Skin burn injury is marked by local inflammation and cutaneous necrosis that may extend to the deep subcutaneous structures.Today, treatment is surgical excision, epidermis autograft and flap with sometimes bad results.It has been suggested that Mesenchymal Stem Cells (MSC) therapy could be used in order to treat numerous tissue lesions.We have performed a novel therapeutic approach of local radiation-induced burns by using local autologous MSC therapy combined to surgery and epidermis autograft.For this purpose,autologous bone marrow cells were collected from the unexposed iliac crest.For GMP production, MSC were expanded in a closed system (MacoPharma partnership) containing an innovative serum free medium supplemented with human platelet lysate as previously described (Doucet et al., J.Cell Physiol., 2005).Quality control assays evidenced that expanded cell population retained typical MSC characteristics and did not exhibit chromosomal abnormalities.As previously demonstrated, MSC produced many cytokines and growth factors which could have a critical role in improving the healing process by counteracting the local inflammatory waves and by promoting the autologous skin engraftment.We believe that MSC act as drug cells delivering in situ in the lesion growth factors which contribute to the healing of the lesion.We have also demonstrated that after in vitro cell activation, the conditioned medium of MSC exhibited a similar effect on wound healing than that obtained with freshly expanded MSC.In case of karyotypic abnormalities occurring after in vitro MSC expansion, the use of MSC conditioned medium could be considered as a relevant alternative of MSC therapy.