Fig. 6.

(A) Schematic illustration of a PLGA hollow nanoparticle encapsulating CpG (CpG-NP). And CpG (CpG-NP) showed results of more effective and long-lasting immune activation in chBMDCs [67]. (B) The synthetic route to CD-PEI conjugates and a CD-based mRNA vaccine platform [86,87]. (C, a) Preparation of viromimetic nanoparticle vaccine. Hollow PLGA nanoparticles with encapsulated adjuvant and surface maleimide linkers were prepared using a double emulsion technique. Recombinant viral antigens were then coupled to the surface of nanoparticles via thiol-maleimide bonds. Synthetic viral-like nanoparticles facilitate coordinated delivery of antigens and adjuvants in vitro and in vivo. (b) Viromimetic nanoparticle induces robust and long-lasting humoral and CD4⁺ T cell responses. (c) Viral-like nanoparticles vaccine grants protection against MERS-CoV infection in DPP4-transplanted mice [68].