iPSCs — The Final Cure for Baldness?

iPSCs — induced Pluripotent Stem Cells — are stem cells that have been produced from adult cells using a variety of retroviruses. First developed in 2006 by Shinya Yamanaka, these cells in theory hold all of the advantages of embryonic stem cells without any of the ethical dilemmas posed by their use.

iPSCs can have many uses, and iPSC data banks have literally been popping up all over the US in order to allow scientists to purchase iPSCs for experiments. One of the more important breakthroughs however happened in January 2015. Scientists at the Sanford Burnham Medical Research Institute successfully grew new human hair follicles on mice using iPSCs.

Understanding Hair Growth

In order to truly understand the magnitude of this discovery, one need first understand how human hair grows.

Hair is produced by hair follicles under the scalp. Interestingly enough, humans are born with all of the hair follicles they will ever have. We do not have the ability to generate new hair follicles, which is why burn victims never grow their hair back, and why baldness seems so irreversible despite so many marketing claims.

Our hair follicles, however, do not continuously produce hair. Rather, they each go through a cycle. First comes the anagen phase, where the hair follicle produces hair, followed by the catagen phase, where production stops, the telogen phase, where the follicle rests, and finally, again, the anagen phase where hair production starts anew. At any given time, as much as 20% of our hair follicles can be in the telogen phase.

However, when baldness (partial or total) sets in, hair follicles are stuck in the telogen phase and do not restart the cycle, sometimes simply regressing and disappearing, creating a permanent problem.

Current Solutions to Hair Loss are Inadequate

There currently exist three main types of treatment for hair-loss: Minoxidil, Finasteride, and Hair Transplants.

Minoxidil works along a simple concept: it increases blood flow (and therefore nutrition) to the hair follicles, hence stimulating growth. However, it faces three major flaws: it needs daily application, which can become quite a burden, it loses its effectiveness over time, and most importantly, it does not create new hair follicles.

Finasteride, on the other hand, is a DHT inhibitor, and claims to restore normal function to dormant follicles (those in the telogen phase). However, it faces the very same issues as Minoxidil: needs daily application, loses effectiveness over time, and does not produce new hair follicles.

Hair Transplants are a completely different procedure. Hair follicles from other parts of the body are first extracted, and then surgically installed into balding areas. These follicles then pick up their classic cycle, but in another location. In contrast to the first two options, hair transplants do not require daily application, nor do they lose their effectiveness over time (so long as the implanted hair follicles do not become permanently dormant). However, hair transplants are a very expensive procedure (which can clock in at over $10,000 per procedure), severely limiting its growth. Most importantly, it does not prevent further hair loss, and therefore acts as somewhat of a stop-gap measure.

iPSCs Can Solve This Problem

iPSCs have the potential to solve this problem completely because of one simple reason: it is the only solution which actually produces new, functional hair follicles.

Using a patient’s own skin cells, scientists use a variety of retroviruses to transform them into induced Pluripotent Stem Cells — these can be grown in “unlimited quantities”. The iPSCs are then converted first into neural crest cells, and from there into DP cells (dermal papillae cells), a cell closely linked to the development of hair follicles. Finally, the cells are then implanted into the epidermis, and generate new hair follicles.

Who Is Working on This?

So far, two main scientific teams seem to be focused on the use of iPSCs for hair-loss treatments. A team from the Perelman School of Medecine in Pennsylvania, led by Xiaowei (George) Xu created epithelial cells from iPSCs which sparked an incomplete creation of hair follicles, due to the lack of DP cells. Meanwhile, the team from the Sanford Burnham Medical Research Institute in San Diego led by Alexey Terskikh used iPSCs to create DP cells, implanted them on mice, and obtained the formation of human hair follicles. Their next stated goal is, quite obviously, human trials.

Hair-Loss Treatments is a Huge Opportunity

Hair-loss is an important issue due to the psychological burden it can create. In the US alone, 40% of men experience visible hair-loss by age 35, and 65% by age 60. This is not a male-only problem however: 40% of total hair-loss sufferers are estimated to be women.

Meanwhile, the worldwide market for surgical hair restoration alone (not including creams or similar products), was worth a whopping $2.5 billion in 2014, and has grown close to 13%/year over the last two years.

Although the price of using iPSCs as a hair-loss treatment method is yet to be determined, it is safe to assume it will be closer to hair transplants than to Minoxidil or Finasteride, as it also requires surgical procedures. However, even at that price point, the market in the US alone accounted for $1 billion in 2014.

Furthermore, the industry itself seems quite recession-resistant. Despite the global crisis in 2008–2010, hair restoration procedures grew 3%/year in Europe and the US (and 17% in Asia!)

Still A Long Way Off…

There remain however, two key areas that need to be explored by researchers before iPSCs become the next big thing in hair restoration.

First of all, hair normally grows out at characteristic angles to the skin, which is what hair stylists use to create hairstyles. However, transplanted DP cells resulted in hair growing out at a variety of angles. It remains to be seen if the final effect is still suited to consumer expectations (is messy hair better than no hair?) or if hair directionality can be improved during the transplantation process.

More worryingly, iPSCs are fairly recent, and rely on retroviruses. As in any procedure using retroviruses, more research needs to be done to ascertain that the retroviruses used in the generation of iPSCs do not trigger cancer-causing genes.

iPSCs Could Become a Revolutionary Solution — But We Are Still Years Away

The logic and scientific backing behind iPSCs is not only sound — it has created what is by far the best option on the market for hair restoration: a solution capable of creating new hair follicles. Although a significant amount of research is still required, and FDA approval for the procedure guarantees that the process will take many, many years, there is no doubt in my mind that this solution will prove to be a game-changer in the hair-loss space. Watch it closely.