Regenerative medicine strategies for hair growth and regeneration: A narrative review of literature.

 Oct 31, 2022

Publication: Regenerative therapy

Hair loss, or alopecia, is associated with several psychosocial and medical comorbidities, and it remains an economic burden to individuals and the society. Alopecia is attributable to varied mechanisms and features a multifactorial predisposition, and the available conventional medical interventions have several limitations. Thus, several therapeutic strategies for alopecia in regenerative medicine are currently being explored, with increasing evidence suggesting that mesenchymal stem cell (MSC) implantation, MSC-derived secretome treatment, and blood-derived platelet-rich plasma therapies are potential treatment options. In this review, we searched the Cochrane Library, MEDLINE (PubMed), EMBASE, and Scopus using various combinations of terms, such as "stem cell," "alopecia," "hair loss," "Androgenetic alopecia," "male-pattern hair loss," "female-pattern hair loss," "regenerative hair growth," "cell therapy," "mesenchymal stem cells," "MSC-derived extracellular vesicles," "MSC-derived exosomes," and "platelet-rich plasma" and summarized the most promising regenerative treatments for alopecia. Moreover, further opportunities of improving efficacy and innovative strategies for promoting clinical application were discussed.

Paracrine factor Activity on hair growth
VEGF Improves perifollicular angiogenesis, resulting in increased size of HFs and shafts.
HGF Activators enhance the proliferation of follicular epithelial cells
EGF Improves the activity and growth of follicle outer-root sheath cells by activating Wnt/β-catenin flagging
PDGF and receptor Induces and maintains anagen phase of hair cycle.
IL-6 Is involved in wound-induced hair neogenesis through STAT3 activation
IGF-I Improves the migration, survival, and proliferation of HF cells
IGFBP1–6 Manage the effect of IGF-1 and its connection with ECM proteins at the HF level
TGF-β Stimulates the signaling pathways that manage the hair cycle
KGF (FGF-10) Stimulates proliferation and differentiation of early progenitor cells within HFs. Induces anagen phase in resting HFs.
FGF-1, FGF-2 Induces anagen phase in resting HFs.
bFGF Improves the advancement of HFs
BMP Maintains the DPC phenotype
BMPR1a Maintains the proper identity of DPCs
M-CSF and receptor Is involved in wound-induced hair growth
Wnt3a Is involved in HF advancement through β-catenin flagging
PGE2 Stimulates anagen in HFs
PGF2α and analogs Enhance the change from telogen to anagen.