Research On Bone Repair Materials Based On Polyimide And Polyetheretherketone

As special engineering plastics,polyimide（PI）and polyetheretherketone（PEEK）are widely used in the medical field due to their excellent physical and chemical properties.In this thesis,we focus on research and development of materials for bone tissue engineering.We selected polyether ether ketone and polyimide as base materials respectively,modified them,and studied a series of excellent properties of the above two materials as materials for bone tissue engineering.In the first study of this thesis,we started from a medical grade polyetheretherketone base material,modified the PEEK surface with a dopamine（PDA）coating,and then chelated a gradient concentration of Mg²⁺（0.02M,0.1M,0.5M）to obtain five groups of samples of unmodified PEEK,PEEK-PDA,PEEK-P-0.02,PEEK-P-0.1,and PEEK-P-0.5,respectively.We carried out a series of surface characterizations on five groups of samples including surface roughness,surface water contact angle,XPS,FT-IR,SEM,EDS,etc.The surface roughness and water contact angle were significantly improved before and after modification;XPS,FT-IR,SEM and EDS results showed that the PDA coating stably existed on the surface of PEEK-PDA,PEEK-P-0.02,PEEK-P-0.1,PEEK-P-0.5 samples,and Mg²⁺was successfully chelated into the PEEK-PDA surface.In addition,we also performed a series of in vitro biological characterizations on the five groups of samples,including cytotoxicity experiments,cell proliferation experiments,ARS,ALP,SBF simulated body fluid immersion,in vitro angiogenesis experiments.In vitro cytotoxicity experiments and osteogenesis experiments showed that PEEK-P-0.02 samples had good biocompatibility and the best in vitro osteogenesis.Antibacterial experiments showed that the introduction of PDA and Mg²⁺made the modified samples show antibacterial effects on both Staphylococcus aureus and Escherichia coli,and the sample s we prepared performed excellently in in vitro antibacterial experiments.In vitro angiogenesis experiments showed that the amount of angiogenesis on the surface of PEEK-PDA samples was significantly higher than that of PEEK samples,and the amount of angiogenesis on the surfaces of PEEK-P-0.02 samples was further increased than that of PEEK-PDA samples.In conclusion,our modified polyetheretherketone has excellent biocompatibility,in vitro osteogenesis,in vitro angiogenesis,in vitro antibacterial and other properties,and is expected to become a new type of human body to deal with bone tissue damage.Bone Implant Materials.In the second study of this thesis,starting from the synthesis of polyamic acid,we prepared four groups of PEEK/PI gas condensate by doping polyetheretherketone powder with different contents（0,2.5%,5%,7.5%）aerogel,named ODA-0,ODA-25,ODA-50,ODA-75.The above four groups of samples were characterized by elastic modulus,Porous Structure Analysis,SEM,FT-IR,etc.The results showed that the elastic modulus of the ODA-75 sample was two times higher than that of the ODA-0 sample.It is proved that the pore size of ODA-75,ODA-50,ODA-25 samples is about two times lower than that of ODA-0,and FT-IR proves stable PEEK in ODA-25,ODA-50,ODA-75 samples.In addition,we performed in vitro biological tests on the surface of ODA-0,ODA-25,ODA-50,and ODA-75 samples,such as cytotoxicity,biocompatibility,ARS,and SBF simulated body fluid immersion experiments.The experimental results show that the addition of PEEK makes the porosity of the modified aerogel smaller,which is easy for cell attachment,and the biocompatibility is significantly improved.The simulated body fluid immersion experiments of ARS and SBF showed that the addition of PEEK increased the osteogenic properties of the modified samples in vitro.In summary,the above studies show that the PEEK-modified PI aerogel prepared by us has a significant increase in the elastic modulus,the surface pores can reach the nm level,and the modified sample has good biocompatibility and in vitro osteogenic performance,which indicates that our prepared PEEK-modified PI aerogel is a potential artificial bone material with high elastic modulus,low density,good biocompatibility and excellent osteogenesis.