Experimental evidence on photobiomodulation induced by short wavelengths blue LED light

Skin serves as a vital component for thermoregulation and acts as a barrier against external threats. Wounds compromise the integrity of the skin and can lead to serious pathologies. Therefore, effective treatment of skin wounds is imperative, particularly in cases of chronic wounds or in individuals with comorbidities. Fibroblast cells play a crucial role in wound healing and represent a model for in vitro studies on photobiomodulation (PBM). The use of blue LED light in PBM has been shown to be effective in wound management, although the exact mechanism of action is still unclear. Several studies have investigated this, identifying specific target molecules, including Cytochrome C oxidase. Mitochondria appear to be a key target for blue light irradiation. To investigate this further, primary cultures of human dermal fibroblasts were established and a blue LED light device (410 to 430nm, 1W optical emission power) was used. A single application administered three doses of blue light (4, 21, 41 J/cm2). Mitochondrial morphology was observed before and after irradiation using electron microscopy. Subsequent studies will aim to determine if changes in morphology correspond to alterations in function. Previous in vitro findings indicated enhanced cell viability, proliferation, and outward currents at the lower fluence (4 J/cm2). Conversely, the higher dose (41 J/cm2) reduced cell viability. Here, we present preliminary results on the impact of 4 J/cm2 blue LED light on outward currents in fibroblasts. Our results highlight the PBM properties of short-wavelength blue LED light.