Encapsulation of Allergens into Chitosan-Alginate Nanoparticles Prevents IgE Binding
Published on: 2018-09-23
Allergens used for allergen specific immunotherapy (ASIT) can induce side effects due to the binding of IgE immobilized on mast cells to allergens. To prevent IgE binding, recombinant allergens from house dust mites (HDM) Dermatophagoides farinae Der f 2 or Aspergillus fumigatus (AF) fungi Asp f 3 were encapsulated into nanoparticles (NPs) developed from biodegradable polymers chitosan and alginate. Core NPs 400-440 nm in diameter and zeta potential +8 mV were prepared from amphiphilic chitosan derivative N-lauryl-N’-succinoylchitosan (LSC). Allergens Der f 2 or Asp f 3 were introduced during core NP formation. To mask allergens additionally, allergen loaded core NPs were coated by alginate shell. As a result of polyelectrolyte interaction between positively charged LSC and negatively charged alginic acid core-shell type NPs were formed which were 450-550 nm in diameter and zeta potential –13 to –20 mV. We demonstrated that the encapsulation of allergens into core NPs significantly decreased IgE reactivity while core–shell NPs masked the allergens completely, as was shown using IgE positive sera from patients allergic to HDMs or AF. Injection s.c. of both core and core-shell NPs into mice induced allergen specific IgG response comparable to free allergens. We concluded that encapsulation of allergens into coreshell NPs could increase the safety and preserve the efficacy of preparations for ASIT.