"Scientists say they have moved a step closer to banishing bald spots," BBC News reveals. While the research only involved mice, it did provide "proof of concept" that it is possible to reprogramme human cells to grow hair.
The pioneering technique showed it was possible to take human papillae (cells present at the root of human hair) and grow them in a 3D spheroid in the lab. A 3D spheroid is a method of developing more complex types of cell cultures (where cells are grown under laboratory conditions) compared to conventional 2D techniques – such as growing cells in a Petri dish.
The cells were then injected into bald human skin grafted to the back of a mouse. This resulted in the formation of new hair follicles – the structures below the skin that produce hair.
The new technique shows it is possible to form completely new hair follicles where there weren’t any before, which is a significant step forward.
It appears the technique does have the potential to offer a new treatment if it can be developed to work in humans on a feasible scale and produce cosmetically pleasing results. However, the study authors themselves acknowledge that the technique needs a lot more development and refinement and that a baldness treatment may be a long way off.
Consequently, reports that a cure for baldness is a “hair’s breadth away” may reflect an interest in writing puns over the facts, whereas headlines reporting a “breakthrough” do appear to be justified.
The study was carried out by researchers from US and UK universities. The study had numerous funding sources, including a Science of Human Appearance Career Development Award from the Dermatology Foundation, the Biotechnology and Biological Sciences Research Council follow-on fund, a Medical Research Council Grant and New York State Foundation for Science Technology and Innovation and New York State Stem Cell Science grants.
The study was published in the peer-reviewed science journal Proceedings of the National Academy of Sciences (PNAS).
The media generally reported the science accurately, however many reports appeared to overemphasise the speed at which this new technique might develop into a treatment for baldness. The researchers themselves cautioned that it was early days, and it was not easy to estimate how long this would take. Headlines reporting that a new baldness treatment was a "hair’s breadth" away appeared more interested in puns than facts.
This was a laboratory study attempting to take material from the root of a human hair and use it to grow lots of new dermal papillae in the laboratory, which could later be transplanted back onto bald skin to produce new hair.
There are some structures of the hair that reside below the skin. Collectively these are known as hair follicles, which is where the hair is fastened and grows. The hair above the skin is known as the hair shaft, and is what most people are describing when they use the term hair.
The dermal papilla is a group of cells at the root of the hair shaft, below the skin, within the hair follicle.
Interestingly, in rodents it has long been possible to take the dermal papillae, grow them into many more cells in the lab and successfully transplant them back into bald skin where they can induce the formation of new hair-producing hair follicles.
So, the papillae’s potential to form new hair follicles and new hair has been the focus of a lot of regenerative hair research.
Unfortunately, scientists soon discovered this doesn’t work the same way in humans so have been working to better understand why the same changes don’t occur. The goal being to induce dermal papillae to develop into hair-producing follicles in the laboratory to mimic the hair regeneration possible in rodents.
The researchers took human papillae cells from seven human donors and attempted to grow more of them in the laboratory. After a number of failed attempts they succeeded in growing a group of papillae cells.
Once they had grown a group of papillae cells for a few days they transplanted them into human skin grafted onto the backs of mice to see if they were capable of inducing a hair follicle or hair shaft growth in the bald skin.
The genetic analysis showed that when the papilla cells were in a 2D environment they underwent many biological changes that may have been the cause of the failed development. They also noted that in successful rodent hair growth experiments the papilla cells clumped together in a ball, which did not occur in the attempts to culture the human cells. Putting these bits of information together they found that the 3D shape and interaction of the hair forming cells was of key importance in growing papilla cells and maintaining their ability to develop into a hair follicle.
They then grew papilla in a 3D spheroid structure and found this made the genetics of the cells more similar to normal hair cells.
After a few days the papilla spheroids were transplanted into bald human skin grafted onto the backs of mice and in five out of seven tests led to new hair growth that lasted at least six weeks. This mimicked the hair-inducing property found in mice many decades previously, but this time using human papilla cells and human skin.
The researchers concluded that creating the right environment for the papilla cells to clump together in a 3D spheroid was essential as it led to the development of cell structures similar to those seen in the natural development of hair. This also partially restored the cell’s hair-inducing properties.
Surgical implantation of the skin spheroids into a human skin sample (on the back of a mouse) induced human hair follicle formation which showed a proof of concept. They concluded that “these observations represent a significant advance in using cell-based therapy for hair-follicle neogenesis, bringing it closer to becoming a therapeutic reality”.
The study authors were also quoted in Sci-News.com as saying: “This approach has the potential to transform the medical treatment of hair loss. Current hair-loss medications tend to slow the loss of hair follicles or potentially stimulate the growth of existing hairs, but they do not create new hair follicles. Neither do conventional hair transplants, which relocate a set number of hairs from the back of the scalp to the front.” Furthermore, “our method, in contrast, has the potential to actually grow new follicles using a patient’s own cells. This could greatly expand the utility of hair-restoration surgery to women and to younger patients – now it is largely restricted to the treatment of male-pattern baldness in patients with stable disease”.
This laboratory research provides proof of concept for a new way of growing human hair. The technique showed it was possible to take human papilla cells, grow them in a 3D spheroid in the lab and then inject them into bald human skin. This resulted in new hair follicle formation and hair growth in five out of seven transplants.
While promising, the authors themselves acknowledge the technique needs a lot more development and refinement, and that a baldness treatment may be a long way off. For instance, there might be challenges ensuring the new hair would be the same colour, texture and grow to a desired length. Given this is such early research, these and other potential challenges will need to be overcome before any prospect of a usable treatment could come to market.
Nonetheless, the technique appears promising. Existing treatments for hair growth either stimulate hair growth in existing hair follicles, or simply surgically move hair from one place to another to improve the cosmetic look. The new technique shows it is possible to form completely new hair follicles where there weren’t any before, which is a step forward.
Due to the commercial potential of a "baldness cure" it is highly likely that further research, based on the techniques described in the study, will follow.