摘要

Objectives: To review the role of hair follicle stem cell (HFSC) dynamics in hair loss and summarize current and emerging stem cell–based therapeutic strategies relevant to trichology Introduction: Hair follicle homeostasis and regeneration depend on adult stem cell niches, primarily HFSCs located in the bulge region of the outer root sheath. These cells are regulated by their microenvironment and key signaling pathways, notably Wnt. Aging disrupts HFSC function through prolonged quiescence, niche degradation, inflammation, and fibrosis, leading to impaired regeneration, follicular miniaturization, and clinical hair loss, particularly in androgenetic alopecia (AGA). Materials / method: This presentation is focusing on HFSC biology, mechanisms of hair follicle aging, and stem cell–based therapies for hair loss. HFSC activation and aging, inflammatory and fibrotic niche alterations in AGA, and therapeutic approaches such as autologous stem cell transplants (nanofat, stromal vascular fraction, Rigenera®), exosome-based therapies, and platelet-rich plasma (PRP) will be addressed, with attention to mechanisms of action and regulatory considerations. Results: Autologous adipose-derived stem cell therapies (nanofat and SVF) have demonstrated promising clinical outcomes, with SVF showing greater efficacy than nanofat. Rigenera® technology has shown a reported increase in hair density in treated AGA areas. Exosomes act as potent paracrine modulators of HFSC activity and follicle regeneration, though safety, standardization, and regulatory oversight remain debated. PRP promotes hair growth through growth factor–mediated HFSC stimulation and is widely used as an off-label, autologous procedure. Conclusion: -HFSC dysfunction driven by aging and niche alteration is central to hair loss pathogenesis. Stem cell–based and regenerative therapies represent promising aesthetic interventions, but variability in efficacy, safety concerns, and regulatory limitations underscore the need for further standardized clinical studies.