Fig. 3

PC formation on the surface of Exos inside in vivo conditions. Both hard and soft PC layers are generated around Exos as a result of non-specific interactions, and ligand-receptor affinity. The binding of different serum proteins on the exosomal surface can affect the hydrodynamic size, biodistribution, colloidal stability, and ligand-receptor interaction between Exos and acceptor cells. The formation of PC around Exos can also lead to the scavenging of these nanoparticles via the reticuloendothelial system. Meanwhile, the circulation time and delivery capacity of Exos are diminished as well. The binding of specific factors such as complement subsets increases the uptake of Exo by immune cells