Titanium surface modification by acidic oxidation treatment activates the Wnt signaling pathway in bone marrow mesenchymal stem cells

Wang Wei; Du Yuan-hong

doi:10.3969/j.issn.2095-4344.0404

Abstract：BACKGROUND: Preliminary findings have shown that titanium dioxide nanotube array prepared on the titanium surface by an anodizing method can significantly affect the osteoblast differentiation. OBJECTIVE: To observe the effect of titanium surface modification by acidic oxidation treatment on the Wnt signaling pathway in bone marrow mesenchymal stem cells. METHODS: The micro/nano-structure composed of nanotubes was prepared by acidic oxidation method. The oxidizing voltage was set to 5 V and 20 V. The polished pure titanium was used as control. Primary cultured Sprague-Dawley rat bone marrow mesenchymal stem cells were seeded onto the titanium surface of the three groups. After 3 and 7 days of incubation, real-time quantitative PCR was used to detect the genes levels of canonical Wnt and non-canonical Wnt signaling pathway and western blot method was used to detect β-catenin expression level in the nuclei, respectively. RESULTS AND CONCLUSION: (1) Canonical Wnt signaling expression: Wnt1 and Wnt3a expression on the micro/nano-structure surfaces significantly increased compared to the control surface (P < 0.05). (2) Non-canonical Wnt signaling expression: compared with the control surface, Wnt4 expression decreased on the two kinds of micro/nano structure surfaces (P < 0.05); Wnt7a decreased on the small-diameter nanotube (R5) surface (P < 0.05), increased on the big-diameter nanotube surface (R20) (P < 0.05); Wnt11 elevated on both two micro/nano structure surfaces (P < 0.05). Wnt5a expression level had no obvious change in the three groups. (3) β-catenin expression level in the nuclei significantly increased after titanium surface modification by different acidic oxidation treatments compared to the control surface. These results show that the micro/nano-structure titanium surface activates the canonical Wnt signaling pathway in the bone marrow mesenchymal stem cells.