Current Advances in Stem Cell-Based Therapies for Hair Regeneration

The document from August 2020 reviewed the progress in stem cell-based therapies for hair regeneration, focusing on the use of conditioned medium (CM) and exosomes. Alopecia, prevalent due to hereditary factors, stress, and psychiatric disorders, can be divided into nonscarring and scarring types. Nonscarring alopecia, including androgenetic alopecia (AGA), is reversible as hair follicle stem cells (HFSCs) are preserved. Three therapeutic mechanisms were identified for hair regeneration using stem cells: reversing hair loss pathogenesis, regenerating hair follicles with "bulge", and creating new hair follicles from stem cell culture. The secretome, substances secreted by stem cells, plays a critical role in these processes. The CM, a nutrient medium containing the secretome, has shown positive effects on hair regeneration. Exosomes, the smallest type of extracellular vesicles, can deliver functional elements to target cells, triggering regeneration. Despite promising outcomes, challenges remained in mass production and clinical application of these therapies.