This could be revolutionary for burn victims and others in need of skin transplants.
In the recent years, research into bioengineered tissues has led scientists to important achievements concerning transplants. In the area of skin tissue, scientists have been able to successfully grow epithelial cells — the layer of cells that line hollow organs and glands — into implantable sheets, but they lacked key features, like oil-secreting and sweat glands, which would enable them to function like normal skin tissue.
However, researchers from the RIKEN Center for Developmental Biology (CDB) in Japan along with collaborators from Tokyo University of Science and other Japanese institutions, may have changed the game.
They’ve successfully grown complex skin tissue in the laboratory, complete with hair follicles and sebaceous glands, which are small glands in the skin that secrete oil to lubricate the skin and hair.
Amazingly, the scientists were able to implant the three-dimensional tissues into living mice, and the tissues formed proper connections with other bodily organ systems like nerves and muscle fibers.
How did they pull it off? The researchers report in the journal Science Advances that they took cells from mouse gums and used chemicals to reprogram them into stem cells with the potential to become any kind of cell. This process is called "induced pluripotency" and relies on the fact that every cell in your body contains the genetic blueprints for all cell types, from blood cells to brain cells or even skin cells.
Then, in lab culture, the induced pluripotent stem cells developed into what is called an embryoid body, which is a 3D clump of cells that partially resembles the developing embryo in an actual body, according to the press release.
The scientists implanted multiple embryoid bodies into immunodeficient mice, and they gradually transformed into differentiated tissue, meaning they organized into communities of cells that work together to carry out a specific function.
After the tissue differentiated, the scientists transplanted the tissues into the skin tissue of other mice, and they developed normally as integumentary tissue — the tissue between the outer and inner skin that manages the skin’s hair shaft eruption and oil excretion.
Perhaps the most important finding was that, through this technique, the tissues made normal connections with the surrounding nerve and muscle tissues.
"Up until now, artificial skin development has been hampered by the fact that the skin lacked the important organs, such as hair follicles and exocrine glands, which allow the skin to play its important role in regulation,” said study lead Takashi Tsuji of the RIKEN Center for Developmental Biology.
“With this new technique, we have successfully grown skin that replicates the function of normal tissue,” he continued. “We are coming ever closer to the dream of being able to recreate actual organs in the lab for transplantation, and also believe that tissue grown through this method could be used as an alternative to animal testing of chemicals."
This work could be a revolutionary step in creating functional skin transplants for burn victims and other patients who require new skin.