Hair follicles, their disorders and their opportunities

In recent years, hair follicles have attracted much attention in several fields of research. Representing complex and dynamic three-dimensional structures, which undergo highly specific growth cycles, the hair follicles are susceptible to several disturbances, for example, infectious diseases, various forms of hair loss, autoimmune diseases, androgen-associated diseases and skin tumors. Consequently, they are increasingly considered to be relevant drug targets and to represent drug delivery routes through the stratum corneum into deeper skin layers. The effectiveness of follicular or even transfollicular penetration depends on not only the penetrating substance or on its vehicle, but also on follicular density, size and reservoir, as well as on the activity status of the hair follicle. Follicular targeting, ideally topical delivery of substances to specific compartments and cell populations within the hair follicles, offers opportunities in the treatment of hair follicle-associated diseases, immunotherapy and even gene therapy, as the bulge region of the hair follicle represents a reservoir of stem cells.This present paper gives an overview of the recent developments in the fascinating field of hair follicles, their disorders and their opportunities.

Section editor:Michael Roberts – School of Medicine, University of Queensland, Australia