Improving endothelial cell adhesion and proliferation on titanium by sol–gel derived oxide coating

In-stent restenosis becomes increasingly prevalent as a difficult-to-treat disease. An alternative therapeutic strategy is enhancing endothelialization on metallic stent surfaces. This study attempted to modify surface chemistry and topography of commercial pure titanium (cp-Ti) by different sol–gel derived oxide coatings (TiO2, SiO2, SiO2/TiO2, and Nb2O5) to improve endothelialization. The physiochemical properties of the modified surfaces were characterized by ellipsometry, atomic force microscope, and sessile-drop method. The cell adhesion/proliferation quantity, cell adhesion morphology, and focal adhesion protein expression were evaluated with human pulmonary microvascular endothelial cell line. The thickness of oxide coatings approximates to 100 nm; significantly rougher nanoporous structure was found in the TiO2 and Nb2O5 coatings than that of cp-Ti. SiO2 coating possesses the highest surface energy (75.1 mJ/m2) and the lowest was for cp-Ti (45.7 mJ/m2). TiO2 coating showed significantly higher endothelial cell adhesion rate than others; TiO2, Nb2O5, and TiO2/SiO2 coatings exhibited higher endothelial proliferation in 3-day assays than noncoated Ti. In hemocompatible test, they also showed good hemocompatibility. These results offer the insight into that certain oxide coatings on titanium could significantly improve endothelial cell adhesion and proliferation especially in early period, which will favor reaching the endothelialization rapidly and suitable as matrix for “endothelial seeding” stent. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010