Male and female pattern baldness involves the receding of the hair-line, hair loss and the thinning the hair covering on the scalp. Hair loss is also called alopecia and is a common problem among the elderly, those afflicted with certain diseases of the scalp, or those who take certain medicines. Hair life is not the end of life, but it can change someone’s appearance, affect their self-image, and affect someone’s emotional state. People with hair loss can use topical monoxidil (Rogaine), take an oral drug called finasteride (Propecia), or undergo a hair transplant. The drugs, however, must be used constantly or they stop working and hair transplants are horribly expensive.
Can stem cell-based treatment restore hair after it has been lost? Fortunately, a stem cell population called dermal papilla cells (DPCs), which are a type of mesenchymal stem cell population in hair follicles, have been identified and even characterized to some extent. DPCs are responsible for the formation of hair-follicles and play a very role in the process of hair cycling in which the hair shaft grows, is shed, is reestablished, and grows again. DPC might be useful for treating alopecia, but they do not survive when cultured outside the body, and this limitation has limited developing stem cell-based treatments for hair loss.
Now collaboration between two scientific research teams from Canada and China have resulted in a new way to use stem cells to treat hair loss.
A research team from the Nanfang Hospital of Southern Medical University, China, led by Zhi-Qi Hu and a Canadian team from the University of Manitoba, Canada, led by Malcolm Xing have designed a three-layered tunic that feeds and protects the DPCs and allows them to grow outside the body.
Xing describes this nutritive tunic as a “nutritious nano-clothing,” made of gelatin and alginate. These molecules can self-assemble and Hu and Xing and their coworkers encapsulated the cells within an inner layer of gelatin, a middle layer of alginate loaded with fibroblast growth factor-2, and an outer layer of gelatin. They call this method of encapsulation “layer-by-layer (LBL) nano-coating.” This gelatin/alginate coating creates a protective microenvironment for cultured DPC and provides them with a significant source of a growth factor called fibroblast growth factor-2 (FGF2), which enhances proliferation of the DPCs and induces hair cell fates. The use of these three-layered tunics keeps the inductive signals close to the DPCs and circumvents the difficulties encountered in regenerating new hair follicles on bald skin.
When the Xing and Hu teams implanted these encased DPCs into the skin of nude mice, the implanted encapsulated cells generated the growth of abundant hair. The hair produced by these cells also was rooted in hair follicles that were normal in their appearance and function. The coating improvised by these teams greatly augmented the therapeutic capabilities of the DPCs by recapitulating the niche in which these cells are normally found. This stem cell niche induces the cells to secrete the native extracellular matrix that typically surrounds the cells and release the growth factors that keep the cells growing and in the proper stage of the cell cycle.
According to Xing, the most difficult part of this research project was “optimizing the concentrations of the coated polymers and manufacturing conditions to make the cells happy and healthy.”
Regenerative medicine researcher Oommen Varghese, from Uppsala University in Sweden, who was not involved in this work, said, “This is fascinating science that has enormous potential for clinical translational of stem cell based regenerative medicine. Such a coating could also protect cells from innate immunity, thereby improving the in vivo survivability. This is a major challenge in stem cell based translational research.”
Xing and his collaborators and colleagues would like to transform this technique from a laboratory bench to a clinical application that can be tested in human clinical trials.