Figure 4.

Nanoparticle properties such as size, shape, and charge influence macrophage internalization. Property parameters that increase macrophage uptake are indicated with the darker bar. Particles between 30 nm and 3 μm in size induce optimal particle uptake. Spheroid particles demonstrate higher uptake compared to rod-like or disc-like shaped particles. Both highly anionic or highly cationic particles undergo high uptake. Nanoparticles are primarily cleared by the lungs, liver, kidney, and spleen. Understanding the effect of these parameters on macrophage uptake can improve particle design to target desired cell populations and reduce clearance.