Preparation Of Bioactive Films On Medical Titanium Surface And Study On Its Biological Properties

Titanium and titanium alloys are a kind of biomedical metallic material with stable physicochemical properties,excellent mechanical properties and biocompatibility Although they have been widely used as medical implants in the field of hard tissue repair and replacement,there are still some problems at present.On the one hand,titanium and titanium alloys are bioinert which can not form a active bond between implant and bone tissue,that is not conducive to the long-term stability of the implant.On the other hand,the titanium implant surface is prone to infection during the operation,which leads to a failure of implantation.Therefore,the development of surface modifications to construct more ideal structure and function on titanium implant materials is a major focus of current research.In this paper,the surface of titanium materials were modified from the two aspects of biological activity and surface antibacterial property.Different coatings were constructed on the surface of titanium through electrochemical etching,electrochemical deposition and other technologies,so as to improve the biological and antibacterial properties of titanium materials.The main progresses are listed as follows:1.Electrochemical deposition was carried out for the preparation of composite films of octacalcium phosphate/?-polylysine(OCP/?-PL)on the surface of titanium with different concentrations of ?-PL for the frist time.The results of simulated body fluid(SBF)immersion test show that the OCP/?-PL composites have better ability to induce bone-like apatite formation than the OCP samples.The experiments of protein adsorption and in vitro cell culture express that the OCP/?-PL composite membranes have the highest adsorption capacity and promoted cell proliferation and differentiation when the concentration of ?-PL is 10 mg/mL2.The antibacterial properties of the OCP/?-PL composite films with different concentration and OCP films exhibit that the OCP/?-PL composite films are able to inhibit the adhesion of Escherichia coli and Staphylococcus aureus on the surface of the materials and kill the bacteria as well.And with the increase of the concentration of s-PL,the antibacterial activity of OCP/?-PL films is obviously increased.3.A microhole-ordered/nano-hydroxyapatite hierarchical structure was obtained by two-step surface process.The electrochemical etching was conducted to construct microhole-ordered on the surface of titanium,and then a layer of nano-hydroxyapatite was electrochemically deposited on the titanium surface with microhole-ordered structure.The contact Angle tests and protein adsorption experiments were carried out on pure titanium,microhole-ordered and microhole-ordered/nano-hydroxyapatite hierarchical structure.The results indicate that the hydrophilicity of microhole-ordered/nano-hydroxyapatite hierarchical structure is enhanced,and it shows highest protein adsorption capacity.In vitro cell culture experiments show that microhole-ordered/nano-hydroxyapatite hierarchical structure has good cell adhesion and proliferation,and possesses optimal cell differentiation and extracellular matrix mineralization properties.