Skin tissue with hair grown successfully from mice cells

In a first, scientists have successfully grown skin tissues complete with hair follicles using stem cells of mice, that can be used for drug testing and understanding hair growth.
The skin model more closely resembles natural hair than existing models and may prove useful for reducing the practice of animal testing.
Karl Koehler, assistant professor at the Indiana University in the US, originally began using pluripotent stem cells from mice, which can develop into any type of cells in the body, to create organoids - miniature organs in vitro - that model the inner ear.
However, researchers discovered that they were generating skin cells in addition to inner ear tissue, and their research shifted towards coaxing cells into sprouting hair follicles.

The research demonstrates that a single skin organoid unit developed in culture can give rise to both the upper and lower layers of skin, which grow together in a process that allows hair follicles to form the same way as they would in a mouse's body.
While the researchers were unable to identify exactly which types of hairs developed on the surface of the organoid, they believe the skin grew a variety of hair follicle types similar to those present naturally on the coat of a mouse.

The skin organoid itself consisted of three or four different types of dermal cells and four types of epidermal cells - a diverse combination that more closely mimics mouse skin than previously developed skin tissues.

By observing the development of this more lifelike skin organoid, the researchers learned that the two layers of skin cells must grow together in a specific way in order for hair follicles to develop.
As the epidermis grew in the culture medium, it began to take the rounded shape of a cyst. The dermal cells then wrapped themselves around these cysts. When this process was disrupted, hair follicles never appeared.
Koehler thinks the mouse skin organoid technique could be used as a blueprint to generate human skin organoids.
"It could be potentially a superior model for testing drugs, or looking at things like the development of skin cancers, within an environment that's more representative of the in vivo microenvironment," said Koehler.

"And it would allow us to limit the number of animals we use for research," he said.