Bioengineered hair

At the RIKEN Biosystem Dynamics Research Center in Japan, a group led by Takashi Tsuji is working on ways to restore lost hair from stem cells. In the new study, they took hair follicles of wool and whiskers from mice and cultured them in the laboratory with other biological ingredients. The researchers used 220 combinations of ingredients and found that the combination of one type of collagen with five factors (Noggin protein, fibroblast growth factors FGF-7 and FGF-10, Sonic hedgehog gene agonist and epidermal growth factor EGF – medium NFFSE) led to the highest rate of stem cell amplification in the shortest period of time.

Mammalian hair growth is a continuous cyclical process in which hair grows, falls out and grows back. Growth occurs in the anagen phase, and hair falls out in the telogen phase. Thus, a successful hair regeneration procedure should lead to cyclic hair regeneration. To test whether hair is cyclically produced from stem cells, the researchers placed bioengineered hair follicle stem cells in an NFFSE medium and in an environment without one of the ingredients and observed hair regeneration for several weeks. They found that 81% of the hair follicles cultured in the NFFSE medium underwent at least three cycles and produced normal hair growth, while 79% of the follicles grown in another medium produced only one hair growth cycle.

Top row: hair regeneration in the NFFSE environment; the cycle repeats 4 times (growth, loss, new growth, etc.). Bottom row: hair regeneration in an environment devoid of one of the important components; the cycle repeats only once.

Knowing that the renewal of stem cells may depend on their microenvironment, the researchers looked for markers on the surface of cells cultured in the NFFSE medium. In addition to the expected CD34 and CD49f markers, they found that the best growth cycle in many characteristics was associated with the addition of integrin β5 (Itgß5).

Diagram of the mouse hair follicle. In the presence of Itg-beta5 on the upper part of the hair follicles, the hair growth cycle was repeated at least three times.

Almost 80% of the follicles achieved three cycles of hair growth when Itgß5 was bioengineered into the hair follicle embryo, and only 13% achieved three cycles when Itgß5 was not. The analysis showed that these important cells are naturally located in the upper part of the hair follicle.

Thus, the new cultivation system creates conditions for optimal cyclic regeneration of hair follicles from stem cells. Since preclinical safety trials in animals using these cultured cells were completed in 2019, clinical trials will be the next step in this process.

Article M.Takeo et al. Expansion and characterization of epithelial stem cells with potential for cyclic hair regeneration is published in the journal Scientific Reports.

Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of RIKEN: A recipe for regenerating bioengineered hair.