Surface-Initiated Poly(oligo(2-alkyl-2-oxazoline)methacrylate) Brushes

Polymer brushes are particularly performant antifouling coatings, owing to their high grafting density that prevents unwanted biomacromolecules to diffuse through the coating and adhere to the underlying substrate. In addition to this structural feature, polymer brushes require a relatively high level of hydrophilicity and a globally neutral structure to display ultrahigh protein resistance. Poly(2-alkyl-2-oxaolines) are attractive building blocks for such coatings as they can display relatively high hydrophilicity, owing to their amide repeat units, but can also be side-chain and end-chain functionalized relatively readily. However, poly(2-alkyl-2-oxazolines) have not yet been introduced through a radical-mediated grafting from polymer brush structure that would confer the high level of grafting density that is the hallmark of highly protein resistant brushes. Here, we present the formation of a series of poly(oligo(2-alkyl-2-oxazoline)methacrylate) brushes generated via a grafting from approach, via atom transfer radical polymerization. We characterize the chemical structure of the resulting coatings via ellipsometry, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. We show that allyl end groups can be introduced as a side chain of these brushes to allow functionalization via thiol-ene chemistry. We demonstrate the excellent protein resistance of these coatings in single protein solutions as well as serum solutions at concentration typically used for cell culture. Finally, we demonstrate the feasibility of using these brushes for the micropatterning of cells and the generation of cell-based assays.