Advancement of Photobiomodulation Therapy Using 680 and 850 nm Light‐Emitting Diodes for the Differentiation of Human Brain Endothelial Cells

Abstract Photobiomodulation (PBM) has emerged as a promising therapeutic approach for modulating cellular behavior and improving health outcomes, particularly in the context of vascular health. Despite growing interest in PBM, a key gap exists in understanding how specific wavelengths, such as 680 and 850 nm, affect endothelial cell function. While light's general effects on cell viability and mitochondrial function are known, the precise mechanisms underlying PBM's influence on endothelial cells remain unclear, limiting the optimization of PBM protocols for vascular dysfunction. In this study, the effects of PBM on endothelial cells are investigated using the light peaked at 680 and 850 nm with full width at half maximum (FWHM) about 17.5 and 25.1 nm, respectively, assessing cell viability, mitochondrial activity, reactive oxygen species (ROS) production, calcium flux (Ca 2+ ), and transepithelial electrical resistance (TEER). These findings demonstrate that PBM exposure enhances mitochondrial function, reduces oxidative stress, and modulates calcium signaling, all of which contribute to changes in endothelial barrier integrity. These results highlight the potential of PBM as a novel therapeutic strategy for enhancing endothelial cell function and addressing endothelial dysfunction, opening new avenues for future research and clinical applications in vascular health.