The Future

Cloning Hair

The thought of being able to culture hair follicles and have an unlimited donor supply has been a long-time dream of patients with hair loss and hair restoration surgeons alike. The obstacles, however, have seemed enormous since the hair follicle is a very complex structure of skin cells, blood vessels, nerves, muscles, and glands. (As an analogy, culturing a hair follicle would be more like culturing an entire eyeball rather than just the cells of the cornea.) Now there is hope that not only is cloning possible, but that this hair may not even need to be your own.

Dr. Colin Jahoda, a British scientist recently reported that he took dermal sheath cells (cells from the lowest part of the hair follicle) from his own scalp and transplanted them into his wife's forearm. These implanted cells then stimulated his wife's skin to grow new hair. The hair was analyzed by Dr. Angela Christiano at Columbia University in New York and was show to be composed of cells with Dr. Jahoda's XY chromosomes at the bottom and his wife's XX chromosomes at the top.

This clever experiment shows that the hair follicle's dermal sheaths cells are one of the bodies "immune privileged" organs, enabling them to be transplanted from one person to another without rejection. More importantly, this study suggests that all one might need to do is to transplant these "inducer" cells to stimulate new hair growth, rather than having to transplant the entire follicle itself. The great significance, for those that are balding, is that these cells may some day be cultured in the lab, to produce a potentially unlimited supply of hair.

At the 2003 meeting of the ISHRS, Dr. Jerry Cooley succinctly pointed out the problems that still confront us in cloning hair (or what he more accurately terms Follicle Cell Implantation). First, there is the need to determine the most appropriate follicular components to use (dermal sheath cells, the ones used in the Collin/Jahoda experiment, are hard to isolate and may not actually produce the best hair). Next, these extracted cells must be successfully cultured outside the body. Third, a cell matrix might be needed to keep them properly aligned while they are growing. Finally, the cells must be successfully injected into the recipient scalp in a way that they will consistently induce hair to grow.

Unlike, Follicular Unit Transplantation (FUT), in which an intact follicular units are planted into the scalp in the exact direction the surgeon wants the hair to grow, with cell implantation there is no guarantee that the induced hair will grow in the right direction or have the color, hair thickness or texture to look natural. To circumvent this problem, one might use the induced hair in the central part of the scalp for volume and then use traditional FUT for refinement and to create a natural appearance. However, it is not even certain that the induced follicles will actually grow long enough to produce cosmetically significant hair. And once that hair is shed in the normal hair cycle, there are no assurances that it will grow and cycle again. (Normal hair grows in cycles that last 2-6 years. The hair is then shed and the follicle lies dormant for about three months before it produces a new hair and starts the cycle over again.)

A major technical problem to cloning hair is that cells in culture begin to de-differentiate as they multiply and revert to acting like fibroblasts again, rather than hair. Finding the proper environment in which the cells can grow, so that they will be maintained in a differentiated (hair-like) state, is a major challenge to the researchers and appears to be the single greatest obstacle to this form of therapy coming to fruition. This is not unlike the problems in cloning entire organisms where the environment that the embryonic cells grow in is the key to their proper differentiation and survival.

Finally, although remote, there may be safety concerns that cells that induce hair may also induce tumors, or exhibit malignant growth themselves. Once these obstacles have been overcome, there are still the requirements of FDA approval which further guarantees safety as well as effectiveness. This is a process that involves three, very formalized stages of clinical testing and generally takes years.

On the status of cloning - it is still a work in progress. Although there has been much recent success, and we finally have a working model for how cloning hair might eventually be accomplished, much work still needs to be done.