Microfold-cell targeted surface engineered polymeric nanoparticles for oral immunization.

Present work was envisaged to develop novel M-cell targeted polymeric particles that are capable of protecting the antigen from harsh gastric conditions. Ulex europaeus agglutinin (UEA-1) lectin was anchored for selective delivery of antigen to gut-associated lymphoid tissue (GALT). In the present investigation, chitosan nanoparticles were prepared by ionic gelation followed by antigen (bovine serum albumin, BSA) adsorption. Developed nanoparticles were further coated by UEA-1 lectin conjugated alginate and characterized for size, shape, zeta-potential, entrapment efficiency, and in vitro release. The immunological response of the developed system were performed in Balb/c mice and compared with aluminium hydroxide gel-based conventional vaccine. Results indicated that immunization with UEA-1 lectin conjugated alginate-coated particles induces efficient systemic as well as mucosal immune responses against BSA compared to other formulations. Aluminium-based vaccine dominated throughout the study, while failed in case of mucosal antibody. Additionally, IgG1 and IgG2a isotypes were determined to confirm the TH1/TH2 mixed immune response. The developed formulation exhibited superior systemic response along with dominating mucosal immunity. These data demonstrate the potential of UEA-alginate-coated nanoparticles as effective delivery system via oral route.