The present invention relates to a core-shell nanoparticle, wherein the core is solid and comprises a zein matrix and a basic amino acid； and the shell comprises a conjugate obtained by reaction of a poly (methyl vinyl ether-co-maleic anhydride) copolymer with a compound having a reactive primary amine group. It also relates to a process for their preparation as well as their use in immunotherapy and in the treatment of disease, such as diabetes.
