Potential of Hair Follicle Stem Cell-Derived Exosomes Carrying miR-181a-5p to Promote the Telogen-to-Anagen Stage.

backgroundHair loss is a common clinical and aesthetic concern, and existing treatments remain limited by side effects, invasiveness, or unsatisfactory long-term efficacy. Stem cell-derived exosomes have emerged as a promising cell-free strategy for tissue regeneration. However, the hair-regenerative potential of hair follicle stem cell-derived exosomes (HFSC-Exos), particularly when enriched with miR-181a-5p, remains insufficiently explored.

methodsCommercially available rat hair follicle stem cells (HFSCs) were cultured, and exosomes were isolated from cells at passages 3-4 after transfection with miR-181a-5p mimics or negative control mimics. Exosomes were characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and western blotting. Twenty 7-week-old C57BL/6 mice, which were generally in telogen at this age, were randomly assigned to four groups (n = 5/group): PBS, Exos, Exos

resultsHFSC-Exos accelerated the transition from telogen to anagen and promoted visible hair regrowth compared with PBS treatment. Among all groups, Exos

conclusionHFSC-Exos promoted the telogen-to-anagen transition and hair regrowth in vivo. Enrichment of miR-181a-5p enhanced this effect and was associated with activation of the Wnt/β-catenin pathway, although direct target validation remains to be established. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .