If you are exposed to high local doses of radiation, your skin will burn and undergo very slow healing. Your skin will also experience a great deal of cell death, and high levels of cell death within a tissue cause a condition called necrosis. High levels of local radiation, which cause painful necrosis, slow healing and a delayed outcome, are characteristics of “cutaneous radiation syndrome.”
Recently, work on cutaneous therapeutic management of patients with cutaneous radiation syndrome has strongly suggested that such burn patients would benefit from stem cell treatments with mesenchymal stem cells. A paper from the laboratory of Michel Drouet, who is a member of the Radiology Department at the Institut de Recherche Biomédicale des Armées in La Tronche, France has examined such a treatment strategy in pigs.
Diane Riccobono and her colleagues compared the effectiveness of an animal’s own stem cells with the effectiveness of borrowed stem cells from another unrelated animal. They used minipigs for these experiments, and the animals were exposed to about 50 Grays of radiation, which is about the radiation dose someone would receive for radiation therapy. The animals were divided into three groups.
One group was engrafted with their own fat-based mesenchymal stem cell (5 animals in this group). The second group was engrafted with fat-based mesenchymal stem cells from another animals (5 animals in this group too). Animals received fat-based mesenchymal stem cells four times after receiving their dose of radiation. A third group consisting of eight animals received culture media but no cells.
All the pigs were examined and scored according to the severity of their wounds. The control animals showed local inflammatory that led to persistent painful necrosis. Since this display is very similar to what is observed in human patients with cutaneous radiation syndrome, it gave Riccobono and her colleagues a great deal of confidence that this animal model nicely mimics the clinical progression of this disease in human patients. Also, the clinical outcome was not significantly different in the animals treated with fat-based mesenchymal stem cells from another unrelated animal. These animals showed skin healing without necrosis, and the animals suffered from uncontrollable pain, much like the controls. However, in the animals engrafted with fat-based stem cells from their own bodies, the radiation wounds healed without necrosis. Furthermore, healing also did not progress to uncontrollable pain.
This study seems to show that stem cell grafting with fat-based stem cells a patient’s own body improves healing in patients with cutaneous radiation syndrome. However, fat-based mesenchymal stem cells from unrelated animals do not facilitate such healing. Can manipulation of allogeneic stem cells improve their therapeutic potential? Only further work will tell.
See Riccobono D, Agay D, Scherthan H, Forcheron F, Vivier M, Ballester B, Meineke V, Drouet M.., Application of adipocyte-derived stem cells in treatment of cutaneous radiation syndrome. Health Phys. 2012 Aug;103(2):120-6.