Sprouting Hair Follicles

For the first time ever, scientists have successfully grown hair follicles from cultures of stem cells. Researchers at the Indiana University School of Medicine developed the new method for making hairy lab-grown skin from mouse pluripotent stem cells.

While it might seem like hair transplant mad science gone wrong at first, this method could be used to model diseases, develop therapies, or even treat skin disorders and cancers. Published online in the journal Cell Reports, this research builds on the team’s previous work developing a technique to grow inner ear cells from stem cells.

 Hair follicles (red) grow out of spherical skin organoids. Image Credit: Jiyoon Lee and Karl R. Koehler.
Hair follicles (red) grow out of spherical skin organoids. Image Credit: Jiyoon Lee and Karl R. Koehler.

The recent study was led by Karl Koehler, an assistant professor at IU School of Medicine. In an IU press release, Koehler said, “The skin is a complex organ that has been difficult to fully recreate and maintain in culture for research purposes. Our study shows how to encourage hair development from lab-grown mouse skin, which has been particularly troublesome for researchers to recreate in culture.”

This study identified stem-cell-culture conditions that allowed epidermis and dermis mouse cells to form a sphere-like cluster of cells called a skin “organoid.” Under these conditions, the organoids developed like skin in an embryo. Koehler elaborated in the press release, “After about 20 days, we were amazed to see that skin organoids sprouted hair follicles. The roots of the follicles protrude from the skin organoids in all directions.”

Lab-Grown Skin

After validating their findings, the researchers have begun to explore the theoretical applications of this work. Jiyoon Lee, a postdoctoral fellow in Koehler’s lab and first author on the study, thinks this research could one day allow scientists to create an entire skin organ from “scratch.”

“My hope is that by improving skin-in-a-dish models we can greatly diminish the sacrifice of experimental animals and ultimately help patients with skin-related issues live a better life,” Lee said in the press release.

An Exponential Timeline of Organ Transplants
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However, Koehler cautioned that there are still technological hurdles the team must overcome before this type of lab-grown skin can be applied in the ways that they intend. First, this experiment has not been performed with human stem cells yet. Additionally, the skin organoids are missing immune cells, blood vessels, and nerve endings that are found in skin that grows over bodies.

“The shape of skin organoids is another problem that needs to be addressed in the future,” Koehler elaborated in the press release. “Because the organoids are inside-out compared to normal skin, the layers of dead cells and hairs cannot be shed as they are normally, so we need to find a way to flip the structure of skin organoids.”

If and when these challenges are overcome, this technique could revolutionize research by providing a skin model that could be more effective and preferable to animal testing. Not only could these skin organoids push forward research into skin diseases and cancers, they could one day even provide suitable alternatives to traditional skin grafts.