Effect of Low-Level Laser Therapy on Human Adipose-Derived Stem Cells: In Vitro and In Vivo Studies

Background Low-level laser therapy (LLLT) continues to receive much attention in many clinical fields. Also, LLLT has been used to enhance the proliferation of various cell lines, including stem cells. This study investigated the effect of LLLT on human adipose-derived stem cells (ADSCs) through in vitro and in vivo studies. Methods Low-level laser irradiation of cultured ADSCs was performed using a 830 nm Ga-Al-As (gallium-aluminum- arsenide) laser. Then, proliferation of ADSCs was quantified by a cell counting kit-8. In the in vivo study, irradiated ADSCs or non-irradiated ADSCs were transplanted, and then, low-level laser irradiation of each rat was performed as per the protocol. Cell viability was quantified by immunofluorescent staining using the human mitochondria antibody. Results In the in vitro study, the laser-irradiated groups showed an increase in absorbance compared to the control group. Also, in the in vivo study, there was a significant increase in the number of human ADSCs in the laser-irradiated groups compared to the control group (p<0.001). Conclusions Our study showed that LLLT could enhance the proliferation and viability of ADSCs. The ADSCs enhanced by LLLT could be applied in various clinical fields. With the use of LLLT, the proliferation and viability of various cells can be enhanced, besides ADSCs.