 J/cm2, 0.3 W, the pulsed group showed26% higher and the 3 J/cm2, 0.1 W, the pulsed group showed 22%higher viability results compared to the control which was statisticallysignificant (P<0.01). The 6 J/cm2, 0.3 W, the pulsed group also showeda 15% increase, however, this result was not statistically significant. Nostatistically significant difference was observed in the continues modeirradiated groups.Conclusion: According to the results of this study a pulsed mode ofirradiations showed better viability results on adipose stem cells.

کلیدواژه ها:

Adipose stem cells ، Low-power laser irradiation ، Laser