Effects of Titanium Micro-Nanopermeable Structures on Osteogenic Differentiation

To evaluate the effects of different Ti surface micro-nanopermeable structures on osteoblast proliferation and differentiation and explore related mechanisms, hybrid technology of sandblast, acid etching, and hydrothermal (HT) was used to form the micro-nanopermeable surface of Ti. Scanning electron microscopy (SEM), surface profiler, and contact angle meter were utilized to assess the surface morphology, roughness, and hydrophilicity. MTT, SEM, alkaline phosphatase (ALP) activity assay, and real-time PCR were performed to investigate proliferation, adhesion and spreading, and differentiation of MC3T3-E1 cells grown on polished Ti (control), sandblast + acid etching- (SLA-) treated Ti, and SLA + HT-treated Ti. MAPK signal pathway activity was evaluated by Western blotting. The results showed that SLA + HT could result in not only formation of microscale groove containing submicroscale and nanoscale porous structures in Ti samples but also rough and hydrophilic surface. SLA + HT treatment has the best effects on cell adhesion and spreading. Significantly increased levels of ALP activity and osteogenic genes including Alp, Ocn, Opn, Runx2, and Bsp, as well as p38 but not ERK phosphorylation, were found in the SLA + HT group. In conclusion, sandblast, acid etching, and hydrothermal treatment on Ti regulates osteoblast differentiation, while activation of the MAPK p38 signaling pathway served as the mechanism