Japanese Researchers Grow Functional Hair Follicles in the Lab, Offering Hope for Hair Loss Treatment

For approximately 25% of the world’s population, hair loss – whether due to aging or conditions like alopecia – is a common concern.¹ Current treatments like minoxidil and finasteride can only unhurried down hair loss, but a recent breakthrough by Japanese researchers may offer a path towards restoring lost hair.

A team led by researchers Koh-ei Toyoshima and Takashi Tsuji has successfully grown functional hair follicles in a laboratory setting, mimicking the natural cycle of growth, shedding, and regrowth. The findings were published in Biochemical and Biophysical Research Communications.

The Missing Piece: Mesenchymal Companion Cells

Previous attempts to recreate hair follicles in the lab relied on two known cell types: stem cells from the hair root and cells from the dermal papilla, a control center at the base of the follicle. While these cells formed a basic hair bulb, they failed to grow downwards into the skin, a crucial step for forming a complete, functional follicle.²

The Japanese team discovered that the key to successful follicle growth lies in a third cell type: mesenchymal companion cells. These cells reside in the connective tissue surrounding existing hair roots and act as a scaffolding, guiding the growing follicle deeper into the skin.² Only when all three cell types were combined did complete follicles develop, forming a visible hair shaft.

How the Three Cell Types Work Together

The researchers utilized an organ germ method, refined over decades, to create a tiny biological germ from the three cell types. The mesenchymal cells performed a dual role: transforming into dermal sheath cells, which form a protective shell around the growing follicle, and providing mechanical support for the hair’s downward growth.²

In a three-dimensional skin model, these lab-grown follicles exhibited a natural hair cycle – forming hair shafts, growing, shedding, and then regrowing. This cycle is a hallmark of healthy hair.

Successful Transplantation into Mice

The follicles also demonstrated functionality in vivo. When transplanted into mice, they integrated into the surrounding tissue, connecting with nerves and the hair follicle muscle responsible for causing goosebumps.² Over 68 days, the transplanted hair cycled through its natural growth phases.

“This work defines a fundamental cellular configuration for functional hair follicle regeneration,” said Yoshio Shimo, head of OrganTech, a company that co-financed the study.

Future Outlook and Challenges

While these results are promising, significant hurdles remain before this technology can benefit humans. All tests have been conducted on mice, and replicating the process with human tissue presents additional complexities, particularly in isolating the necessary cells. Currently, there is no established timeline for clinical studies.