Study On Tailorable Mechanics-Degradability Of 3D Printing Porous Bioceramic Scaffolds

Due to the increase of bone traumas and diseases,the biocompatible and biodegradable biomaterials required for different clinical bone transplantation have been paid close attention by researchers.In this paper,magnesium-doped wollastonite bioceramic scaffolds with core-shell structure(CSi,CSi-Mg4,CSi-Mg10,CSi@CSi-Mg10,CSi-Mg10@CSi,CSi-Mg10@CSi-Mg4,CSi-Mg4@ CSi-Mg10)were prepared by 3D printing technique via conventional single and coaxial core-shell structure printing nozzle,and the mechanics and the degradation of non-stoichiometric wollastonite porous ceramic scaffolds can be controlled and tailored.The results show that the low dose magnesium and strontium doped wollastonite powders prepared by wet chemical process maintain a stable wollastonite phase.Uneven distribution of different Mg doping ratio in core-shell structure has a significant effect on the compressive strength of bioceramic scaffolds,especially the higher Mg doped in shell layer,the stronger of the scaffolds compressive strength and the lower degradation rate.The physical and chemical properties of porous wollastonite ceramics can be significantly adjusted by different dosages of magnesium doping,and the degradation rate of scaffold can be controlled.Secondly,pore forming agent is added into the scaffold shell,and the core layer is doped with strontium ions,so that different components of the core-shell structure can be degraded and released as required simultaneously during the degradation process.In the degradation process,the shell pores ensure that the nuclear component strontium-doped wollastonite can also be degraded regularly,and the calcium,silicon,magnesium and strontium ions can be released in controlled according to the bone regeneration process.In this thesis,the dorsal muscle embedding animal model experiments showed that strontium ions in the nuclear layer were also involved in the early vascularization of scaffolds.In conclusion,this thesis preliminarily demonstrated the feasibility and reliability of 3D printing core-shell bioactive porous ceramic scaffolds with adjustable component distribution and controllable internal microstructure.It not only expands the function of 3D printing technology,but also realizes the simultaneous optimization of physicochemical,mechanical and biological properties of a new generation biomaterials,which leads a new way of biomaterials with different clinical indications...