Zwitterionic Polymer Coatings for Stable and Stealthy Nanocrystals in Bioimaging and Micromanipulation

Inorganic nanocrystals such as gold, iron oxide and semiconductor nanocrystals have unique optical or magnetic properties that make them very promising for cancer detection, imaging and therapeutic applications. The surface ligands of these nanoparticles play a critical role in their application and control the nanoparticle interaction with biomolecules and cells. I will present the development of zwitterionic copolymer ligands containing a multidentate anchoring block, adaptable to the type of nanoparticle, and that provide a stable binding to the surface of different inorganic nanocrystals, enabling prolonged biological applications. The nature of the zwitterion group has a strong influence on antifouling properties, ranging from specific interactions with some biomolecules to a complete suppression of interactions with serum biomolecules, cytosolic components and macrophage cells. This enables various applications including intracellular targeting of fluorescent quantum dots, in vivo tracking of individual circulating cells, or micromanipulation in the nucleus of living cells using magnetic nanoparticles.