Photobiomodulation: Cellular, molecular, and clinical aspects

Photobiomodulation (PBM) is a noninvasive photonic-based therapy, capable of dealing with immune-inflammatory, neurological, and musculoskeletal disorders, as well as healing oral and chronic skin wounds. During PBM light is applied at a specific wavelength, either in the visible or near-infrared (NIR) ranges. Photophysical and photochemical processes might stimulate or inhibit various biological processes, depending on the target tissue, the wavelength of light, irradiance, fluence, repetition rate (pulse frequency), spot size, optical data of the tissue to be irradiated and treatment regimen. There are several randomized clinical studies demonstrating the PBM benefits as main or adjuvant therapies. Of importance to this review, there is a large piece of evidence in the management of skin or venous ulcers, and diabetic foot. In this review, the PBM´s efficacy as adjuvant therapy to deal with chronic human ulcers were discussed concerning the photophysical parameters and clinical aspects. Beside, we overview the state-of-the-art regarding the cellular and molecular modulatory mechanisms photoactivated by red and NIR light.