In vivo immunological activity of chitosan-derived nanoparticles

Chitosan has been studied as an immunomodulator, but few studies have used chitosan derivatives as adjuvants alone. After a preliminary study, we found that nanoparticles prepared from chitosan derivatives had better cellular immune activity when used as an adjuvant. Therefore, animal experiments were conducted to further investigate the performance and mechanism of these nanoparticles as immune adjuvants. We injected mice with the chitosan nanoparticle vaccine and measured the expression levels of immunoglobulins, immune factors, and immune genes in tissues and tissue sections. The results showed that C236-HACC-OVA (C2,3,6-chitosan sulfate-chitosan quaternary ammonium salt-ovalbumin) and NO-HACC-OVA (NO-carboxymethyl chitosan-chitosan quaternary ammonium salt-ovalbumin) nanoparticles can significantly improve the secretion of the immune factors IL-6, TNF, and IL-1β. The level of IgG1 was highly significant after administering both nanoparticles, but IgG2 was not significant in mice. Three immune factors (IL-4, IL-6, and IL-17) were secreted at high levels in mouse serum at a nanoparticle dose of 0.3 mg/mouse. These nanoparticles also have high safety in the liver, kidney, and spleen of mice. This study proves the possibility of using chitosan derivative nanoparticles as vaccine adjuvants. These data further indicate that chitosan derivative nanoparticles have potential for use as vaccine adjuvants and demonstrate that polysaccharides have a unique position in green vaccine research.