Regulation Of The Surface Microstructure Of Polyetheretherketone And Loading Of Bone Morphogenetic Protein-2

With the development of medical technology,the traditional metal materials such as titanium and stainless steels are widely used in the field of hard tissue engineering.However,the potential ion release of metal materials and differences in the elastic modulus of the host bone may lead to the failure of the implant.As an organic polymer,polyetheretherketone(PEEK)has the advantage that its elastic modulus is between the cancellous bone and the bone compact.Additionally,PEEK is not easily degraded and release toxic substances in the physiological environment as a result of its good corrosion resistance and chemical stability.PEEK has excellent mechanical properties and biocompatibility,and has great potential in biomedical implant applications.However,the inert surface property of PEEK makes it exhibit poor osteogenic activity and inferior osseointegration with bone tissues after implantation,which limits its application as biomaterials.In this paper,surface chemical modification was employed to modify PEEK surface to improve the bioactivity of materials,and the surface properties and their influence on biological performances were evaluated and discussed.Surface chemical modification was used to construct structures on PEEK surface,and structures were further regulated in order to improve the biological activity of PEEK materials.Meanwhile,the cell compatibility and the ability of osteogenic differentiation of rat bone marrow mesenchymal stem cells induced were evaluated,and the effect of surface properties on their biological properties was preliminarily discussed.The main results of this work are described as follows:1.sulfonation of PEEK by concentrated sulfuric acid,and a three-dimensional pore structure containing S element was constructed on PEEK surface.Then tbone morphogenetic protein-2(BMP-2)was loaded in the surface.Due to the double effect of structure and composition,Surface hydrophilicity of PEEK material was improved obviously,and the proliferation activity,alkaline phosphatase(ALP)activity and collagen differentiation ability of rat bone marrow mesenchymal stem cells(rBMSCs)increased significantly,indicating that the modified materials promoted the early differentiation.2.sulfonation of PEEK was carried out with concentrated sulfuric acid.Then the structure was reregulated by sodium borohydride(NaBH4).A Micro nano structure was successfully constructed on the PEEK surface and hydroxyl functional groups were obtained.The surface hydrophile of the modified material was slightly lower,however it showed good bioactivity.Cell adhesion and spreading of rBMSCs were improved obviously,meantime,the ALP activity of rBMSCs was also up-regulated,indicating the modified surface is favorable for early osteogenic differentiation.In this paper,the surface structure and composition of PEEK were regulated by surface chemical modification,and the biological activity was obviously improved.The influence of the surface properties on the biological properties was also discussed,which provided a scientific basis for the implant application.