Study On Construction Of Superhydrophobicity And Ag Nanoparticles On Orthopedics Implants And Evaluation Of Anti-bacteria Properties

Though implants promotes the development of orthopeadics,it increases therisk of infection. The complication of infection causing by implants is a disasterwhich leads to much money loss and challenges the decision of orthopeadist ontreatment.When implants are put into body, the body fluid will wrap up them in aminute and FNs also adhere on the surface of implants. FN is primary biologicalreason of bacterial planting and adhesion on the surface, and bacterial adhesion isfirst reason of implants infection, so superficial bacteriostatic or antibacterialmodification of implants becomes a new treatment or prevention for that theinfection occurs at the interface between the implants and surrounding tissues andbegins from the adhesion of bacterial. Theoretically, the bacteriostatic orantibacterial microenvironment forming after the surface modification reduces theadhesion of bacterial, improving autoimmunity and the antibiotic ability inbacterial–killing. In additional, by using electrodeposition, we loaded Ag coatingon the surface of implants and it was made implants anti-bacterial by Ag.Objective:In order to reduce the infection probability of implants, the problem ofbacterial planting and adhesion on the surface, the first step of infection, is thefirst one to solve. Analyzing the action mechanism of bacterial adhesion todifferent hydrophilic and hydrophobic surfaces of implants, a design proposal israised here to decrease the surface hydrophilicity and turn it intosuper-hydrophobicity, and the result of bacteriostasis was verified also.Meanwhile, a carrier-section carrying effect antibiotic was made on the titaniumsurface and the result was observed. Material and methods:1. Using the electrochemistry anodic oxidation method to make amembrane of TiO₂nanotube arrays at the titanium surface.2. Using a self-assembly method，at the basis of the membrane of TiO₂nanotube arrays, to make a superhydrophobic surface by modifying thesurface with a hypo-energy materials.3. Analying the superhydrophobicity of titanium surface after self-assemblythrough a CA analysator4. Comparing the effects of different surfaces on FN and bacterial adhesionin vitro, observing the anti-adhesion efficacy of superhydrophobicity oftitanium surface.5. By two-step electrochemical method, we constructed the OCP/Agcomposite coatings on TiO₂NTs.6. Observing the antibiosis efficacy of the membrane of OCP/Ag/TiO₂through vivo and vitro antibiosis experiments.Results:Surface shape: by controlling the parameters of reaction voltage and reactiontime, a regular and uniformity tubiform can be made on the Ti-surface andforming a brush of nanotube array in a solution with fluorine.The bacteriostasis result of hyperhydrophobic surface: When modificationingthe TiO₂nanotube array with hypo-energy surface material PETS, the CA can be156°±1.0°.As certificated by vitro experiment of bacteriostasis, compare tohydrophilic and common hydrophobic surfaces, hyperhydrophobic surface canreduce FN and bacterial adhesion effectively.The antibiosis experiment of OCP/Ag/TiO₂: As verified by vitro experiment,OCP/Ag/TiO₂can decrease bacterial adhesion and can kill almost attachedbacterial. In animal experiment, OCP/Ag/TiO₂can improve the clinic symptomsof bone infection and osteomyelitis. The result of pathology is that the degree ofbone marrow infection, cortical bone destroy and periosteal reaction on the trial side is higher than the control side.Conclusion:1. A membrane of TiO₂nanotube array was made at the titanium surfacewith galvanochemistry anodic oxidation methods.2. On the surface of the membrane of TiO₂nanotube array,super-hydrophobic surface was formed, decreasing the ability ofbacterial adhesion and planting obviously.3. The evaluation of biological properties was done by in vitro cell culture,antibacterial test and in vivo animal test. The results proved that theOCP/Ag/TiO₂composite coating not only owned biocompatibility, butalso anti-bacterial property to S. aureus.