Stability and osteogenic potential evaluation of micro-patterned titania mesoporous-nanotube structures

Background: Although titanium dioxide nanotubes (TNTs) had great potential to promote osteogenesis, their weak bonding strength with titanium substrates greatly limited their clinical application. Purpose: The objective of this study was to maintain porosity and improve the stability of TNT coatings by preparing some micro-patterned mesoporous/nanotube (MP/TNT) structures via a photolithography-assisted anodization technology. Methods: The adhesion strength of different coatings was studied by ultrasonic cleaning machine and scratch tester. The early adhesion, spreading, proliferation and differentiation of MC3T3-E1 cells on different substrates were investigated in vitro by fluorescent staining, CCK8, alkaline phosphatase activity, mineralization and polymerase chain reaction assays, respectively. Results: Results of ultrasonic and scratch assays showed that the stability of TNTs (especially 125 nm) was significantly improved after being patterned with MP structures. In vitro cell assays further demonstrated that the insertion of MP structure into 125 nm TNT coating, which was denoted as MP125, could effectively improve the early adhesion, spreading and proliferation of surface MC3T3-E1 cells without damaging their osteogenic differentiation. Conclusion: We determined that the MP/TNT patterned samples (especially MP125) have excellent stability and osteogenesis properties, and may have better clinical application prospects.