Figure 5.

Cobalt nanomaterials help to enhance immunization efficacy. Co3O4NPs can penetrate human skin and introduce considerable immunostimulatory when pulsed with macrophages. Macrophages have powerful phagocytosis, digestion, and killing functions, can intake pathogens such as virtual particles, form phagosomes, and fuse with lysosomes forming phagolysosomes, through oxygen-dependent and oxygen-independent systems, under the participation of a variety of enzymes, and kill and digest pathogens. Additionally, macrophages are an important class of dedicated antigen-presenting cells that can uptake, process antigens, and present antigen peptide-MHC-II molecular complexes to CD4+ T cells.