Cloning: The Future's Answer to Hair Loss
By: Angela Christiano, PhD
By: Animesh A. Sinha, MD, PhD

Q: What is the current state of the art in hair transplantation?
ANIMESH SINHA, MD, PhD: There have been tremendous advances in hair transplantation surgery over the last couple decades. You may remember the old-fashioned plugs that were the horror stories from two or three decades ago...well the science and the surgical techniques have evolved into single-graft transplants and micrografts that have allowed for much more natural redefinition of the hairline.

Q: Could you explain how cloning technology might work for hair?
ANGELA CHRISTIANO, PhD: The theory of hair follicle cloning involves taking a few hair follicle cells from your own scalp -- usually in the back -- or a donor area, and growing or cultivating large populations of your own cells in a laboratory, and then surgically reimplanting those cells into the scalp at the front of the head.

We're not talking about trying to recreate a whole person from a single hair follicle, so the challenge isn't nearly as great as it was to make an entire organism from one cell. What we want to be able to do is use your body's own cells to regenerate structures that have begun to atrophy or die. The technology is being widely applied in many areas of medicine, and involves trying to get your body to do what it knows how to do, but for some reason cannot anymore.

Q: Are you actually growing hair in the lab? Or just cells?
ANGELA CHRISTIANO, PhD: One of the great limitations of hair biology is that we don't yet know how to grow a hair in a dish, and if we did we'd be in a lot better shape. Right now we have no good way to do that, so what we're really just hoping to do is to culture the important cells-the germinative cells-and then reimplant those into the scalp, and then to let nature take its course, to basically allow those cells to induce a brand-new hair follicle.

Q: Has this been done?
ANGELA CHRISTIANO, PhD: In theory, it's already been done. Last year, a paper was published in Nature which showed that between a different donor and a different recipient, those particular cells could be implanted in the forearm of the recipient, and even in an area where no hair usually grows, those cells were powerful enough to induce a new hair follicle. No one has successfully done it on a large scale. If you use your own cells, of course the hair should be the same color, but there's the question of growth direction, and the most important question with the new hair is actually cycle-or whether or not it will have the ability to grow back once it's fallen out.

Q: How new is this technology?
ANGELA CHRISTIANO, PhD: The field of tissue engineering is just coming into its own, and the technology to grow cells and propagate them, to keep them alive in the lab, is relatively new. More important about these particular types of cells is keeping them in what we call a primitive state. We don't want them to differentiate or grow up into mature skin or hair cells. We want to keep them immature, because we think that in their immature state is when they have the instructions that dictate how to make a hair, so the laboratory techniques are just coming of age. In addition, the surgical techniques for learning how to reimplant cells in a given direction in a uniform way is something that will bring us back to the clinic. Eventually, it will be medical practitioners who probably implant these cells into recipient patients. With current technology, hair is simply taken from the back of your head and moved to the front of your head, so you're working with a finite number of hair follicles. The beauty of cloning is that you could actually increase the overall number of follicles, because you wouldn't need to harvest too many from the back, yet you could build more in the areas where you need hair.

Q: Is it necessary to use your own hair follicles, or could you use hair follicles from somebody else?
ANGELA CHRISTIANO, PhD: One of the nicest things about male pattern hair loss is that the area in the back of the head, the fringe, is preserved. In most cases, it's actually protected from male pattern baldness for reasons we don't understand. One of the most important lessons from hair transplantation has been the concept of donor dominance. That is, when you move good hairs from the back of the head to the front, they maintain the character from the back of the head and they don't usually fall out once you move them to the front. So I think the concept of using a different donor is probably not even necessary, although the experiment that was published last year was between a male and a female, very different donors and recipients.

Q: In that case, when the donor and recipients are different individuals, is there a risk or a problem with rejection?
ANGELA CHRISTIANO, PhD: In this particular case, the donor and recipient were not immunologically matched. They had been tested and they weren't compatible. In the first three hairs that were grown, there was no evidence for an overt immune response, so it didn't seem as though the body was rejecting the new hair.

ANIMESH SINHA, MD, PhD: That might open up a whole new source, a bigger source of potential donors, and you might even have designer choices of color and texture.

Q: Are there any obstacles that are in front of you as you go down this cloning road?
ANGELA CHRISTIANO, PhD: Sure. I think right now the biggest obstacle is learning how to keep the cells alive, and then once you put them back in, getting them to make new hair. So the technical aspects are still being worked out, but in theory I think it's certainly approachable. It's something we might see sooner than we see a cure for male pattern hair loss.