Preparation and evaluation of RiVax protein loading in chitosan nanoparticles

Ricin toxin is a heterodimeric glycoprotein consists of two polypeptide chains, A and B, joined by a disulfide bond. Ricin poisoning can occur via ingestion, inhalation, or injection. Immunogenicity studies are now focused on two RTA-based subunit vaccine candidates, including RiVax and RVEc. These studies have examined the vaccine candidate immunization as an alone and in combination with adjuvant, however, there is not a published study on the immunogenicity evaluation of the candidate vaccine through the delivery by nanoparticles. The aim of this study was preparation and evaluation of RiVax Recombinant Vaccine-loading in chitosan nanoparticles.
In this experimental study, after purification of the protein by Ni-NTA chromatography column, the protein was loaded with Ionic gelation method in chitosan nanoparticles. Then physicochemical properties of nanoparticles containing RiVax and stability of this protein were evaluated during the process of loading in the chitosan nanoparticles.
Findings: The results of this study showed that the nanoparticles containing protein had a size of 178 nm and a Zeta potential of .8 MV and a PDI of 0.193. It was also found that the RiVax recombinant protein was denatured during the process of preparing the chitosan nanoparticles.
The results of this study showed that the RiVax protein has been unstable in acidic conditions for the production of chitosan nanoparticles and this method is not suitable for loading this protein in chitosan nanoparticles.