Surface-Grafted Polysarcosine as a Peptoid Antifouling Polymer Brush

摘要

Poly(N-substituted glycine) “peptoids” are a class ofnpeptidomimetic molecules receiving significant interest as engineerednbiomolecules. Sarcosine (i.e., poly(N-methyl glycine)) has the simplest sidenchain chemical structure of this family. In this Article, we demonstrate thatnsurface-grafted polysarcosine (PSAR) brushes exhibit excellent resistancento nonspecific protein adsorption and cell attachment. Polysarcosine wasncoupled to a mussel adhesive protein-inspired DOPA-Lys pentapeptide,nwhich enabled solution grafting and control of the surface chain density ofnthe PSAR brushes. Protein adsorption was found to decrease monotonicallynwith increasing grafted chain densities, and protein adsorption could be completely inhibited above certain critical chainndensities specific to different polysarcosine chain lengths. The dependence of protein adsorption on chain length and density wasnalso investigated by a molecular theory. PSAR brushes at high chain length and density were shown to resist fibroblast cellnattachment over a 7 week period, as well as resist the attachment of some clinically relevant bacterial strains. The excellentnantifouling performance of PSAR may be related to the highly hydrophilic character of polysarcosine, which was evident fromnhigh-pressure liquid chromatography measurements of polysarcosine and water contact angle measurements of the PSARnbrushes. Peptoids have been shown to resist proteolytic degradation, and polysarcosine could be produced in large quantities bynN-carboxy anhydride polymerization. In summary, surface-grafted polysarcosine peptoid brushes hold great promise fornantifouling applications.