Blue light induced modulation in the early phase of wound healing

Blue LED light (420 nm) has successfully been used to induce hemostasis through a photo-thermo-coagulation process: light absorption by hemoglobin triggers a local temperature increase, leading to a coagulation effect. Besides hemoglobin, there are other macromolecules, such as cytochromes, that are able to absorb blue light: after irradiation, these ubiquitous cellular components can trigger one or more intracellular pathway that modulates the healing process, in combination with the coagulation effect. The aim of this study is to investigate the molecular effects of 30s treatment with a Blue LED device in two different murine model wounds. In the first model we studied a superficial wound, and in particular the inflammatory response by an immunohistochemical and morphological analysis of the many cellular types involved in this phase of the healing process. The second model is a full-thickness wound: a customized ELISA kit enabled to study EGF, bFGF, VEGF, TNF-alpha, MMP-2 and PRO-MMP-9 at different postoperative time points (1, 3, 6, 9, 24 hours and 7 and 14 days after the treatment). A modulation of these parameters was evidenced in the early phase of the wound healing process, while at longer follow up times no differences are pointed out.