| Porous scaffold material is a critical factor for tissue engineering. It serves as a synthetic extracellular matrix (EMC) to support cell growth and tissue development. It takes effect on offering structure-support and template for tissue cells. It provides the environment for cell survival, growth, differentiation and proliferation and guides tissue regeneration and controls tissue structure. Therefore, it is important to find a scaffold material which can not only provide excellent biocompatibility and biodegradability but also possess special shapes and interconnected three-dimensional pores. Three-dimensional porous bio-ceramic scaffold material which was prepared by compounding of hydroxyapatite (HAP) and 6-tricalcium phosphate (β-TCP) with excellent biocompatibility and biodegradability has broad application prospects in tissue engineering fields, such as cartilage, bone etc..In this paper, HAP powder was prepared by aqueous method. The synthesis conditions as well as the properties of HAP powder were studied at first. Then, as prepared HAP powder was adopted as raw material to form ceramic slurry, the multi-phase (HAP and β-TCP) porous ceramic scaffold material was prepared via polymer foam impregnation and micro-wave foaming and pertinent heat-treatment. The optimized process of porous ceramic scaffold material preparation was investigated by cross experiment method. Meanwhile, the HAP powder was characterized by DSC/TG, IR, XRD and granulometry measurements. Further, the phase distribution, microstructure, porosity, mechanical property and distribution of pore size of porous ceramic scaffold material were systematically characterized via XRD, SEM, Archimedes principle, lever principle, mathematical statistics method etc.. Besides, the biodegradability and biocompatibility of multi-phase porous ceramic scaffold materials were investigated preliminarily by simulated biodegradation experiments and mesenchymal stem cells cultivation experiments in vitro.It was showed that the high-purity HAP powder with grain size range from 1μm 10μm could be fabricated by aqueous method through the thermodynamics system of Ca(NO3)2 — (NH4)2HPO4 —NH4OH—H2O via controlling pH value at 1011, keeping reaction more than 8 hours about 45℃, then the precipitate was heat-treated 5hours at 750"C after ageing, washing, filtering and drying. The multi-phase (HAP and 6-TCP) porous ceramic scaffold materials with porosity of 7585% and mechanical strength of 0.3MPa0.9MPa could be prepared after being sintered more than 4 hours at 1275'C1300''C via polymer foam impregnation and micro-wave foaming. The macroscopic pore size distribution of this porous ceramic scaffold material sintered 4 hours at 1225 °C was between lOQwrn and 800/*m and microscopic pore size was range from lfim to 5/im. While the pore size of this porous ceramic scaffold material sintered 4 hours at 1300°C was range from 10/mi to 500/on. The scaffold materials possessed interconnected three-dimensional pore structure. The porous ceramic scaffold materials with different ratio of HAP and 6-TCP could be designed and prepared by controlling sintering temperature at 1225X?<sup>1350*C and sintering time around 2-8 hours. This porous scaffold materials prepared in different sintering temperature possessed different dissolving biodegradability in vitro. But with rising of sintered temperature, the content of 8-TCP and the dissolving biodegradability were increased. The mesenchymal stem cells could grow on the porous ceramic scaffold materials in cultivation experiments in vitro. It is indicated that the porous ceramic scaffold materials have non-toxicity and biocompatibility. |
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