**2. Nanoparticle-Cell Dynamics**

In general, NPs enter the cells through di fferent internalization mechanisms (Figure 1), accumulate in targeted organs, and are later eliminated.

**Figure 1.** Schematic representation of different ways to enter nanoparticles (NPs) in the human body and inside cells.

Their small size allows them to enter the human body by inhalation, ingestion, or through the skin. Once in the extracellular fluid, they are conjugated with biomolecules presented in the media, which allows them to internalize in the cells.
