Hair follicle: A novel source of stem cells for cell and gene therapy

The adult body harbors powerful reservoirs of stem cells that enable tissue regeneration under homeostatic conditions or in response to disease or injury. The hair follicle is a readily accessible mini organ within the skin and contains stem cells from diverse developmental origins that are shown to have surprisingly broad differentiation potential. In this chapter, we discuss the biology of the hair follicle with particular emphasis on the various stem cell populations residing within the tissue. We summarize the existing knowledge on putative hair follicle stem cell markers, the differentiation potential, and technologies to isolate and expand distinct stem cell populations. We also discuss the potential of hair follicle stem cells for drug and gene delivery, tissue engineering, and regenerative medicine. We propose that the abundance of stem cells with broad differentiation potential and the ease of accessibility make the hair follicle an ideal source of stem cells for gene and cell therapies.