Stem cells have been used to induce human hair growth in mice in a US study. The researchers say their work could represent the first step in creating a cell-based treatment for male pattern baldness, or androgenetic alopecia, which affects almost half of all men by the age of 50.
'We have developed a method using human pluripotent stem cells to create new cells capable of initiating human hair growth,' said Dr Alexey Terskikh from the Sanford-Burnham Medical Research Institute in California, who led the study.
In fact, the method developed relies on human embryonic stem cells, a fact which may limit its clinical utility.
Current methods for treating baldness involve transplanting existing hairs from one area of the head, or body, to the balding part. They are therefore limited by the availability of the patient's existing hair follicles. But, Dr Tersikh points out, the new method could 'provide an unlimited source of cells from the patient for transplantation'.
Using human embryonic stem cells, which can differentiate to form any cell in the body, the researchers first generated dermal papilla cells. These specialised cells are crucial in regulating hair follicle growth and development.
The team injected the lab-grown cells under the skin of hairless mice. When injected, the dermal papillae activated the existing hair follicles in the mice and induced 'robust' hair growth.
In the past, scientists attempted to culture dermal papilla cells but the cells ability to induce follicle growth was weakened by amplification. By using stem cells to create new dermal papilla cells, this problem was bypassed.
Dr Terskikh said that the next step for the research would be 'to transplant human dermal papilla cells derived from human pluripotent stem cells back into human subjects'.
The research was published in the journal PLOS ONE.