Scientists 3D-print hair follicles in lab-grown skin

This work, published in Science Advances, marks the first instance of using 3D-printing technology to generate hair follicles, a critical component in skin healing and function.

While the prospect of engineering skin grafts that can grow hair is still a few years away, this discovery holds significant potential for regenerative medicine and drug testing. Pankaj Karande, Ph.D., who led the study, underscores the importance of this advancement: “Our work is a proof-of-concept that hair follicle structures can be created in a highly precise, reproducible way using 3D-bioprinting. This kind of automated process is needed to make future biomanufacturing of skin possible.”

Karande also highlights the historical challenges in reconstructing hair follicles using human cells. He explains: “Some studies have shown that if these cells are cultured in a three-dimensional environment, they can potentially originate new hair follicles or hair shafts, and our study builds on this work.”

Hair follicles are more than mere aesthetic features; they play a vital role in skin physiology. They produce sweat, aiding in body temperature regulation, and contain stem cells crucial for skin healing. Hair follicles also serve as entry points for topical drugs and cosmetics, making them vital for dermatological testing. Carolina Catarino, Ph.D., first author of the study, notes: “Increasing [skin models'] complexity by adding hair follicles would give us even more information about how skin interacts with topical products.”

Deepak Vashishth, Ph.D., Director of the Shirley Ann Jackson, Ph.D. Centre for Biotechnology and Interdisciplinary Studies, lauds Dr. Karande’s lab for its work in skin tissue engineering. The team has previously printed skin with functional blood vessels, and this latest research is a significant step forward.

Shekhar Garde, Ph.D., dean of Rensselaer’s School of Engineering, also commends the work: “Bringing multichannel 3D printing to the biological realm is opening exciting opportunities that would have been hard to imagine in the past.”

The researchers created follicle-bearing skin using adapted 3D-printing techniques suitable for cellular-level printing. The process begins with multiplying skin and follicle cells in the lab, followed by mixing them with proteins to form a ‘bio-ink’. This bio-ink is then meticulously deposited layer by layer by the printer, creating channels for the hair cells around which the skin cells migrate, forming follicle structures.

Currently, these tissues last two to three weeks, insufficient for hair shaft development. The research team aims to extend this lifespan, allowing the follicles to mature further. This advancement could pave the way for their use in drug testing and skin grafts, heralding a new era in skin tissue engineering and regenerative medicine.