  For applications in nanomedicine, particles need to be functionalized to
prevent protein corona formation and or aggregation. Most advanced strategies
take advantage of functional polymers and assembly techniques. Nowadays there
is an urgent need for coatings that are tailored according to a broad range of
surfaces and that can be produced on a large scale. Herein, we synthesize mono-
and multi-phosphonic acid based poly(ethylene glycol) (PEG) polymers with the
objective of producing efficient coats for metal oxide nanoparticles. Cerium,
iron, titanium and aluminum oxide nanoparticles of different morphologies
(spheres, platelets, nanoclusters) and sizes ranging from 7 to 40 nm are
studied in physiological and in protein rich cell culture media. It is found
that the particles coated with mono-functionalized polymers exhibit a mitigated
stability over time, whereas the multi-functionalized copolymers provide
resilient coatings and long-term stability (months). With the latter, PEG
densities in the range 0.2 - 0.5 nm-2 and layer thickness about 10 nm provide
excellent performances. The study suggests that the proposed coating allows
controlling nanomaterial interfacial properties in biological environments.
