The Effect Of Micro-nano Permeable Surface Morphology Of Pure Titanic Implant On Osteointegration

ObjectiveOur study focuses on the biological effect of micro-nano permeable structure of titanium surface on bone osteointegration.We aim to improve the fabrication method of micro-nano permeable structure and evaluate physicochemical property,additionally explore the functions and mechanisms of micro-nano permeable surface structure to osteoblast differentiation.Methods1.Scanning electron microscope,energy dispersive spectrometer(EDS),contact angle meter and MTT were performed to evaluate the effect of different methods of sandblast acid etching and hydrothermal on surface morphology and biological behavior2.Hybrid technology of sandblast,acid-etching and hydrothermal were used to form the micro-nanopermeable surface of titanium.Meanwhile SEM,EDS,surface profiler and contact angle meter were utilized to assess the surface morphology,elementary composition,pore diameter distribution,roughness and hydrophilicity.3.MTT,SEM,alkaline phosphatase(ALP)activity,real-time PCR and western-blot were performed to investigate the function of different surface morphologieson osteoblast proliferation,attachment,spreading,differentiation and MAPK signal pathway.Results1.Optimization of surface modification:a.Sandblast:The regular,hierarchical structuresurface with better hydrophilicity wasobservedwith400?m Si O₂particle sandblast.b.Acid-etching:The more regular surface without noxious residues was obtained with dual acid etching of HCl and H₂SO₄.c.Hydrothermal process:The micro-nanopermeable surface with a proper strength wasformed through hydrothermal process with 4 mol/L Na OH for 4 h.2.Micro-nano permeable surface had discrete pore diameter distribution,super hydrophilicity,proper roughness and themost obvioushierarchical structure.3.Micro-nano permeable surface could significantly promote osteoblast attachment,spreading,ALP activity and osteogenetic genes expression.This surface activated p38/MAPK signal pathway to induce osteoblast differentiation.Conclusions1.The micro-nano permeable surface processed by hybrid technology of sandblast,acid etching and hydrothermal process has advantages of obvious hierarchical structure,super hydrophilicity,appropriate roughness and permeability.2.The micro-nano permeable surface structure not only maintains proliferation ability of osteoblasts,but also enhances the attachment,spreading and differentiation abilities through activating p38/MAPK signal pathway.