Alginate-coated chitosan nanogels differentially modulate class-A and class-B CpG-ODN targeting of dendritic cells and intracellular delivery

We loaded nanogels with class-A or class-B CpG-ODN, and compared with the same CpG-ODNs free or admixed with empty nanogels. Encapsulation of class-A CpG-ODN (loading into Ng) strongly reduced the CpG-ODN uptake and intracellular trafficking in the cytosol; this was associated with a marked deficiency in IFN-α induction. In contrast, encapsulation of class-B CpG-ODN increased its uptake and did not influence consistently intracellular trafficking into the nucleus. The choice of CpG-ODN class as adjuvant is thus critical in terms of how it will behave with nanoparticulate vaccine delivery vehicles.263