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

Area of Science:

• Biomaterials Science
• Dermatology
• Immunology

Background:

• Hair loss is a common condition with few effective treatments.
• The hair follicle immune microenvironment plays a critical role in hair regeneration.
• Current treatments for hair loss are limited in efficacy.

Purpose of the Study:

• To develop a novel cold atmospheric plasma (CAP)-activated in situ hydrogel for hair regeneration.
• To investigate the mechanism by which the hydrogel modulates the hair follicle immune microenvironment.
• To evaluate the efficacy of the hydrogel in a mouse model of hair loss.

Main Methods:

• Formation of a CAP-activated hydrogel (CAPgel/IL2) from a tyramine-grafted hyaluronic acid solution containing interleukin-2 (HTsol/IL2).
• In situ hydrogel formation via subcutaneous injection and subsequent CAP exposure in mice.
• Assessment of hair regeneration, hair follicle morphology, and skin thickness in a depilated mouse model.
• Analysis of regulatory T cell (Treg) expansion and skin pigmentation changes.

Main Results:

• CAPgel/IL2 treatment significantly promoted hair regeneration in mice compared to control groups.
• Enlarged hair follicles and a thickened hypodermis were observed in CAPgel/IL2-treated mice.
• Prolonged retention of IL2 in the hydrogel led to increased Treg expansion within the hair follicle microenvironment.
• Accelerated skin pigmentation changes indicated a shift from telogen to anagen phase.

Conclusions:

• The CAP-activated hydrogel (CAPgel/IL2) effectively promotes hair regeneration by enhancing Treg expansion in the hair follicle microenvironment.
• This novel hydrogel represents a potential therapeutic strategy for treating hair loss.
• The CAP-activated IL2 delivery approach may also be applicable to other immune-related skin disorders.