RiVax Loaded ALG Nanoparticles: Physicochemical and Immunological Characterization

Ricin is a toxic glycoprotein, it consists of two subunits (RTA&RTB). There are two vaccine candidates based on RTA included RiVax and RVEc. Although different studies about immunized potency of RiVax, alone and with adjuvant, have been performed, but novel delivery system like nanoparticles to improve immunization of this protein has not been used until today. The purpose of this study was the synthesis of alginate nanoparticles (NPs) containing RiVax and evaluation of physicochemical parameters and immunization potential of this system as compared to naked RiVax. In this research, after purification of RiVax, Ionic gelation method was used to prepare alginate nanoparticles, which is a simple and suitable method for heat sensitive materials.Then, NPs containing RiVax and naked protein was administrated into different groups of mice. 8weeks after last immunization, the mice were analyzed. Results showed that the size of NPs was 190nm and the release pattern of protein from nanoparticle is slow (12%of protein during 40days). Also, immunization results showed that NPs containing RiVax compared to naked RiVax could not stimulate the immune system interestingly. We concluded that the alginate NPs could not be able to make a remarkable immune response compared to protein alone due to the slow release of RiVax from them.