A modular monolayer coating enables cell targeting by luminescent yttria nanoparticles

Luminescent Eu(3+)-doped Y(2)O(3) nanoparticles are functionalized for cell targeting using a modular, multisegmented approach based on a phosphonate monolayer platform. The first segment provides hydrolytic stability for the particle-organic interface; the second enables aqueous suspendability; the third is used to bond cell attachment molecules. In vitro imaging experiments showed enhanced cell attachment of activated nanoparticles conjugated with cell attachment peptides compared to control nanoparticles. Peptide-derivatized nanoparticles are not displaced from the cells by their soluble peptide analogue, which suggests strong, polyvalent cell-particle interactions.