Zhang Faming, Chang Jiang, Lu Jianxi, Lin Kaili, Ning Congqin
Biomaterials and Tissue Engineering Research Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China.
Acta Biomater. 2007 Nov;3(6):896-904. doi: 10.1016/j.actbio.2007.05.008. Epub 2007 Jun 26.
The major problem with the use of porous bioceramics as bone regeneration grafts is their weak mechanical strength, which has not been overcome to date. Here we described a novel way to solve this problem. Beta-tricalcium phosphate (beta-TCP) bioceramics with a bioinspired structure were designed and prepared with a porous cancellous core (porosity: 70-90%) inside and a dense compact shell (porosity: 5-10%) outside that mimics the characteristics of natural bone. They showed excellent mechanical properties, with a compressive strength of 10-80MPa and an elastic modulus of 180MPa-1.0GPa, which could be tailored by the dense/porous cross-sectional area ratio obeying the rule of exponential growth. The in vitro degradation of the bioinspired bioceramics was faster than that of dense bioceramics but slower than that of porous counterparts. The changes in mechanical properties of the bioinspired ceramics during in vitro degradation were also investigated. A concept of the bioinspired macrostructure design of natural bone was proposed which provided a simple but effective way to increase the mechanical properties of porous bioceramics for load-bearing bone regeneration applications. It should be readily applicable to other porous materials.
使用多孔生物陶瓷作为骨再生移植物的主要问题是其机械强度较弱，这一问题至今尚未得到解决。在此，我们描述了一种解决该问题的新方法。设计并制备了具有仿生结构的β-磷酸三钙（β-TCP）生物陶瓷，其内部为多孔松质核心（孔隙率：70-90%），外部为致密的密质壳（孔隙率：5-10%），模仿了天然骨的特征。它们表现出优异的机械性能，抗压强度为10-80MPa，弹性模量为180MPa-1.0GPa，可通过遵循指数增长规律的致密/多孔横截面积比进行调整。仿生生物陶瓷的体外降解速度比致密生物陶瓷快，但比多孔生物陶瓷慢。还研究了仿生陶瓷在体外降解过程中的力学性能变化。提出了天然骨仿生宏观结构设计的概念，为提高多孔生物陶瓷在承重骨再生应用中的力学性能提供了一种简单而有效的方法。它应该很容易应用于其他多孔材料。
