A facile approach to surface modification on versatile substrates for biological applications

Abstract

A poly(ethylene glycol) (PEG) derivative, poly(ethoxyethyl glycidyl ether-co-allyl glycidyl ether)-g-catechol (PEAC), has been synthesized. With vinyl side groups, this polymer can readily undergo further thiol–ene photochemical reactions. Due to the existence of the pendant catechol functional groups, PEAC can be attached onto the surface of various substrates, including hydrophilic (e.g. glass), metallic (e.g. titanium) and hydrophobic (e.g. polytetrafluoroethylene) substrates. Various thiols can be subsequently immobilized onto the PEAC-modified surfaces through the thiol–ene reaction. The surface PEGylation and further thiol immobilization have been verified by static water contact angle, ellipsometry and XPS measurements. The results of 3T3 fibroblast cell adhesion assays show that the PEAC-modified substrates have good biological anti-fouling ability. Thus this material would be used on medical implants and diagnostic devices, as well as other applications where the reduction of surface fouling is desired. More interestingly, the PEAC-modified surface is cell-repelling but exhibits excellent cell adhesion ability after further attachment of 3-mercaptopropionic acid. It would thus allow for designing and adjusting the cell adhesion ability of the substrates. This versatile, substrate-independent approach should be of significance for the development of new materials in the field of cell culture and tissue engineering.