Hair growth is maintained through a cyclic process that includes a periodic stem-cell-dependent regeneration of hair follicles. The hair cycle consists of three defined stages: growth (anagen), followed by regression (catagen) and rest (telogen). Growth of a new hair requires reentry into anagen, a process involving activation of multipotent epithelial stem cells residing in a specialized part of the follicle outer root sheath (ORS) known as the bulge. Activating signals emanate from adjacent mesenchymal cells (dermal papilla), directing epithelial stem cells to migrate and differentiate to regenerate the hair bulb, the structure from which a new hair will emerge. Multiple signaling pathways, including Wnts, Sonic hedgehog (Shh), and TGF-beta family members have been shown to promote anagen initiation.
Androgenetic alopecia (AGA) is characterized by the structural miniaturization of androgen-sensitive hair follicles in susceptible individuals and occurs in an anatomically defined pattern on the scalp. Hair loss in aging men is characterized by these “damaged hair follicles.” Normal hair growth depends on the hair cycle where periodic regeneration of a tiny organ, the hair follicle, occurs through a stem-cell-mediated process. Within the follicle normal stem cell function is essential for hair follicle regeneration. In their studies of wound healing in burn victims and ulcer patients, Drs. Al-Qahtani and Maguire observed the formation of new follicles and associated new hair growth. The formation of new follicles and hair growth was shown to be associated with a cascade of cellular and biochemical events during the wound healing process.
By studying wound healing at the cellular and molecular levels, the skin was observed to have the ability to revert to a more primitive or “embryonic” state as progenitor cells migrate to the wounded area, restoring the regenerative capacity of the skin not previously thought to occur in adults The regenerative response included new hair follicle formation, allowing new hair to grow at the restored site. A major part of the wound healing cascade is the release of growth factors and cytokines from stem cells into the layers of the scalp at the site of the wound.
Although dihydrotestosterone (DHT) is only one factor, and a minor factor, in causing the unhealthy minaturization of the follicle in male pattern baldness, this process has received much attention. Several products are now on the market that attempt to restore hair growth based on interacting with the DHT pathway. These DHT specific products (e.g. Finasteride) have demonstrated limited efficacy and debilitating side-effects, including sexual dysfunction. Growth factors have also previously been shown to overcome the metabolic processes associated with benign prostrate hyperplasia (BPH). Based on the similar etiologies of BPH and of male pattern baldness through a dihydrotestosterone (DHT), we hypothesized that naturally occurring growth factors may also benefit the treatment of AGA through the DHT pathway, but without the side-effects seen with other products such as minoxidil, a potassium channel agonist that effects heart function, and the previously mentioned Finasteride . More importantly, the direct effects of topically applied cytokines and growth factors to the biochemical milleu of the follicle to restore the normal physiology and anatomy of the hair follicle is the crtical factor in restoring hair growth.
Here, we report the first example of a placebo-controlled, double-blind study undertaken to examine the benefit of these naturally occurring growth factors in the treatment of AGA.
Objectives: The goal of this study was to test naturally occurring growth factors in the treatment of AGA.
Subjects: Included in this study were males between the ages of 25 and 65 years of age, in good health, with mild to moderate AGA.
Efficacy measurements were administered at baseline, and then at a final visit. The measurments were: 1) investigative staff assessed hair growth and 2) patient self-assessment of treatment efficacy and satisfaction with appearance.
The parameters assessed by study subjects in this analysis were the following questions: a) size of bald spot; b) appearance of hair; c) growth of hair; d) rate of hair loss; and e) satisfaction with appearance of hair.
The results of this study showed a highly positive response to treatment. The blinded investigative staff assessment report showed that over 90% of study subjects dosed with the active study formulation were rated as improved at the final visit. Patient self assessment demonstrated that 94% of the patients saw significant improvement in hair growth and prevention of hair loss. Although color of the new hair was not quantified, most subjects reported and were observed in the clinic to have new hair growth that expressed the hair’s natural color.
Conclusions: This study establishes the effectiveness of naturally occurring growth factors for the first time in the treatment of hair loss.
Growth factor technology has been used to generate completely new hair follicles for the first time in normal adult males.
The researchers were able to induce the regenerative response, including new hair follicle formation, by applying a combination of factors to the scalp. This work showed that the induction of this primitive state in skin triggered corresponding embryonic molecular pathways distinct from those active in corresponding cells in adult skin, allowing a new topical treatment option for regrowing hair not previously thought to have therapeutic benefit in normal adult skin.