Fabrication Of Antibacterial And Osteoinductive Titanium-based Nano Hydroxyapatite Coating Via Polymer-mediated Pulse Electrochemical Deposition

In recent years,artificial bone repair material has become an ideal material for the treatment of bone tissue damage.Among them,metal implants have been widely used clinically because of their good mechanical properties.The introduction of hydroxyapatite?HA?coating on titanium surface is an effective way to improve the osteoinduction ability of implants.Titanium-based HA coating material implanted in the human body,is conducive to bacterial adhesion and reproduction,affecting the therapeutic effect.Inorganic metal antibacterial agents because of its good stability,highly efficient antibacterial often doped in the HA.However,excessive metal ions will have toxic effects on the human body.Therefore,it is necessary to introduce chelating agents into the materials in order to control the release of metal ions.In this study,hydroxyapatite,inorganic antibacterial agents and polymers were deposited on the surface of titanium via electrochemical deposition.The composite coatings with both osteoinductivity and antibacterial properties were successfully prepared.The morphology of the composite coating materials were characterized by scanning electron microscopy?SEM?.The composition of the composite coating materials were characterized by Fourier transform infrared spectrometer?FTIR?and X-ray powder diffractometer?XRD?.The thermal stability of the composite coating was analyzed using a thermogravimetric analyzer?TG?.The effects of the deposition of natural polymeric chitosan?CS?and the conductive polymer Polypyrrole?PPy?on the spherical HA-NPs,Ag-NPs,Cu-NPs and Zn-NPs.Specific research includes the following parts:?1?CS In Situ Controlled Pulsed Electrochemical Deposition to Prepare Antibacterial and Abrasion Resistant HA Coatings.The optimum deposition potentials,Ag⁺concentration and Ca²⁺concentration on the composite coatings were obtained.The composite coatings with uniform dispersion of spherical nanoparticles were obtained.HA/Ag/CS nanocomposite coatings show excellent bio-induced activity,abrasion resistance and physiological stability.The coating has excellent antibacterial properties,has no effect on the proliferation of osteoblasts and vascular endothelial cells,and can induce the differentiation of bone marrow mesenchymal stem cells into osteoblasts.?2?PPy Regulating HA Grain Refinement to Build Multifunctional Titanium HA/Ag Coatings.The effects of pyrrole?Py?,Ag⁺?Ca²⁺concentration on the morphology of the composite coatings were investigated.The formation mechanism of HA-NPs and Ag-NPs by PPy polymerization was discussed.The results show that HA/Ag/PPy composite coating has good biological activity,tribological properties,antibacterial properties,has no effect on the proliferation of vascular endothelial cells,can induce bone marrow mesenchymal stem cells to differentiate into osteoblasts.?3?PPy coordination and doping double regulation to construct multifunctional HA/Cu nano-coating.The optimal parameters of this method are Py concentration of 0.3 mmol·L^-1,Cu²⁺concentration of 0.3 mmol·L^-1 and pulse potential of 1^-1.5V.The results show that there is a good physiological stability,biological activity,antibacterial,in vitro cell culture composite coating on vascular endothelial cells and bone marrow-derived mesenchymal stem cells non-toxic.?4?PPy coordination and doping double regulation to construct multifunctional HA/ZnO nano-coating.The optimal parameters of this method are Py concentration0.3 mmol·L^-1,Zn²⁺0.03 mol·L^-1 and pulse potential 1^-2.5 V.The results show that there is a good biological activity,physiological stability and antibacterial,in vitro cell culture composite coating on vascular endothelial cells and bone marrow-derived mesenchymal stem cells non-toxic.