The dermal sheath that surrounds the outside of the hair follicle contains
progenitor cells that maintain and regenerate the dermal papilla, a key com
ponent for hair growth. Our contention is that dermal sheath cells have oth
er roles. We believe that they can become wound healing fibroblasts and per
form an important function in the repair of skin dermis after injury. The d
ermal sheath has close developmental and anatomical parallels with follicle
outer root sheath, the epithelial component that contains the stem cells r
esponsible for replacing skin epidermis. Dermal sheath cells also have a my
ofibroblast or wound healing phenotype, and in animals with high follicle d
ensities differences in wound healing are observed in conjunction with chan
ges in the hair growth cycle. Similarly, in human beings there are apparent
differences in wound healing responses between hairy and non-hairy body si
tes. Moreover, clinical and experimental data suggest that the involvement
of follicle-derived dermal cells results in qualitatively Improved dermal r
epair. Therefore, in a therapeutic context, hair follicle dermal cells prov
ide an accessible option for the creation of dermal or full skin equivalent
s that could both improve wound healing and reduce scarring. Indeed, given
the inductive properties of adult hair follicle dermal cells, it is reasona
ble to envisage a tissue engineering approach for the production of a skin
equivalent that will grow hair follicles when grafted.