Photobiomodulation therapy (PBMT) using a light-emitting diode (LED) has been employed for various photomedicine studies. The aim of this study was to determine the effects of a high-intensity red LED on the proliferation and osteogenic differentiation of human bone marrow mesenchymal stem cells (BMSCs) and the related mechanism. BMSCs were subjected to high-intensity red LED (LZ1-00R205 Deep Red LED) irradiations for 0 to 40 s with energy densities ranging from 0 to 8 J/cm2. The distance from the LED to the cell layer was 40 mm. The spot size on the target was 4 cm2. Cell proliferation was measured at 3, 24, 48, and 72 h. The effects of LED irradiation on osteogenic differentiation and mineralization were examined with a particular focus on the Wnt/β-catenin signaling pathway. The high-intensity red LED irradiations did not alter BMSC proliferation after 72 h. LED exposure of 6 J/cm2 (30 s) led to significant enhancements of osteogenic differentiation and mineralization. Additionally, the high-intensity LED irradiation induced activation of Wnt/β-catenin. The effects of the high-intensity LED irradiation on BMSC osteogenic differentiation and mineralization were suppressed by treatment with the Wnt/β-catenin inhibitor XAV939. P < 0.05 was considered significant. The results indicate that high-intensity red LED irradiation increases BMSC osteogenic differentiation and mineralization via Wnt/β-catenin activation. Therefore, short duration irradiation with a portable high-intensity LED may be used as a potential approach in hard tissue regeneration therapy.
Keywords: Bone regeneration; LED; Osteoblasts; Photobiomodulation therapy.