ABSTRACT
Nanoparticles administered intramuscularly (IM) or subcutaneously (SC) are expected to remain essentially at the site of administration and control the release of the loaded antigen. Nanoparticles of poly(methylmethacrylate) were claimed to be biodegradable after SC or IM injection and shown to exhibit very powerful adjuvant properties for a number of antigens. The most attractive, easiest, and most acceptable route for mucosal immunization is the oral one. Comparing polyethylene glycol (PEG)-nanoparticles with chitosan-coated nanoparticles, it was observed that PEG-nanoparticles were more efficient than chitosan-coated nanoparticles in facilitating the transport of the associated antigen through the mucosa. In mice, nasal immunization with herpes simplex virus type-2 glycoprotein in calcium phosphate nanoparticles induced protective immunity against an intravaginal challenge. In mice, oral immunization with poly(lactide-co-glycolide) nanoparticles has been shown to induce potent mucosal and systemic immunity to entrapped antigens. In any case, it appears that “conventional” nanoparticles offer a limited ability as adjuvants for oral vaccination.
