Mature hair follicles have been grown in a laboratory for the first time, in a move that could one day treat hair loss.
Artificially producing hair follicles has historically been very difficult, says Kairbaan Hodivala-Dilke at Queen Mary University of London, who wasn’t involved in the study. “Different types of cells need different sorts of nutrients and when they’re outside the body, they need different sorts of requirements compared to when they’re in the body.”
Among mammals, hair follicles are typically produced in embryos as a result of interactions between skin cells and connective tissue.
To better understand these interactions, Junji Fukuda at Yokohama National University in Japan and his colleagues studied hair follicle organoids – tiny, simple versions of an organ.
By controlling the organoids’ structure, the team was able to enhance hair follicle growth.
“We examined various conditions, including growth factors, activators and inhibitors of signalling pathways and essential culture medium components,” says Fukuda.
The team’s main breakthrough was culturing mice embryonic skin cells in a special type of gel, which allowed the cells to be reprogrammed into hair follicles.
“If you think of a hair follicle, it’s got the hair down the middle of it and then it’s got layers of epithelial cells around the follicle and other specialised cells,” says Hodivala-Dilke. The gel allows these cells to grow in a laboratory in a way that means they can climb over and around each other [like they do in the body], she says.
The hair follicles grew for up to one month, reaching up to 3 millimetres long. “This is probably related to the fact that the hair cycle of mice is about one month,” says Fukuda.
The team is now working to recreate the experiment using human cells.
According to Hodivala-Dilke, laboratory-grown human hair follicles could one day treat hair loss. “You might be able to take hair from someone whose hair is really lush and make it grow in the lab and then use those follicles to do a transplant,” she says. Existing hair transplants involve moving hair from one part of the body to an area that is thinning or bald, which can cause scarring.
A hair loss treatment breakthrough
The new research was published in the journal Science Advances, with a team of researchers from Yokohama National University generating hair follicles in cultures.
In a press release, the research team explain that this work centered on the practice of performing “organoid” — small “simple versions of an organ” — cultures that have increasingly received a spotlight in research performed to better understand organ and tissue development.
The researchers explain that when an embryo forms, something akin to a series of messages shoots back and forth between the epidermal layer of the skin and the mesenchyme, or the skin’s connective tissue.
These signals spur the creation of hair follicles, a process known as morphogenesis, where an organism’s cells come together to form the body’s organs and tissues. They note how difficult it has been in the past for researchers to completely understand what goes on behind hair follicle development, and this morphogenesis process for hair follicles has not, until now, been reproduced in a culture dish.
For this study, the researchers used rodent embryonic cells — this is due to “their shorter period of hair generation, higher hair-inducing activity, and availability compared to cells of human origin,” according to the study.
“We were surprised that hair follicle tissues capable of producing hairs could be obtained by culture,” study author Junji Fukuda, PhD, professor with the faculty of engineering at Yokohama National University. “It was even more surprising that we were able to increase the probability of hair formation from less than 1% — one out of 300 cell aggregates — at the beginning of the research to almost 100% — or 300 out of 300 cell aggregates — in this study.”
They were able to create these tiny hair follicles by controlling the structure created by those back-and-forth communications between embryonic cells by way of a “low concentration of extracellular matrices,” which is the network in your body that offers structure for your tissue and cells. The team grew hair shafts and hair follicles “with almost 100% efficiency,” generating “fully mature hair follicles with long hair shafts,” according to the release.
The follicles that were created were fully mature, measuring about 3 mm in length, in 23 days of culture.
The researchers were able to then examine that morphogenesis process as well as hair pigmentation in vitro, getting a better comprehension of that signal-to-signal process that spurs this follicle growth.
“Our system provides a continuous in vitro observation of the process of new hair follicle formation. Thus, it can help us to better understand how hairs are formed and what happens when certain external stimuli are applied in the process,” Fukuda said. “We can also continuously observe how melanosomes [organelles that process and hold melanin pigments] are passed on to the hairs and pigmented, which can be used to understand the causes of gray hairs and to develop drugs to treat them.”
How hair loss treatments are determined
While this new research offers a tantalizing picture of what could be possible if you are experiencing hair loss right now, what avenues currently exist?
