Hypoxia-preconditioned gingiva-derived mesenchymal stem cell-conditioned medium accelerates burn wound healing

Burn injuries remain a major clinical challenge due to the complex wound microenvironment and limited donor skin availability. Gingival mesenchymal stem cells (GMSCs), which are easily accessible and possess strong immunomodulatory and regenerative capacities, represent a promising therapeutic resource. Increasing attention has focused on the use of GMSC-derived conditioned medium (CM) as a cell-free alternative, particularly when its efficacy is enhanced through hypoxic preconditioning. In this study, human-derived GMSC-conditioned medium was used to examine the effects of hypoxia-preconditioned GMSC-CM (HP-GMSC-CM) on burn wound healing in vitro and in vivo. In HaCaT keratinocyte cultures, HP-GMSC-CM significantly promoted scratch wound closure and enhanced cell migration in Transwell assays, accompanied by upregulated expression of LAMC2 and COL4A1. In M1-polarized macrophages, HP-GMSC-CM markedly suppressed secretion of the pro-inflammatory cytokines TNF-α and IL-1β. In a murine burn model, treatment with HP-GMSC-CM accelerated wound closure and increased the expression of epithelial marker Pan-CK and extracellular matrix protein TNC. Mechanistic inhibition with LY294002 suggested that these therapeutic effects are mediated, at least in part, through PI3K/AKT-associated signaling. Collectively, these findings suggest that hypoxia-preconditioned GMSC-derived CM may serve as an effective cell-free therapeutic strategy for promoting burn wound repair and support its potential translational applicability despite the use of a xenogeneic experimental model.