Figure 4. Nanoparticle transport route changes with nanoparticle sizes.

Nanoparticles with larger sizes over 100 nm are captured by dendritic cells from outside of lymphatic epithelia, in comparison, soluble protein antigen and smaller nanoparticles less than 10 nm are able to penetrate through lymphatic epithelia. Once antigens transported into lymph nodes via lymphatic vessels, they are presented to B cells and T cells by follicle dendritic cells. The larger nanoparticles are much more efficiently taken up by dendritic cells than smaller nanoparticles and potentially induce stronger and long-term specific immunity.