Lipid nanoparticles as delivery vehicles for the Parietaria judaica major allergen Par j 2

Maria Luisa Bondì^1,*, Giovanna Montana^2,*, Emanuela Fabiola Craparo³, Roberto Di Gesù³, Gaetano Giammona³, Angela Bonura², Paolo Colombo^2
1Istituto per lo Studio dei Materiali Nanostrutturati, ²Istituto di Biomedicina ed Immunologia Molecolare, Consiglio Nazionale delle Ricerche, ³Laboratory of Biocompatible Polymers, Dipartimento di Scienze e Tecnologie Molecolari e Biomolecolari Stembio, Università di Palermo, Palermo, Italy
^*These authors contributed equally to this work

Abstract: Parietaria pollen is one of the major causes of allergic reaction in southern Europe, affecting about 30% of all allergic patients in this area. Specific immunotherapy is the only treatment able to modify the natural outcome of the disease by restoring a normal immunity against allergens. The preparation of allergen-solid lipid nanoparticles as delivery vehicles for therapeutic proteins, P. judaica major allergen Par j 2, was investigated. The Par j 2 allergen was expressed in a large amount in Escherichia coli and purified to homogeneity. Its immunological properties were studied by western blotting and enzyme-linked immunosorbent assay inhibition. Solid lipid nanoparticles were obtained by water-in-oil-in-water multiple emulsion method and characterized in terms of mean size and surface charge. These systems (approximately 250 nm diameter and negative surface charge) incorporated recombinant Par j 2 with 40% or greater efficiency. Moreover, the endotoxin level and anaphylactic activity of the empty solid lipid nanoparticles and recombinant Par j 2-loaded solid lipid nanoparticles were evaluated by looking at the overexpression of CD203c marker on human basophils. These results demonstrate that recombinant Par j 2-nanoparticles could be proposed as safe compositions for the development of new therapeutic dosage forms to cure allergic reactions.

Keywords: solid lipid nanoparticles, Parietaria judaica (Par j), drug delivery, recombinant allergens, specific immunotherapy, allergic rhinitis