It's been theorised for years, but now human stem cells have resulted in hair growth for the very first time.
"We have developed a method using human pluripotent stem cells to create new cells capable of initiating human hair growth. The method is a marked improvement over current methods that rely on transplanting existing hair follicles from one part of the head to another," said Alexey Terskikh, Ph.D., associate professor in the Development, Aging and Regeneration Program at Sanford-Burnham.
"Our stem cell method provides an unlimited source of cells from the patient for transplantation and isn't limited by the availability of existing hair follicles."
The process started with human pluripotent embryonic stem cells -- that is, stem cells that are capable of developing into any other cell -- which were then developed into neural crest cells. These are cells that can develop into a variety of cells on the head, including brain cells, cartilage, bone and muscle cells.
From the neural crest cell point, the team coaxed the cells to grow into dermal papillae cells, the cells that nourish the skin and regulate follicle growth and formation. When transplanted -- in the case of this study, into hairless mice -- these cells flourish.
Another part of the study examined whether the same result could be achieved using dermal papillae cells taken from the scalps of adult humans. Outside the body, living in culture, these cells are not suitable for hair transplants, since they lost their ability to induce follicle formation. The number of hairs their produced was insignificant.
"In adults, dermal papilla cells cannot be readily amplified outside of the body and they quickly lose their hair-inducing properties," said Terskikh. "We developed a protocol to drive human pluripotent stem cells to differentiate into dermal papilla cells and confirmed their ability to induce hair growth when transplanted into mice."
The researchers say that their research represents the first step towards a cell-based treatment for hair loss, which affects 40 million men and 21 million women in the United States.
"Our next step is to transplant human dermal papilla cells derived from human pluripotent stem cells back into human subjects," said Terskikh. "We are currently seeking partnerships to implement this final step."
You can read the full study, "Derivation of Hair-Inducing Cell from Human Pluripotent Stem Cells", online in the journal PLOS One.