I came across a pretty interesting press release last week from a Vancouver based company called RepliCel. They've been working on a new type of treatment for hair loss that involves using somatic stem cell injections to grow new hair follicles as a treatment for balding conditions like Male Pattern Baldness (MPB).
Many people will experience some degree of hair loss over the course of their lives, and for a good number, it doesn't really matter, baldness just goes with aging (I begrudgingly lump myself into this category!) . There have been several hypotheses put forward adressing the evolutionary reasons behind balding with some suggesting that it denotes the age of an individual and confers authority. One idea that I came across a while back proposed that the enlarged forhead of a bald male would permit a larger and more noticeable blush response when angered, allowing him to scare off other primates...
Irrespective of it's cause, balding is typically cast in a poor light in our culture (not to say that there are none immune to this, Patrick Stewart ftw!!!). Popular culture tells us that hair loss is unattractive and even abnormal, particularly in younger people which has resulted in a massive industry centered on curing (or hiding) it. Some of the current popular treatments are Finasteride (system-wide inhibition of dihydrotestosterone production... kind of scary in my opinion), Minoxidil (whose mode of action is still a bit of a mystery and isn't all that effective) and follicular unit transplantation (just as it sounds; healthy follicular units are transplanted from a donor region to a baldness affected recipient region - this technique is unfortunately limited by the number of healthy donor follicles available and is pretty expensive). From what I've seen, none of these treatments represent a long term or even relatively effective treatment option and they'll soon be outdone by modern stem cell transplantation technologies like the one being developed by RepliCel.
The founders of RepliCel published a paper back in 2003 where they demonstrated the basic principles behind their technology. Healthy follicles were isolated from mice and dissected to yield small pieces of tissue from the dermal pappila and dermal sheath cup (both are regions at the base of the hair follicle thought to house progenitor cells that can regenerate the follicle). They cultured the cells to expand their numbers and subsequently implanted them into hairless regions on mice in hopes of achieving new follicle and hair growth. They made two very exciting observations from their experiment: firstly, the implanted cells did indeed promote new follicle and hair formation and secondly, the implanted cells also seemed to be able to migrate to damaged or dormant hair follicles and revitalize them. Pretty awesome stuff right?
A lot of research has been done in this field since that time. One paper that I read recently by Toyoshima et al. demonstrated that follicles derrived from implanted stem cells formed connections with surrounding nerve fibers and muscle resulting in a follicle that was very similar to those formed over the course of normal development. The researchers cleverly used a nylon thread implanted along with the cells (they injected cells into very shallow stab wound and placed a small nylon thread in so that it was perpendicular to the plane of the skin and extending approximately from the point of cell implant to outside of the skin) to help direct the structuring of the follicle. This might also be a great way to control the direction of follicle and hair growth allowing for quick and easy bioabsorbable, stem cell laden implants.
The above experiments were all conducted in mice mind you, but RepliCel has recently abnnounced positive results from their “in-man” human phase I trials. I haven't seen too many details other than a statement claiming safety and efficacy (could you be a little more vague please?) but they're moving along to phase II trials soon and researchers around the world continue to make progress in this and related fields. The concept has been proven, now someone just needs to work out the kinks.