Construction And Properties Of Multifunctional Drug Loaded Composite Coating On Titanium Substrate Controlled By Polypyrrole

Patients with osteoporosis are often from the elderly and menopausal women.The reduced bone mineral density in osteoporosis patients can lead to frequent fractures and a surge in demand for artificial implants.Biomedical titanium(Ti)has good mechanical and chemical stability,high corrosion resistance and biocompatibility is widely used in clinical practice,but titanium metal has no antibacterial properties,which can easily cause bacterial adhesion and postoperative infection.Meanwhile,titanium is a biologically inert material,and its inability to form good osseointegration with surrounding tissues leads to loosening of titanium implants,which limits the clinical application of titanium implants.Therefore,constructing a multifunctional coating with antibacterial and osseointegration-promoting properties on the titanium surface is an effective strategy to solve the above problems.The specific research of this thesis is as follows:(1)Construction of highly dense HA/MgO nanocomposite coatings on titanium surfaces.Uniformly distributed HA/CS/Mg(OH)₂ nanocoatings were prepared by pulsed electrochemical deposition(PED)driven CS,which were sintered at high temperature to obtain HA/MgO composite coatings,which were uniformly distributed and dense,At the same time the nanoparticles are uniformly dispersed.The metal ions in the coating are released slowly without sudden release,and the coating promotes the deposition of calcium and phosphorus salts.Osteoblasts and vascular endothelial cells grow well on the surface of the coating.(2)Construction of Lignin/Ag-NPs/PLL nanocomposite coating on titanium surface.The self-assembly method was used to utilize the reducing and adhesive properties of the mussel-like material Lignin to uniformly distribute the antimicrobial agent Ag-NPs and osteoinductant PLL on the substrate surface to obtain the Lignin/Ag-NPs/PLL composite coating,which is photo-responsive and generates a large amount of ROS and heat under 808 nm NIR laser irradiation,and the final composite material achieves fast and strong antimicrobial The coating has a slow release of metal ions,no sudden release,and rapid sterilization in a short period of time,with good growth of osteoblasts and vascular endothelial cells on the surface of the coating.(3)Construction of TA@Cu(II)/PLL nanocomposite coating on titanium surface.The TA@Cu(II)/PLL composite coating was obtained by self-assembly method using the adhesion of tannic acid and metal ion chelating ability,based on the inherent photoresponsiveness of TA-Cu(II),which generates ROS by external light stimulation to achieve rapid sterilization,and in order to remove the excess ROS generated by photothermal and avoid tissue damage,a natural antioxidant TA was added to the coating,and TA and Cu²⁺to form a metal phenolic network with strong photothermal conversion efficiency,rapid bactericidal and antioxidant capabilities,and excellent osteogenic activity,angiogenic properties and good bioactivity.