BC-79 Removal and Desorption of Peanut (Arachis hypogaea) Allergens 1-3 Using Magnetic Nanoparticles for Application in Immunotherapy.

Peanuts are an inexpensive source of fats and proteins, but their health benefits are not available to people with an allergy (Bonku and Yu, 2020). The allergens of interest are the major allergens Ara h (Arachis hypogaea) 1-3 as they cause the most allergic reactions (Hurlburt et al., 2013). The most common peanut varieties in the US (Virginia, Jumbo Runner, and Spanish) were studied (Koppelman et al., 2016). Skinned and milled raw peanuts are defatted and proteins are extracted using carbonate buffer (pH 10.6). Magnetic iron oxide nanoparticles were coated with chitosan then tannic acid (MNP-CH-TA) and used to remove proteins from extracts. Trisaminomethane (Tris)/sodium chloride (NaCl) and sodium dodecyl sulfate (SDS) buffers were used to desorb allergens from the surface of particles. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), bicinchoninic acid (BCA) assay, enzyme-linked immunosorbent assay (ELISA) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) were used to evaluate adsorbed and desorbed proteins. Results from BCA assay show that MNP-CH-TA treated with phosphate buffer (pH 7.4) adsorbed more allergens than carbonate buffer (pH 10.6). The Jumbo Runner variety adsorbed most proteins, with a loss of 753.9 ± 29.1 µg protein per gram defatted peanut powder and the Virginia variety adsorbed the least, with 399.6 ± 145.7 µg protein per gram defatted peanut powder. According to ELISA results, SDS buffer desorbed more Ara h 3 from particles after contact with Jumbo Runner extract (93.89% [0.01 CV%]) compared to Tris/NaCl buffer (90.88% [20.29 CV%]). Future research will further focus on optimizing the allergen desorption process for application in allergen immunotherapy and particle reuse.