Therapeutic strategy for hair regeneration: hair cycle activation, niche environment modulation, wound-induced follicle neogenesis, and stem cell engineering

Abstract

Introduction: There are major new advancements in the fields of stem cell biology, developmental biology, regenerative hair cycling, and tissue engineering. The time is ripe to integrate, translate, and apply these findings to tissue engineering and regenerative medicine. Readers will learn about new progress in cellular and molecular aspects of hair follicle development, regeneration, and potential therapeutic opportunities these advances may offer.

Areas covered: Here, we use hair follicle formation to illustrate this progress and to identify targets for potential strategies in therapeutics. Hair regeneration is discussed in four different categories: i) Intra-follicle regeneration (or renewal) is the basic production of hair fibers from hair stem cells and dermal papillae in existing follicles. ii) Chimeric follicles via epithelial–mesenchymal recombination to identify stem cells and signaling centers. iii) Extra-follicular factors including local dermal and systemic factors can modulate the regenerative behavior of hair follicles, and may be relatively easy therapeutic targets. iv) Follicular neogenesis means the de novo formation of new follicles. In addition, scientists are working to engineer hair follicles, which require hair-forming competent epidermal cells and hair-inducing dermal cells.

Expert opinion: Ideally self-organizing processes similar to those occurring during embryonic development should be elicited with some help from biomaterials.

Keywords::

• alopecia
• biomaterials
• dermal papilla
• regenerative medicine
• stem cells
• tissue engineering
• wound
• wound healing

Acknowledgement

This work is supported by NIH NIAMS grant AR 60306 (CMC, TXJ); 42177 (CMC), 47364 (CMC, RW). Additional support is from the Industrial Technology Research Institute, Hsinchu, Taiwan (SCC, CCC, TXJ, LMW) and a collaborative grant between Taiwan University/Yang Ming University (SJL and CCC). SJL is supported by a physician scientist fellowship from National Health Research Institutes (NHRI), Taiwan (PS9803) when he was at USC and by Taiwan National Science Council (NSC99-2320-B-002-004-MY3 and NSC101-2325-B-002-081). MXL is supported by a fellowship from the China Scholarship Council.

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