In Vitro Characterization of Chitosan-Based Particles as Carrier of Influenza Viral Antigens

DOI : 10.26650/EurJBiol.2018.0004 Objective : Chitosan is a natural polysaccharide derived from chitin by deacetylation. It is a non-toxic, biocompatible and biodegradable polymer, and has attracted considerable interest in a wide range of pharmaceutical applications including drug and vaccine delivery. The immune-stimulating activity of chitosan microparticles such as the activation of macrophages and polymorphonuclear leukocytes has been reported. In this work, we have investigated the releasing properties of influenza virus antigens from the chitosan microparticles and beads. Materials and Methods : Chitosan microparticles and beads were prepared by coacervation and ionotropic gelation method, respectively. The microparticles and beads were loaded with the viral antigens by passive adsorption and/or entrapment into the microparticles. The titration of the viruses was defined by haemagglutination assay or by quantitation of viral proteins using the Bradford method. Results : The results showed that the loading efficiency and the loading capacity of chitosan microparticles/beads with the viral antigens and the releasing profiles of the antigens from the particles changed depending on the type of chitosan, the pH of the loading buffer and the methods used to prepare the particles. The influenza viral antigens, passively adsorbed onto microparticles/beads, were released within 2 hours to 5 days. In contrast, the viral antigens entrapped into the chitosan microparticles were released more slowly and continued for up to 30 days. Conclusion : It was concluded from the viral antigen releasing profiles of chitosan particles that the viral antigens entrapped into the microparticles are more suitable for in vivo applications as a potential mucosal vaccine.