Researchers from the Netherlands have discovered that cells from the non-viable tissue that remains after burn injuries, which are normally removed by debridement, to prevent infection, are a potential source of mesenchymal cells that can be used for tissue engineering. In this study, the research team of Magda Ulrich compared cells isolated from burn eschars (dry scabs or sloughs formed on the skin as a result of a burn or by the action of a corrosive or caustic substance) with fat-derived stem cells and dermal fibroblasts, and determined how well they conform to those criteria established for multipotent mesenchymal stromal cells.
According the Dr. Ulrich, who is member of the Association of Dutch Burn Centers in the Netherlands: “In this study we used mouse models to investigate whether eschar-derived cells fulfill all the criteria for multipotent mesenchymal stromal cells as formulated by the International Society for Cellular Therapy (ISCT). The study also assessed the differentiation potential of MSCs isolated from normal skin tissue and adipose tissue and compared them to cells derived from burn eschar.”
Burn treatment advances have increased the percentage of patients who survive severe burn injuries. This growing survival rate has also increased the number of people who are left with burn scars, and these scars cause skin problems, such as contracture (shortening and hardening of muscles, tendons, or other tissues that leads to deformity and rigidity of joints), and the social and psychological aspects of disfigurement.
Tissue engineering attempts to rebuild the skin are some of the most promising approaches to addressing these problems. Unfortunately, two shortcomings with this approach include finding a viable source of stem cells for the therapy and designing the scaffold that produces a suitable microenvironment to guide the stem cells toward those behaviors that engender tissue regeneration.
“The choice of cells for skin tissue engineering is vital to the outcome of the healing process,” Ulrich said. “This study used mouse models and eschar tissues excised between 11 and 26 days after burn injury. The delay allowed time for partial thickness burns to heal, a process that is a regular treatment option in the Netherlands and rest of Europe.”
Since elevated levels of MSCs have been detected in the blood of burn victims, Ulrich and her co-workers suspected that shortly after being burned, the severely damaged tissues attract stem cells from the surrounding tissues,.
“MSCs can only be beneficial to tissue regeneration if they differentiate into types locally required in the wound environment,” Ulrich said. “We concluded that eschar-derived MSCs represent a population of multipotent stem cells. The origin of the cells remains unclear, but their resemblance to adipose-derived stem cells could be cause for speculation that in deep burns the subcutaneous adipose tissue might be an important stem cell source for wound healing.”
Further work is needed to properly identify the origins of the stem cells found in the burn eschar, and how their function is influenced by the wound environment.