Fig 5.

Different mucosal vaccine delivery systems. (A) Scanning electron micrograph of poly(lactic-co-glycolic acid) microparticles [94], (B) scanning electron micrograph of polyanhydride nanoparticles [111], (C) transmission electron micrograph of chitosan : poly-γ-glutamic acid nanoparticles [129], (D) transmission electron micrograph of gold nanoparticles [136], (E) transmission electron micrograph of silica nanoparticles [135], (F) transmission electron micrograph of mannose and monophosphoryl lipid A decorated cationic liposomes [138], (G) transmission electron micrograph of influenza virus-like particles [139], (H) scanning electron micrograph of lycopodium spores (pollens) [140]. Images reproduced with permission of the respective publishers.