Figure 6.

Scheme illustrating the proposed mechanism of uptake for 200 nm SiO₂–NH₂ nanoparticles in liver endothelium. The thickness of the arrows represents uptake efficiency. (a) Uptake of particles with a human plasma corona is lower than for bare particles, but the same effect is obtained with a corona made by HRG alone. (b) Particles with a human plasma corona enter cells via multiple receptors including the transferrin (Tf) receptor. However, if free Tf is added (c), it competes with the particles for the Tf receptors, and the particles are displaced to a different receptor which has higher uptake efficiency, leading to a higher uptake.