Engineered Collagen XVII-Loaded Dissolving Microneedle Patch for Promoting Hair Regrowth in Androgenic Alopecia

The study investigates the role of collagen XVII (COL17) in androgenic alopecia (AGA) and introduces a novel treatment using a dissolving microneedle (MN) patch loaded with recombinant human COL17 fragment (rhCOL17p). In a testosterone-induced AGA-like mouse model, COL17 was significantly downregulated, leading to abnormal hair follicle morphology and impaired hair growth. The rhCOL17p-MN patch, designed for effective transdermal delivery, achieved 96% skin penetration and demonstrated comparable efficacy to 5% minoxidil, with 97% hair coverage by day 14. The treatment enhanced follicle density, anagen-phase transition, and vascularization, while also activating stem cell and proliferative signaling pathways. The patch showed low hemolysis and strong mechanical stability, indicating its safety and potential as a promising AGA treatment.