Development of U11-functionalized gold nanoparticles for selective targeting of urokinase plasminogen activator receptor-positive breast cancer cells

The functionalization of colloidal nanoparticles with short peptides often fails in achieving satisfactory targeting efficiency and selectivity toward receptor-specific human cells. Here, we show that an optimized passivation of gold nanoparticle surface with a mixed self-assembled monolayer, including a targeting ligand, a fluorescent dye, and an intercalating short PEG derivative, led to a very stable, nontoxic, and efficient nanoconjugate for targeting urokinase plasminogen activator receptor-positive breast cancer cells. © 2014 American Chemical Society.