Revealing the impact of poly(ethylene oxide) blocks on enzyme activable coatings from peptide-polymer conjugates

P. Wilke and H. G. Börner,

Humboldt Universität zu Berlin; Department of Chemistry; Laboratory for Organic Synthesis of Functional Systems; Brook-Taylor-Str. 2, 12489 Berlin (Germany).

Abstract: Peptide-polymer conjugates composed of a poly(ethylene oxide) (PEO) block and a precursor segment from mussel foot protein-1 (mefp-1) are enzymatically oxidized by tyrosinase. A functional transition from weak/reversible binders to strong/irreversible adsorption onto aluminum oxide surfaces is observed. To elucidate effects of PEO-block length on the enzyme activable formation of antifouling coatings on aluminum oxide surfaces, a set of mefp-1-block-PEO bioconjugates with PEO-block lengths of 850, 3200 and 5200 g/mol is synthesized and investigated. The variation of PEO-block length systematically affects the activation kinetics of the bioconjugates by tyrosinase, the adhesion behavior of the activated bioconjugates, the stability of the resulting aluminum oxide coatings and the antifouling properties of coated aluminum oxide surfaces. Mefp-1-block-PEO3200 exhibits the best compromise as enzyme activation and adhesive properties showed excellent behavior. Stable coatings on aluminum oxide are formed in the activated state, which reduce albumin protein interactions in a practically quantitative manner. The coating appears to be sufficiently dense and stable to reach similar antifouling properties as covalently “PEGylated” aluminum substrates.