Concurrent Photobiomodulation by Dual-Wavelength (655 nm and 808 nm) Laser Exposure Promotes Accelerated Wound Healing

Background: Photobiomodulation (PBM) is a noninvasive light therapy that penetrates deeper skin layers, using wavelengths such as near-infrared. Different wavelengths target specific cellular components and pathways, influencing wound healing. Light absorption by both mitochondria and light-sensitive ion channels increases intracellular reactive oxygen species (ROS) levels, thereby affecting inflammation, platelet activation, angiogenesis, tissue remodeling, and cell viability. Concurrent use of multiple wavelengths has an advantage, activating distinct pathways involved in the wound-healing process. Purpose: This in vitro study aimed to investigate the effects of concurrent PBM on fibrablasts using a dual-wavelength system (655 nm and 808 nm). The effects of concurrent PBM application at three energy densities on cell viability, intracellular ROS levels, and cell migration were assessed using two modalities: single- and triple-treatment protocols. Methods: Three different energy densities (0.5, 1, and 2 J/cm 2 ) of a dual wavelength system were used, and applications were performed using single or triple applications. Cellular responses were evaluated by assessing viability, ROS generation, and migration. Results: Concurrent PBM application at an energy density of 1 J/cm 2 showed a synergistic effect, increasing cell viability by 3%, intracellular ROS levels by 20%, and accelerating wound closure by 89% compared with the untreated group. Conclusion: Concurrent dual-wavelength PBM application may reduce treatment duration and enhance wound healing, offering a promising approach for targeting multiple layers and substructures of complex biological tissue in in vivo models and clinical applications.