620Nm Red Light Promotes Celluar Viability and Mrna Expression of Collagen Type I in Bone Mesenchymal Stem Cells of Rat

Phototherapy has attracted increasing attention in recent years because numerous applications and controlled studies on the method have been reported. According to these reports, low-level red light irradiation can lead to celluar proliferation and enhance cell differentiation. The purpose of this in vitro study is to investigate the influence of red light from a light-emitting diode (LED) on rat bone mesenchymal stem cells (BMCs). The cells were seeded in 35-mm tissue culture dishes and cultured in osteogenic differentiation medium (ODM). BMSCs were irradiated once with low-level red light (620nm, 1W, 1.5 J/cm²). Then we analyzed celluar viability via methyl-tetra-zolium (MTT) assay and mRNA expression of collagen, type I, alpha 1 (COL1A1) via reverse transcriptase-polymerase chain reaction (RT-PCR). MTT assay result indicated that irradiated cells significantly proliferated. The irradiated cells had higher mRNA expression of COL1A1 than the control. In conclusion, low-level red light from LED could enhance cellular viability and osteogenic differentiation of MSCs.