Dr. Xiaowei "George" Xu, associate professor of pathology and laboratory medicine and dermatology at the Perelman School of Medicine at University of Pennsylvania, and colleagues at the New Jersey Institute of Technology, said they started with human skin cells called dermal fibroblasts.
By adding three genes, they converted those cells into induced pluripotent stem cells, which have the capability to differentiate into any cell types in the body. They then converted the induced pluripotent stem cells into epithelial stem cells, normally found at the bulge of hair follicles.
Starting with procedures other research teams had previously worked out to convert induced pluripotent stem cells into keratinocytes, Xu's team demonstrated that by carefully controlling the timing of the growth factors the cells received, they could force the induced pluripotent stem cells to generate large numbers of epithelial stem cells.
The team succeeded in turning more than 25 percent of the induced pluripotent stem cells into epithelial stem cells in 18 days.
Those cells were then purified using the proteins they expressed on their surfaces.
"This is the first time anyone has made scalable amounts of epithelial stem cells that are capable of generating the epithelial component of hair follicles," Xu said in a statement. "And those cells have many potential applications including wound healing, cosmetics and hair regeneration."
The findings were published in Nature Communications.