title: Alkalescent nanotube films on a titanium-based implant: A novel approach to enhance biocompatibility.
abstract: The interfacial pH value has a marked effect on cell viability because the pro-mineralization activity of osteoblasts increases at alkaline extracellular pH, whereas the pro-resorptive activity of osteoclasts increases under more acidic conditions. To obtain the more favorable alkaline interface, we developed a novel nanotube layer that was incorporated with magnesium oxide on a titanium implant substrate (MgO/NT/Ti) via ethylenediamine tetraacetic acid (EDTA) chelation. This facile immersion-annealing process successfully created a homogeneous magnesium oxide layer with sustained release kinetics and superior hydrophilicity according to the surface characterization and microenvironment measurement. The titania nanotubes on the substrate with an anatase phase exhibited a lower passivation current and a more positive corrosion potential compared with pure titanium, which guaranteed a reasonable corrosion resistance, even when it was wrapped with a magnesium oxide layer. In vitro cell cultures showed that MgO/NT/Ti significantly increased cell proliferation and alkaline phosphatase (ALP) activity. The resulting alkalescent microenvironment created by the MgO layer encouraged the cells to spread into polygonal shapes, accelerated the differentiation stage to osteoblast and induced a higher expression of vinculin. In summary, the incorporated alkalescent microenvironment of MgO/NT/Ti provided a viable approach to stimulate cell proliferation, adhesion, and differentiation and to improve the implant osseointegration.
authors.affiliation: Corrosion and Protection Center, Key Laboratory for Corrosion and Protection (MOE), University of Science and Technology Beijing, Beijing 100083, China.
authors.forename: Yanxian
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Corrosion and Protection Center, Key Laboratory for Corrosion and Protection (MOE), University of Science and Technology Beijing, Beijing 100083, China. Electronic address: cfdong@ustb.edu.cn.
authors.forename: Chaofang
authors.initials: C
authors.lastname: Dong
authors.affiliation: Department of Stomatology, The PLA General Hospital, Beijing 100853, China.
authors.forename: Sefei
authors.initials: S
authors.lastname: Yang
authors.affiliation: Corrosion and Protection Center, Key Laboratory for Corrosion and Protection (MOE), University of Science and Technology Beijing, Beijing 100083, China.
authors.forename: Junsheng
authors.initials: J
authors.lastname: Wu
authors.affiliation: Corrosion and Protection Center, Key Laboratory for Corrosion and Protection (MOE), University of Science and Technology Beijing, Beijing 100083, China.
authors.forename: Kui
authors.initials: K
authors.lastname: Xiao
authors.affiliation: Corrosion and Protection Center, Key Laboratory for Corrosion and Protection (MOE), University of Science and Technology Beijing, Beijing 100083, China.
authors.forename: Yunhua
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Corrosion and Protection Center, Key Laboratory for Corrosion and Protection (MOE), University of Science and Technology Beijing, Beijing 100083, China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Li
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D055664:Electrochemical Techniques; D008277:Magnesium Oxide / Q000737:chemistry; D051379:Mice; D018613:Microscopy, Confocal; D043942:Nanotubes / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D019736:Prostheses and Implants; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; C009495:titanium dioxide; D008277:Magnesium Oxide; D014025:Titanium; D000469:Alkaline Phosphatase
keywords: Alkalescent microenvironment; Biocompatibility; Magnesium oxide; Titania nanotubes; Titanium implant