Dr. Peter Young is the medical director for Keeps, which specializes in treatment for men’s hair loss by way of FDA-approved, home-delivered treatments.
Young, who is unaffiliated with the new research out of Japan, said that it is all dependent on the type of hair loss you might be experiencing. You might be able to reverse this hair loss and grow new hairs, or just slow down the process at the least. To figure out what is the right method, Young said you have to figure out the cause of a specific individual’s hair loss.
“In order to determine the cause and best treatment for your hair loss, your provider will take a thorough history. focusing on the various medical conditions that can cause hair loss, including thyroid disease, anemia, and autoimmune conditions such as lupus,” Young explained. “The provider will also inquire about physical or emotional stressors that may have led to your hair loss and request a list of your current medications.”
Next, your provider will visually examine your scalp. This is due to the fact that different kinds of hair loss appear in different ways to the naked eye. If the underlying cause is still unclear after this kind of examination, your provider might then recommend blood work and even take a biopsy of your scalp and look at that sample under a microscope, he added.
“If your hair loss is caused by an underlying disease, such as thyroid disease or anemia, then treatment for that disease will be necessary to reverse the hair loss. There are various medications that can lead to hair loss, for example, certain blood pressure medications. If you’re on one of these medications and experiencing hair loss, then your doctor may switch you to a different medication,” Young said.
Beyond this, a condition like alopecia areata, which is marked by a patchy form of “hair loss of uncertain cause,” the hair might “spontaneously regrow without treatment” over a period of months or even a year.
Hair loss treatments currently available
Accepted treatments that exist include medications, laser, and hair restoration surgery, Young added. The most common treatments for male pattern baldness include medications like minoxidil — commonly known by the brand name Rogaine — and finasteride, which goes by the brand name Propecia.
He added that minoxidil is an over-the-counter medication that will come in liquid or foam form and is available at two strength levels.
“It takes at least three to four months to start seeing results from topical minoxidil and one to two years to see optimal results. You need to continue using the medicine indefinitely to maintain the benefits. The most common side effect of topical minoxidil includes scalp irritation, itching, or redness,” he added. “This is less common with the foam formulation than with the solution. Some patients may develop unwanted facial hair growth.”
Outside of minoxidil, finasteride is a prescription pill for men with male pattern baldness. Many who take this medication will see new hair growth or the slowing of their existing hair loss. This might also take a few-to-several months for you and your provider to figure out whether it’s working for you. You might need to keep taking it to sustain the benefits.
“Rare side effects of finasteride include erectile dysfunction and decreased sex drive. It’s important for women who are or may be pregnant to avoid touching crushed or broken tablets since it can cause birth defects,” he added.
When it comes to hair restoration or hair transplant surgery, Young said a dermatologist or cosmetic surgeon will move existing hair from a part of the scalp that has hair and will transplant it to a part of the scalp that is thinning. This is often the crown of the head. He added that usually more than one surgery session might be needed “to get the desired level of improvement, and the procedure can be very costly.”
“Low-level laser therapy was approved by the FDA several years ago and may be helpful in treating hereditary hair loss in both men and women,” Young added.
The implications for hair growth and beyond
This new research has wide-ranging implications for contributing to our continued understanding of the processes behind hair generation.
Young told Healthline that this study was important in contributing to “our current understanding of hair follicle development” and that it “may have useful applications for the future in treating hair loss.”
When asked what his research signifies down the line, Fukuda said that, due to the fact the system they developed “can screen drug candidates based on the status of hair growth,” it should ultimately “give more accurate results than the conventional approach using cells on a culture dish.”
“For hair regenerative medicine application, our method prepares hair follicles with hair shafts before transplantation, which may greatly improve the efficiency of hair regeneration compared to the method that produce hair follicles after cells or cell aggregates are transplanted into the skin. Our approach is similar to current hair transplantation,” he added.
This research has implications in other areas of regenerative medicine beyond hair growth.
Given that the hair follicle is a mini organ regenerated in vitro, Fukuda said the results of his team’s study offers “an important perspective” on regulation of “the initial arrangement of cells in an aggregate” in harnessing their regenerative potential in those early stages of embryonic development.