In a first, scientists grow fully mature hair follicles in cultures

Researchers from Japan generated hair follicles in cultures while working on the processes of hair follicle growth and hair pigmentation, according to a press release delivered today (Oct .21). This achievement could contribute to the development of different applications such as hair loss treatment, animal testing and drug screenings.

Hair follicles develop through a process called morphogenesis when the outer layer of skin and the connective tissue interacts while the embryo develops.

Scientists have been trying to understand the essential mechanisms of hair follicle development through animal models, however; hair follicle morphogenesis wasn’t something that could be reproduced in a culture dish as they haven’t figured out how these mechanisms worked until now.

Tapping into the power of organoids for understanding hair follicle mechanisms

“Organoids were a promising tool to elucidate the mechanisms in hair follicle morphogenesis in vitro” said Tatsuto Kageyama, an assistant professor with the faculty of engineering at Yokohama National University.

Researchers built hair follicle organoids by controlling the structure generated from the two types of embryonic cells tapping into a low concentration of extracellular matrices.

The extracellular matrix is a network that supplies structure for cells and tissue in the body. These matrices changed the spacing between the two types of embryonic cells from a dumbbell-shape to core-shell configuration. Then, hair follicles that have been formed with typical features occurred in core-shell-shape groups.

These groups expanded the contact area between two cell regions to enhance the mechanisms that contribute to hair follicle growth.

The organoid cultures generated hair follicles and hair shafts almost at a 100 percent efficiency level. Fully mature hair follicles with approximately 3 millimetre (mm)-long hair shafts were produced by the hair follicle organoids on the 23rd day of being cultured.

This way, researchers have been able to better observe the hair follicle morphogenesis and hair pigmentation in vitro and comprehend the signaling pathways incorporated in the processes.

Next: Regenerative medicine

Researchers included a melanocyte-stimulating drug that helps produce hair color pigmentation in the culture medium. Thanks to the drug, hair pigmentation of the hair-like fibers improved notably. Also, they achieved efficient hair follicle regeneration with repeating hair cycles after adding the hair follicle organoids.

The findings could help understand how physiological and pathological processes develop in relation to other organ systems as well. “Our next step is to use cells from human origin, and apply for drug development and regenerative medicine,” said Junji Fukuda, a professor with the faculty of engineering at Yokohama National University.

The findings have been published in the journal Science Advances.