The effects of 620nm noncoherent red light irradiation on proliferation and osteogenic differentiation of rat osteoblasts / 中华物理医学与康复杂志

ABSTRACT

Objective To investigate the effects of 620nm noncoherent red light emitted from light-emitting diode (LED) on proliferation and osteogenic differentiation of rat osteoblasts.Methods Osteoblasts were isolated from SD rat and cultured in vitro.The LED was placed at 2cm above the cell layer.Cells were divided into four groups and each group was irradiated for 0s, 150s, 300s and 600s at energy dose of 0, 1, 2, and 4J/cm2, respectively.Cells were irradiated once every day.Cellular proliferation activities were evaluated by using cell counting kit-8 ( CCK-8 ) at 2nd and 4th d.The alkaline phosphatase (ALP) ratio activity was evaluated by alkaline phosphatase activity kit at the 9th d, and expressions of osteoblast master genes ( Collα1, Bglap and Runx2) were monitored as indicators of osteoblast differentiation by reverse transcription-polymerase chain reaction (RT-PCR) technique.Results In the group irradiated with 1 and 2 J/cm2 proliferation activities of osteoblasts enhanced significantly compared with the control group at the 4th d ( P < 0.05 ).In the group irradiated with 4 J/cm2 ALP ratio activity elevated significantly compared with the control group at the 9th d ( P <0.05 ).In the group of red light irradiation expressions of Bglap and Runx2 enhanced significantly.Conclusion The 620nm nonconherent red light emitted from LED can promote proliferation of osteoblasts and enhance osteogenic differentiation significantly.