Blue LED light photobiomodulation in cultured human fibroblasts and keratinocytes cell line

In the last decade PhotoBioModulation therapy (PBM) gained importance in clinical practice, thanks to the technological development of low cost lights sources in a broad wavelength range. In wound management, PBM has been listed as physical therapy and blue light has been used in case of insufficient healing, as in chronic and hard-to-heal wounds. In our previous study in in vivo model, we demonstrated that blue light (410-430 nm) can modulate fibroblasts activity in superficial wounds. Here, we present a study about the effects of blue light (3.43-6.87-13.7-20.6-30.9 and 41.2 J/cm doses applied, 410-430 nm, 0.69 W/cm power density) on cellular metabolism, proliferation and viability of human fibroblasts obtained from keloid and perilesional tissues, compared with fibroblasts isolated from healthy skin. Excessive healing, where fibrotic tissue is formed, is an aberration in wound healing, denoted by keloids and hypertrophic scars. In the study, electrophysiology was used to investigate the effects on membrane currents while Raman spectroscopy revealed the mitochondrial Cytochrome C oxidase dependence on blue light irradiation. Also, the keratinocytes cell line was tested and co-cultures were prepared to perform scratch test assays. Finally, a simple model to study the effectiveness of light irradiation in cells in the depth tissue, was optimized using a dermal substitute. Overall, these data demonstrate that PBM can be used as an innovative and minimally-invasive approach in wound management not only in case of insufficient healing, but also in skin fibrosis, in association with standard treatments.