OICC Press Journal of Nanostructure in Chemistry 2193-8865 16 5 2026 10 31 Surface Modification of Cardiovascular Stents with TiO₂ Nanotube Arrays: In Vitro Investigation of Interfacial Properties and Endothelialization 10.57647/jnsc.2026.1605.22 EN Changcun Fang Postdoctoral Scientific Research Workstation, Engineering Research Center for Sugar and Sugar Complex, National-Local Joint Engineering Laboratory of Polysaccharide Drugs, Key Laboratory of Carbohydrate and Glycoconjugate Drugs, Shandong Academy of Pharmaceutical Science, Jinan, Shandong 250101, China Lei Chen Postdoctoral Scientific Research Workstation, Engineering Research Center for Sugar and Sugar Complex, National-Local Joint Engineering Laboratory of Polysaccharide Drugs, Key Laboratory of Carbohydrate and Glycoconjugate Drugs, Shandong Academy of Pharmaceutical Science, Jinan, Shandong 250101, China Fei Liu Postdoctoral Scientific Research Workstation, Engineering Research Center for Sugar and Sugar Complex, National-Local Joint Engineering Laboratory of Polysaccharide Drugs, Key Laboratory of Carbohydrate and Glycoconjugate Drugs, Shandong Academy of Pharmaceutical Science, Jinan, Shandong 250101, China Journal Article 2026 10 31 The long-term performance of cardiovascular stents is compromised by pathological events such as restenosis and late thrombotic failure, which together motivate surface-engineering strategies that can promote vascular healing while regulating the earliest interfacial events. In this study, titanium dioxide (TiO₂) nanotube (TNT) arrays were fabricated on Ti-6Al-4V alloy by electrochemical anodization and subsequently annealed at 450 °C and 600 °C to tune their crystalline phase. FESEM, TEM, XRD, Raman spectroscopy, XPS, AFM, and water-contact-angle analysis were used to characterize the resulting morphological, structural, and chemical changes. The data show that the interfacial behavior of the nanotube layers is strongly phase dependent. Among the tested surfaces, the 450 °C-annealed TNTs, characterized by an anatase-rich structure and a superhydrophilic response, displayed the most favorable albumin-over-fibrinogen adsorption pattern and supported the strongest HUVEC attachment and proliferation. These results indicate that moderate annealing yields an interfacial environment in which ordered nanotopography, anatase-dominated crystallinity, and hydration-favorable surface chemistry act together to support endothelialization. Compared with both the amorphous TNT-As layer and the more strongly transformed TNT-600 surface, TNT-450 appears to occupy a more favorable physicochemical window in which surface hydration, adsorption selectivity, and cell-facing interactions are balanced most effectively. The mixed-phase TNT-600 surface still performed better than the bare alloy, but its partially rutile-containing interface showed a weaker combination of wettability, protein selectivity, and endothelial response than TNT-450, indicating that excessive thermal transformation is not advantageous under the present conditions. Overall, phase-engineered TiO₂ nanotube arrays represent a promising drug-free strategy for improving stent-surface biointegration. Direct dynamic blood-contact validation under flow and stent-form conditions remains an important next step.