“Skin grafting is a critical procedure for treating severe skin wounds. However, harvesting enough donor skin for extensive wounds is challenging, and creating artificial skin substitutes with hair follicles and sweat glands that can integrate with deep wounds has not been successful. Now, researchers from Japan have developed a new method to “grow your own” donor skin, potentially improving the success of skin grafts.
In a study published in Nature Communications, researchers from Tokyo Medical and Dental University (TMDU) demonstrated that growing donor skin in another species produces surprisingly robust and functional skin grafts.
The gold standard for treating burn wounds is autologous skin grafting, where skin sheets containing both the epidermis (outer layer) and dermis (deeper layer) are transplanted from other parts of the patient’s body to the wounded area. For large wounds, harvesting enough skin from limited donor sites is difficult. Split-thickness grafts, which contain mostly epidermis and some dermis, can cover larger areas but lack features like hair and sweat glands and are prone to shrinkage and scarring.
“As alternatives to autologous skin grafts, artificial skin substitutes, including cultured epidermis and reconstituted skins, have been developed,” says Dr. Hisato Nagano, lead author of the study. “However, these options are inferior as cultured epidermis is only suitable for shallow wounds, and reconstituted skins have a low engraftment rate.”
To demonstrate a new method for producing autologous skin grafts, researchers introduced a mutation into mouse fetuses that prevented them from growing mature epidermis. These fetuses were injected with mouse stem cells and allowed to develop normally until birth, when their skin growth was analyzed.
“The results were very surprising,” explains Dr. Naoaki Mizuno, corresponding author. “The chimeric mice were born with large patches of skin derived from the injected cells, which survived up to 3 months when grafted onto mature mice and even grew fur.”
Injecting the same mutated mouse embryos with human skin cells yielded similar results: as the mice developed in utero, they grew sheets of human skin that mimicked the structure and organization of mature epidermis.
“Our findings suggest that semi-autologous skin grafts containing hair follicles and other skin appendages can be generated in vivo and successfully engrafted,” says Dr. Hiromitsu Nakauchi, senior author.
Since mouse embryos can only grow small amounts of skin, the next step is to scale up the process to larger animals with longer gestation periods to generate large human skin grafts. This approach, focused on generating only skin tissue, could help avoid ethical concerns about using human-animal chimeras for organ production.”
Source link