Delivery of Allergen Powder for Safe and Effective Epicutaneous Immunotherapy

Abstract Background More effective and safer immunotherapies to manage peanut allergy are in great demand despite extensive investigation of sublingual/oral (SLIT/OIT) and epicutaneous (EPIT) immunotherapies currently in the clinics. Objective To develop a powder-laden, dissolvable microneedle array (PLD-MNA) for epidermic delivery of powdered allergens and to evaluate efficacy of this novel EPIT in peanut-sensitized mice. Methods PLD-MNA was packaged with a mixture of powdered peanut allergen (PNA), vitamin-D3 (VD3), and CpG. Its epidermic delivery and therapeutic efficacy were evaluated, alongside PNA-specific Foxp3+T regulatory (Treg) cells and IL-10+ and TGF-β1+ skin-resident macrophages. Results PLD-MNA was successfully laden with PNA/VD3/CpG powder and capable to epidermically deliver most of its content one hour after applied onto intact mouse skin, concomitant with no significant leakage into the circulation or skin irritation. PLD-MNA-mediated EPIT substantially reduced clinical allergy scores to 1, from 3.5 in sham controls (p Conclusions PLD-MNA holds great promise as a novel, safe, effective, and self-applicable modality to manage IgE-mediated allergies.