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. |