Cold Atmospheric Plasma-Activated In Situ Hydrogel Induces Hair Regeneration Via Immune Microenvironment Remodeling

The study investigates a novel treatment for hair loss using a cold atmospheric plasma (CAP)-activated in situ hydrogel, which modulates the immune microenvironment of hair follicles to promote hair regeneration. The hydrogel, formed by CAP irradiation of a tyramine-grafted hyaluronic acid solution containing interleukin-2 (IL2), retains reactive oxygen species and IL2. In a depilated mouse model, this treatment significantly enhances hair regeneration, characterized by enlarged hair follicles and a thickened hypodermis, compared to other groups. The hydrogel's prolonged retention of IL2 increases regulatory T cell expansion within the hair follicle microenvironment, accelerating the transition from the telogen to the anagen phase. These results suggest that the CAPgel/IL2 could be a promising treatment for hair loss and potentially other immunologic skin disorders.