Molecular hydrogen promotes wound healing by inducing early extracellular matrix deposition and epidermal stem cell proliferation

Background: Despite progress in developing wound care strategies, there is currently no treatment that promotes the self-tissue repair capabilities. H 2 has been shown to effectively protect cells and tissues from oxidative and inflammatory damage. While comprehensive effects and how H 2 functions in wound healing are still obscure. Methods Here, we established a cutaneous aseptic wound model and applied a high concentration of H 2 (66% H 2 ) in a treatment chamber. Molecular mechanisms and the effects of healing were evaluated by gene functional enrichment analysis, blood perfusion/oxygen detection assay, in vitro tube formation assay, enzyme-linked immunosorbent assay, immunofluorescent staining, non-targeted metabonomic analysis, flow cytometry, transmission electron microscope, and live-cell imaging. Results We revealed that a high concentration of H 2 (66% H 2 ) greatly increased the healing rate (3 times higher than the control group) on day 11 post wounding. The effect was not dependent on O 2 or anti-reactive oxygen species functions. Histological and cellular experiments proved the fast re-epithelialization in the H 2 group. Extracellular matrix components early (3 days post wounding) deposition were found in the H 2 group of the proximal wound, especially for the dermal col-I, epidermal col-III, and dermis-epidermis-junction col-XVII. H 2 accelerated early autologous epidermal stem cell proliferation (1–2 days in advance) and then differentiation into myoepithelial cells. Other beneficial outcomes include sustained moist healing, greater vascularization, less T-helper-1 and T-helper-17 cell-related systemic inflammation, and better tissue remodelling. Conclusion We have discovered a novel pattern of wound healing induced by molecular hydrogen treatment. These H 2 -induced multiple advantages in healing may be related to the enhancement of cell viability in various cells and the maintenance of mitochondrial functions at a basic level in the biological processes of life.