Effect of polydimethylsiloxane surfaces silanized with different nitrogen-containing groups on the adhesion progress of epithelial cells

There have been few studies on the effect of the grafting of nitrogen-containing functional groups on polydimethylsiloxane (PDMS) surfaces and, in particular, the CN bond, on cell adhesion to the surfaces. In this study, two different silanes, one containing an amine group [(3-aminopropyl)trimethoxysilane; APTMS] and the other a nitrile group [(3-cyanopropyl)triethoxysilane; CPTES], were adopted to modify PDMS following oxygen plasma treatment. The effects of surface modification on the density of HeLa and MDCK cells were evaluated, in addition to the measurement of the contact angle with the surface and the chemical composition. The results indicated that the CPTES modification allowed the PDMS surface to have better hydrophilicity than the APTMS modification. Nitrogen-containing functionalities were more beneficial for cell spreading, in comparison with the pristine and oxygen plasma-treated PDMS. The present method of APTMS and CPTES grafting provides a simple and efficient method for promoting cell adhesion on PDMS.