Overcoming Hepatic Biotransformation Barrier of Gold Nanoparticles via Au-Se Bond for Enhanced Active Targeting.

As a key metabolic function of the liver, the hepatic biotransformation process can alter the predesigned surface chemistry of nanoparticles , leading to hampered functionality and targeting ability. However, strategies to modulate the hepatic biotransformation of nanoparticles have been rarely explored. Herein, using indocyanine green (ICG)-conjugated gold nanoparticles that target liver hepatocytes as a model, we showed that merely changing the metal-ligand bond from gold-sulfur (Au-S) to gold-selenium (Au-Se) completely reshaped the hepatic biotransformation profiles of the nanoparticle as well as its targeting and transport behaviors . Compared with those of Au-S bond, Au-Se bond markedly slowed down nanoparticle biotransformation in liver sinusoids, enhanced ICG-mediated nanoparticle targeting to hepatocytes by 15-fold, and also altered nanoparticle intrahepatic transport, distribution, and clearance pathways. Moreover, we demonstrated that Au-Se bond could improve the active targeting of gold nanoparticles to hepatic tumors by reducing liver biotransformation-induced dissociation of targeting ligands. These discoveries not only deepen our understanding of nanoparticle biotransformation in the liver but also offer a strategy to overcome the biochemical barrier of hepatic biotransformation, providing guidance for the design and engineering of related nanomedicines by tuning their biotransformation profiles.