Study On Performance Optimization Of Zinc-silicon Calcium Phosphate Bioactive Ceramics

An ideal bone tissue engineering scaffold is designed to mimic the structure and biological function of healthy bone tissue,including chemical composition and hierarchical structure and properties.The development of bone repair materials with both excellent biological activity and good mechanical properties has always been one of the research hotspots in orthopaedic clinical practice.Calcium silicate phosphate bioceramics have received extensive attention as artificial bone materials in recent years due to their good osteogenic activity.In this subject,the zinc-doped calcium silicate phosphate bioceramics（Ca₅（PO₄）₂Si O₄,CPS）bone repair material（Zn-CPS）with good biocompatibility was used as the research object to study the properties of calcium silicate phosphate powder and zinc metasilicate（Zn Si O₃）doping on the microstructure and properties of Zn-CPS bioceramics,and the related mechanisms are discussed.The main findings are as follows:（1）Influence of properties of calcium silicate phosphate powder on properties of Zn-CPS bioactive ceramicsCPS powders with different properties were prepared by sol-gel and ultrasonic-assisted precipitation methods,respectively,and the effects of different powder properties on the properties of Zn-CPS bioactive ceramics were studied.The research results show that the CPS powder prepared by sol-gel method,the powder with a lower calcination temperature has a smaller particle size.The refinement of the particle size of CPS powder can not only effectively improve the flexural strength of Zn-CPS,but also make Zn-CPS have better apatite deposition ability.The CPS powder prepared by sol-gel method calcined at 1200℃has good sintering performance and biological activity.The flexural strength of the Zn-CPS ceramic prepared from it can reach 97.9MPa,which has good apatite induction ability in PBS.It is a kind of bone regeneration material with good potential application prospect.（2）Influence of Zn Si O₃ doping on the properties of calcium silicate phosphate bioceramics bioactive ceramicsZn Si-CPS bioceramics with different contents were prepared by using CPS powder prepared by sol-gel method and using Zn Si O₃ powder as additive.The results show that zinc metasilicate doping can significantly promote the sintering of CPS ceramics.Zn Si-CPS ceramics are composed of CPS phase and HT phase at grain boundaries.Among them,the flexural strength of 3-Zn Si-CPS ceramics can reach up to 101MPa,which is 2.3 times of the flexural strength of pure calcium silicate phosphate bioceramics.However,after the Zn Si-CPS ceramics soaked in PBS for 28days,the surface shape has not changed significantly,and the p H value is stable between 7.4～7.6,indicating that the addition of Zn Si O₃ inhibits the in vitro degradation of Zn Si-CPS ceramics in PBS.