Sulfonated Polyetheretherketone Modified By Biomineralization Technology For Bone Repair

In the clinical work of orthopedics doctors,some common orthopedic diseases,such as bone tumor,congenital bone deformity,trauma or pathological fracture,infection and so on,may lead to the occurrence of CSD,and even further lead to osteoarthritis or other diseases,damage the normal musculoskeletal system.The gold standard of bone transplantation is autogenous bone transplantation.Only autogenous bone transplantation can achieve the best performance of bone transplantation materials,including bone conduction,bone induction and osteogenesis.However,autogenous bone transplantation needs to cause additional surgical trauma to patients,which not only causes the same pain as bone transplantation itself,but also has surgical complications such as bleeding,infection and so on.Moreover,the amount of autogenous bone we can obtain is extremely limited,which makes the reconstruction of bone defect morphology and function still face great challenges.More than 2 million patients in the world receive orthopedic bone transplantation every year.How to avoid the occurrence of bone defects and choose suitable bone defect fillers has become an important topic for our orthopedics doctors in clinical and scientific research,and bone tissue engineering has also emerged.Traditional bone defect repair materials and modern bone defect repair materials have been continuously studied and developed in the past decades,but they still have their own advantages and disadvantages.The new tissue engineering bone and composite materials also need to be improved and explored.Peek is a kind of linear aromatic polymer with good thermoplasticity,which has the advantages of radiation resistance,wear resistance and fatigue resistance.The light transmittance,wear resistance and mechanical properties similar to human bone of PEEK material have been widely concerned by orthopedics,neurosurgery and stomatology departments,and the material has also been used in clinical work.However,the biological inertia of PEEK is not conducive to cell adhesion,resulting in poor bone conduction and osseointegration.The ideal human bone defect repair materials in vivo is not only a simple space occupying and supporting role,but also can regulate the cell behavior to osteogenic differentiation and induction,promote the bulk repair of bone defects.The biological inertia of PEEK has become the biggest restriction to become an ideal bone defect repair materials.Therefore,how to improve the biological activity of PEEK and improve its osseointegration has become a research hotspot of PEEK as a bone defect repair material.In this experiment,sulfonated peek with controllable sulfonation degree was obtained by sulfur trioxide fumigation,and different pH value,mineralization time and concentration of SBF mineralizing solution were used for biomineralization of SBF mineralizing solution.Sulfonated peek with mineralized layer on the surface was successfully prepared.Firstly,the sulfonated peek obtained by sulfur trioxide fumigation was characterized,sulfonation degree,mechanical properties,cell proliferation,cell adhesion and extracellular matrix were determined;then the morphology of the obtained sulfonated peek after biomineralization was analyzed by scanning electron microscope,mechanical properties evaluation,cell proliferation,adhesion,osteogenic related staining and osteogenic gene expression Finally,the biocompatibility of the material and the osteogenic effect of the bone defect area were evaluated by using the rat skull defect model.Through the above studies,it is proved that sulfonated peek modified by biomineralization technology has good biocompatibility,mechanical properties and osteogenic induction ability.It provides a new research direction for bone repair materials.Part one: preparation and in vitro biological study of sulfonated peek with topological morphology:In this chapter,sulfonated peek with surface voids was obtained by fumigation with sulfur trioxide steam generated by the reaction of concentrated sulfuric acid and phosphorus pentoxide at 85 ?,and the void size was 10.32 ± 1.43 ? M.There was no significant difference in tensile strength between the two groups before sulfonation,and the cell proliferation and adhesion ability were improved compared with the blank group.After acellular treatment,the extracellular matrix can significantly improve cell proliferation and adhesion.Among them,fumigation for 30 minutes group showed the best performance in cell proliferation and adhesion.Part two: preparation and in vitro biological properties of sulfonated peek modified by biomineralization technology:108 groups with different mineralization degree were obtained by grouping different concentration(1,5,10 times),pH(5.4,6.4,7.4,8.4)and mineralization time(2h,4h,6h,12 h,24h,2D,7d,14 d,21d).After the degree of mineralization was confirmed by scanning electron microscope,the two groups with SBF 5 times of pH 6.4 and 7.4 for 14 days and the two groups with SBF 10 times of pH 6.4 and 7.4 for 14 days had good degree of mineralization.Then the surface Ca / P ratio was determined by XRD,and the mechanical properties,cell adhesion,osteogenic induction,staining and osteogenic gene expression were studied.The results showed that the sulfonated peek modified by biomineralization technology had good biocompatibility,mechanical properties and osteogenic induction ability,and its performance was significantly enhanced compared with that of sulfonated peek.Especially,the concentration of mineralized solution 10 times,pH 7.4,and mineralized time 14 days.The third part: the study of biomineralization modified sulfonated polyether ether ketone in vivo bone repair:In this chapter,the blank group peek in the first part,the sulfonation group for 30 minutes,and the four groups in the second part were used in the study of bone repair in vivo.The materials in each group were trimmed to 5mm in diameter and completely filled in the rat skull defect model.The osteogenic effect of each group in the process of bone repair was evaluated by micro CT three-dimensional reconstruction and histological analysis.The results showed that the new bone tissue extended and crawled along the surface of peek.After 8 weeks,the four groups of sulfonated peek modified by biomineralization showed good osteogenic performance,and the group with 10 times concentration of mineralized solution,pH value of 7.4 and mineralization time of 14 days had the best effect,which was consistent with the results of cell experiment in vitro.This method of bilateral modification can improve the biocompatibility,which provides a new direction for bone repair materials.