Engineered Iontophoresis Patch for Epicutaneous Allergen-specific Immunotherapy

Epidermal immunotherapy represents an emerging treatment method for allergic diseases. Nevertheless, an unformidable obstacle for epidermal drug delivery is the dense stratum corneum of the skin. Here, iontophoresis technology is utilized for epidermal delivery of allergen protein. Briefly, an iontophoresis patch consists of conductive nanofiber polypyrrole (PPy) and polyvinyl alcohol (PVA) by electrospinning technology, onto which cationic lipid dioctadecyl–dimethylammonium bromide vesicles containing ovalbumin (DDA@OVA) are loaded via electrospraying technology, forming a stable in situ composite structure. Compared with DDA@OVA/PVA, DDA@OVA/PPy-PVA demonstrated a significant increase in both allergen release and penetration into the epidermis. Ultimately, a high-level activation of antigen-presenting cells is facilitated. Importantly, DDA@OVA/PPy-PVA induces a significant increase in the levels of helper T cell 1 (Th1)-related cytokines such as IFN-γ and IL-12, inhibits the differentiation of T cells into Th2 cells, and further affects the secretion of OVA-specific IgE and promotes the production of protective antibody IgG. The lung tissue analysis illustrates that DDA@OVA/PPy-PVA treatment achieves regular alveolar structures in the lumen and significantly relieved asthma symptoms. The findings indicate that iontophoresis patches provide multiple benefits, including drug-responsive release, efficient penetration, and advanced therapeutic efficacy. These attributes make iontophoresis patches a promising treatment option for allergic diseases.