Surface modified nanoparticulate carrier constructs for oral mucosal vaccine delivery

Mucosal administration of vaccines is one of the most popular approaches to induce desired immunity against various types of antigen and microbial in central as well as peripheral blood and in most external mucosal surfaces. The oral route is a preferred choice over parenteral route for this purpose mainly due to an ease of administration and therefore, for the possibility of covering large population for mass immunization. Different strategies of mucosal vaccination aimed to prevent colony formation and infection by pathogens and block its development. But a major concern with these vaccines is the degradation of protein components in stomach due to physiological conditions and gastric enzymes. Therefore, surface modified nanoparticles offer a better and stable alternative for efficient delivery and better activation of required immune responses. Natural and synthetic polymers are used to prepare nanoparticulate carrier systems for the development of oral mucosal vaccines. Amongst these, biodegradable polymers based nano-particulate carriers have been explored extensively for the development of delivery systems. Present review summarizes possible approaches and mechanisms for the systemic immunization by oral vaccines and critically discusses various polymers used, different strategies of surface modification to achieve targeting of antigen loaded nanoparticulate carrier at cellular level that are essentially required for a successful mucosal vaccination approach, and future prospects of nanoparticulate system as adjutants in oral mucosal vaccination.