title: Therapeutic strategy for hair regeneration: hair cycle activation, niche environment modulation, wound-induced follicle neogenesis, and stem cell engineering.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  Ideally self-organizing processes similar to those occurring during embryonic development should be elicited with some help from biomaterials.
authors.affiliation: Industrial Technology Research Institute, Hsinchu, Taiwan.
authors.forename: Shan-Chang
authors.initials: SC
authors.lastname: Chueh
authors.forename: Sung-Jan
authors.initials: SJ
authors.lastname: Lin
authors.forename: Chih-Chiang
authors.initials: CC
authors.lastname: Chen
authors.forename: Mingxing
authors.initials: M
authors.lastname: Lei
authors.forename: Ling Mei
authors.initials: LM
authors.lastname: Wang
authors.forename: Randall
authors.initials: R
authors.lastname: Widelitz
authors.forename: Michael W
authors.initials: MW
authors.lastname: Hughes
authors.forename: Ting-Xin
authors.initials: TX
authors.lastname: Jiang
authors.forename: Cheng Ming
authors.initials: CM
authors.lastname: Chuong
mesh_terms: D000818:Animals; D060846:Cell Engineering; D006197:Hair / Q000254:growth & development* / Q000378:metabolism; D018859:Hair Follicle / Q000254:growth & development*; D006801:Humans; D044968:Regenerative Medicine; D012867:Skin / Q000293:injuries*; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D014945:Wound Healing