Fig. 2

Schematic of the hepatic and intracellular trafficking of NMs. After entering the liver via the portal vein, NMs traversing the hepatic sinusoid are primarily taken up by the MPS, mainly by KCs. NMs escaping from the MPS are taken up by LSECs and may pass through LSEC fenestrae before being taken up by hepatocytes and HSCs. For intracellular trafficking, NMs are typically entrapped in endosomes and degraded in lysosomes. Metal NMs and their oxides may be degraded to metal ions and bound to acid radicals, forming metal salt products. Nonmetallic NMs and their oxides may be degraded to acids. NM degradation products released from lysosomes or NMs that escape from endosomes also target intracellular organelles. Finally, degraded NM products are excreted from cells