The Dermal Papilla and Hair Follicle Regeneration: Engineering Strategies to Improve Dermal Papilla Inductivity

Introduction: The Dermal Papilla (DP) has been the focus of many studies regarding the hair follicle due to its critical role in morphogenesis, hair cycling, and de novo induction. These studies have led to the current ambition of harnessing DP cells to provide a clinical cell-based therapy which overcomes the major limitation in hair follicle transplantation, a lack of donor material. Methods: Revision of peer-reviewed published literature using different databases including Pubmed. Results: Early work using explanted DP demonstrated a capacity to induce de novo hair follicles at implantation sites. In order to overcome limited donor material, cells need to be expanded in vitro. However, DP cells lose their inductive potential when cultured. In order to address this issue, researchers have attempted to maintain, restore, and improve inductivity in a number of ways. The most successful of these studies to date have combined elements of the 3 pillars of Tissue Engineering: Cells, Signals and Scaffolds. Conclusions: In the past, most approaches have utilised single pillar approaches in order to improve DP inductivity with limited success. More recent bioengineered solutions which are carefully designed to factor all three pillars of tissue engineering are starting to show real promise. Challenges remain, largely surrounding the quality of induced hair follicles and the efficiency to which they are induced as well as time and cost to deliver these therapies. However, if these issues can be overcome, tissue engineered hair follicle restoration would present a significant step-change in hair follicle restoration.