Determinants of the direction of hair follicle growth after reconstruction with dissociated cells

Abstract

Several hair follicle reconstruction models based on the implantation of dissociated cells have been established. However, little has been said about the direction of growth, which is a very important issue for clinical applications. The aim of this study was to reveal the factors that determine the direction of hair follicle growth after reconstruction with dissociated cells. We designed an enclosed chamber assay in which a chamber was buried under nude mouse skin that was not exposed to the air, as in a traditional chamber assay. Inductive dermal cells and epithelial cells dissociated from neonatal C57 BL/6 mice were injected into the chamber and dermis for patch assays. The direction of newly formed hair follicles was analysed. Newly formed hair follicles in the enclosed chamber were arranged randomly parallel to the skin on the surface of the panniculus carnosus. These results indicate that developmental space provides the possibility for growth of reconstructed hair follicles and that the air-liquid interface determines the final direction of growth.