Surface-Grafted Polysarcosine as a Peptoid Antifouling Polymer Brush

Abstract

Poly(N-substituted glycine) “peptoids” are a class of peptidomimetic molecules receiving significant interest as engineered biomolecules. Sarcosine (i.e. poly(N-methyl glycine)) has the simplest sidechain chemical structure of this family. In this contribution, we demonstrate that surface-grafted polysarcosine (PSAR) brushes exhibit excellent resistance to non-specific protein adsorption and cell attachment. Polysarcosine was coupled to a mussel adhesive protein inspired DOPA-Lys pentapeptide, which enabled solution grafting and control of the surface chain density of the PSAR brushes. Protein adsorption was found to decrease monotonically with increasing grafted chain densities, and protein adsorption could be completely inhibited above certain critical chain densities specific to different polysarcosine chain-lengths. The dependence of protein adsorption on chain length and density was also investigated by a molecular theory. PSAR brushes at high chain length and density were shown to resist fibroblast cell attachment over a 7 wk period, as well as resist the attachment of some clinically relevant bacteria strains. The excellent antifouling performance of PSAR may be related to the highly hydrophilic character of polysarcosine, which was evident from high-pressure liquid chromatography measurements of polysarcosine and water contact angle measurements of the PSAR brushes. Peptoids have been shown to resist proteolytic degradation and polysarcosine could be produced in large quantities by N-carboxy anhydride polymerization. In summary, surface grafted polysarcosine peptoid brushes hold great promise for antifouling applications.

Diverse Applications of Nanomedicine

“…580 The polypeptoid polysarcosine offers high water solubility, nonimmunogenicity, 581−583 and protein resistance 584 due to its special characteristics, e.g. , weak hydrogen bond acceptor with the lack of hydrogen donor capabilities.…”

Siderophores and mussel foot proteins: the role of catechol, cations, and metal coordination in surface adhesion

“…Interestingly, catechol can also be used to prevent bacterial attachment to titania surfaces. Several materials utilize catechol as an anchor for antifouling self-assembled monolayers (SAMs) on titania as well as other metal oxide [66,67].…”

Peptoids for biomaterials science

“…Intriguingly, polymer brushes composed of sarcosine, the peptoid with the simplest sidechain (a single methylene: Figure 4), exhibited antifouling performance that is similarly excellent as peptoids with methoxyethyl sidechains that resemble the repeating unit of PEG. 35,40,42 In both cases, protein adsorption could essentially be prevented at chain lengths of just 20 repeating units, and long term fibroblast attachment could also be prevented (Figure 4). 35,40 The resistance against bacteria attachment ranged from 75% to 99% (1 d), depending on the combination of the sidechain and the bacteria strain being tested.…”

“…35,[40][41][42][43] Several peptoid sidechains and chain lengths have been investigated. Intriguingly, polymer brushes composed of sarcosine, the peptoid with the simplest sidechain (a single methylene: Figure 4), exhibited antifouling performance that is similarly excellent as peptoids with methoxyethyl sidechains that resemble the repeating unit of PEG.…”