Preparation And Characterization Of Bioceramic With Tailorable Degradability

Due to the limitations of autologous bone applications,researchers have shifted their focus to artificial bone substitutes.Microsphere materials have become a typical form of bone repair materials in terms of their large surface area,good fluidity and filling characteristics.In this thesis,a self-designed platform for preparation was developed to form biodegradation-tailorable core-shell bioceramic particles doped with foreign ions.The analysis showed that it has uniform size,good spherical morphology and obvious component distribution.Immersion experiments showed that the microspheres have good biological activities but different degradation rates.The in vitro cell experiments and the New Zealand rabbit femur defect model showed that the microspheres have good cytocompatibility and bone-form activity;Moreover,the bone-form efficiency in animals were significantly diverse.Secondly,different magnesium-contained co-doped microspheres and core-shell microspheres as well as porous-shell microspheres were prepared by the similar technology.A series of physical and chemical properties evaluation showed that pore-forming can give a better solution to the problem of early degradation of core and the release of ions.Femoral defect models in rabbit showed that both the component distribution and the microstructure of shell affected the regeneration and ingrowth of new bone significantly.Thirdly,this thesis also explored the preparation and osteogenic activity of three-layered core-shell microspheres of tricalcium phosphate and wollastonite.Beagle dog femur defect model studies showed that the osteogenic activity of the composite microspheres was significantly better than pure microspheres used in current clinics,indicating that the composite bioceramic has great clinical potential.In summary,this thesis fully demonstrates the physical,chemical and biological properties of core-shell structured bioceramics with adjustable component distribution and microstructures.These results provide new alternatives for designing bone implant materials for specific clinical requirements and different conditions.