The generation of surfaces and interfaces that are able to withstand protein adsorption is a major challenge in the design of blood-contacting materials for both medical implants and bioaffinity sensors. Poly(ethylene glycol)-derived materials are generally considered to be particularly effective candidates for the fabrication of protein-resistant materials. Most metallic biomaterials are covered by a protective, stable oxide film; converting such oxide surfaces, which are known to strongly interact with proteins, into noninteractive surfaces requires a specific design of the surface/interface architecture. A class of copolymers based on poly(l-lysine)-g-poly(ethylene glycol) (PLL-g-PEG) was found to spontaneously adsorb from aqueous solutions onto several metal oxide surfaces, such as TiO2, Si0.4Ti0.6O2, and Nb2O5, as measured by the in situ optical waveguide lightmode spectroscopy technique and by ex situ X-ray photoelectron spectroscopy. The resulting adsorbed layers are highly effective in reducing th...