Engineering the niche for hair regeneration — A critical review

Recent progress in hair follicle regeneration and alopecia treatment necessitates revisiting the concepts and approaches. In this sense, there is a need for shedding light on the clinical and surgical therapies benefitting from nanobiomedicine. From this perspective, this review attempts to recognize requirements upon which new hair therapies are grounded; to underline shortcomings and opportunities associated with recent advanced strategies for hair regeneration; and most critically to look over hair regeneration from nanomaterials and pluripotent stem cell standpoint. It is noteworthy that nanotechnology is able to illuminate a novel path for reprogramming cells and controlled differentiation to achieve the desired performance. Undoubtedly, this strategy needs further advancement and a lot of critical questions have yet to be answered. Herein, we introduce the salient features, the hurdles that must be overcome, the hopes, and practical constraints to engineer stem cell niches for hair follicle regeneration. In a hair follicle, keratinocytes and melanocytes respectively originate from the surface ectodermal and neuroectodermal embryonic layers. The origin of the dermis is dependent on its location in the body. The face and scalp dermis is developed from neural crest. Thus, hair follicle dermal papilla, dermal sheath, and mesenchymal cells are also formed from neural crest. Nanomedicine is able to facilitate hair follicle regeneration by stimulating specific cells. Nanomedicine offers a platform for the incorporation of useful biological molecules for the regeneration of hair follicle. It is expected that this growing technology will play a critical role in the advancement of hair regeneration in the near future. [Display omitted]