Nature: New technology to renewable hair, or treatment of hair loss from the root cause

1975, MIT's Rheinwald and Green solved the problem of large-scale in-body culture of skin cells, and the research and production of skin substitutes developed. However, rebuilding skin with hair follicles and glands in cultures and bioengineering grafts remains an unresolved biomedical challenge.Forty-five years later, a new study published by Nature promises to push tissue dermatology into a new phase of development and pave the way for addressing the "world-class medical challenge" of hair loss.On June 4, 2020, a team led by Karl R. Koehler of Indiana University School of Medicine, based on research in stem cell biology and hair follicle development, developed an organ culture system that produces fully close to human skin from human pluripotent stem cells, a method that has been successful in helping hairless mice grow hair.The skin is divided into the skin and dermat skin, both of which come from different cell types in early embryos. By gradually regulating the signaling path path of transformational growth factors β (TGF beta) and fibroblast growth factors (FGF), the researchers encouraged erythrmmune stem cells to produce complex skin with both components: first, protein 4 (BMP) using bone morphology. 4) and transcription factor TGF-β inhibitors induce the formation of the skin;The spherical cell cluster begins to produce hair follicles after more than 70 days of cultivation and eventually grows hair. Most hairs are dyed by melanin cells, which are also developed by nerve cells in the brain. Subsequently, sebum glands, nerves and their subjects, fat and other hair follicle-related tissues also gradually developed. In addition to immune cells, near-complete skin has formed in petri dishes.To gain insight into the cell linees in skin organs, the researchers sequenced them with single-celled RNA and found that the genes expressed by skin organs had chin, cheek and ear skin characteristics. This shows that by changing the culture conditions of cell growth, skin with different body parts can be produced.The researchers then tested the therapeutic potential of organoids in the body in mouse experiments. After 140 days of culture, the researchers implanted skin organs into the backs of hairless mice and found that 55 percent of all foreign grafts had 2-5 mm of hair and were distributed on the surface of the graft.Benjamin Woodruff, of Oregon Health and Science University, said: "This shows that in the future we can produce scientific hair without acquiring human hair, and we can produce hair follicles in unlimited quantities." In, the study showed that near-complete skins can be self-assembled in vitro and can be reconstructed in the body. However, the hairs produced in this study were very short and further optimization of the culture conditions was needed to form larger hairs and long-term observations were made to determine the growth of heterogeneic transplant hair follicles. (Biological exploration)