Fully Functional Skin Grown From Stem Cells Could Double As Skin Graft Replacement, Hair Loss Cure
If there’s one thing skin can do well, it’s grow. Each month our body replaces its skin, nearly 19 million skin cells per inch — a feat that’s been far less successful in the lab. However, the days of lab-grown skin may not be too far off: Recently, a team of Japanese scientists not only grew fully functional skin tissue, but also transplanted it successfully onto living organisms.
Though the technique has only been tested on mice so far, the team predicts it could one day revolutionize treatments for burn victims, or other patients that have suffered catastrophic skin damage. On a less gruesome note, the team says it may also be useful in treating a more common condition: baldness.
The study, published online in Science Advances, involved researchers from the Riken Center for Developmental Biology and Tokyo University of Science, among other Japanese institutions. The researchers’ first step was to transform cells from the gums of mice into induced pluripotent stem cells, or adult cells that have been genetically reprogrammed back into an embryonic stem cell state. This is done by forcing the cells to express genes associated with embryonic stem cells. Once transformed into stem cells, they can then be manipulated to become any type of cell in the body.
Next, the team placed the stem cells into a petri dish, where they added the molecule Wnt10b, which coaxed the stem cells to form into clusters that resembled a developing embryo. These clusters were then transplanted into mice bred without a fully functional immune system, which ensured that their bodies did not reject the transplant. Here, they underwent cell differentiation, the process by which unspecialized cells become specialized. In this case, they were becoming skin cells, and once the process had begun, the cells were transplanted again onto the skin of new mice, where they made normal connections with surrounding nerve and muscle tissue to become fully functional skin.
Skin is one of the largest and most important organs in the human body, yet it’s also one of the most difficult to treat when it’s damaged. Current treatment options involve painful skin grafts or barely functional artificial skin. According to the new study, however, being able to grow skin in the lab will account for more than just skin's use in protecting our inner bodies. The lab-grown skin also showed the ability to develop hair follicles and sweat glands, which play a role in controlling body temperature and keeping the skin moisturized — it's in these areas that skin repair has often fallen short.
"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,” lead researcher, Takashi Tsuji of the RIKEN Center for Developmental Biology,said in a recent statement. “With this new technique, we have successfully grown skin that replicates the function of normal tissue.”
In addition to revolutionizing skin repair, the technique may also help those with certain types of hair loss. The study noted that using Wnet10b on the stem cells resulted in the production of a higher number of hair follicles than previous attempts at growing skin. Within two weeks of receiving the transplanted skin, the mice began to grow hair. Dr. Seth Orlow, chair of dermatology at NYU School of Medicine in New York City, told U.S. News Health that this feature of the lab-grown skin could be manipulated to help patients with both alopecia and pattern baldness.
“In theory, we may eventually be able to create structures like hair follicles and other skin glands that could be transplanted back to people who need them,” Orlow told U.S. Health News.
According to The Washington Post, the technique is still about five to 10 years away from being safe and effective enough to be used on humans. But with about 95 percent of men and 50 percent of women experiencing some degree of baldness over the course of their lives, it’s a safe bet that there will be no shortage of eager customers ready to get their hair back when the treatment is approved for use in doctors’ offices.
Source: Takagi R, Ishimaru J, Sugawara A, et al. Bioengineering a 3D integumentary organ system from iPS cells using an in vivo transplantation model. Science Advances . 2016