Hair morphogenesis in vitro:: formation of hair structures suitable for implantation

Aim: To develop a construct through which implanted follicular cells will efficiently cause hair regeneration for the treatment of androgenetic alopecia. Materials & methods: Follicular dermal and epidermal cells isolated from embryonic mouse skin were formed into aggregates. The aggregates were incubated in culture for 5-7 days and then implanted intradermally into athymic mice. Results: During culture, mixed cell aggregates developed into hair-like structures, termed 'proto-hairs'. Proto-hairs contained structures that resembled normal hair components, such as dermal papillae, hair matrix and rudimentary hair shafts. When implanted into mouse skin, they developed further into mature hair follicles capable of prolonged growth. Conclusion: Mixed aggregates of murine follicular cells have the ability to develop in culture into proto-hairs that retain the ability to fully develop into hair follicles after implantation. Proto-hairs from human cells could provide a convenient and practical means by which follicular cells could be implanted for efficient hair regeneration to treat hair loss.