Complementary Supramolecular Functionalization Enhances Antifouling Surfaces: A Ureidopyrimidinone-Functionalized Phosphorylcholine Polymer

Fibrosis of implants remains a significant challengein the useof biomedical devices and tissue engineering materials. Antifoulingcoatings, including synthetic zwitterionic coatings, have been developedto prevent fouling and cell adhesion to several implantable biomaterials.While many of these coatings need covalent attachment, a conceptuallysimpler approach is to use a spontaneous self-assembly event to anchorthe coating to a surface. This could simplify material processingthrough highly specific molecular recognition. Herein, we investigatethe ability to utilize directional supramolecular interactions toanchor an antifouling coating to a polymer surface containing a complementarysupramolecular unit. A library of controlled copolymerization of ureidopyrimidinonemethacrylate (UPyMA) and 2-methacryloyloxyethyl phosphorylcholine(MPC) was prepared and their UPy composition was assessed. The MPC-UPycopolymers were characterized by H-1 NMR, Fourier transforminfrared (FTIR), and gel permeation chromatography (GPC) and foundto exhibit similar mol % of UPy as compared to feed ratios and lowdispersities. The copolymers were then coated on an UPy elastomerand the surfaces were assessed for hydrophilicity, protein absorption,and cell adhesion. By challenging the coatings, we found that theantifouling properties of the MPC-UPy copolymers with more UPy mol% lasted longer than the MPC homopolymer or low UPy mol % copolymers.As a result, the bioantifouling nature could be tuned to exhibit spatio-temporalcontrol, namely, the longevity of a coating increased with UPy composition.In addition, these coatings showed nontoxicity and biocompatibility,indicating their potential use in biomaterials as antifouling coatings.Surface modification employing supramolecular interactions providedan approach that merges the simplicity and scalability of nonspecificcoating methodology with the specific anchoring capacity found whenusing conventional covalent grafting with longevity that could beengineered by the supramolecular composition itself.