三种多孔磷酸钙陶瓷制备方法的比较研究

The Comparative Study for Fabricating Porous Ceramics of Phosphate Calcium with Three Different Methods

目的以磷酸钙双相陶瓷为材料,采用3种成型方法制备多孔生物陶瓷支架,比较不同制备方法所获得的多孔陶瓷的孔结构,为骨组织工程提供适合的支架材料。方法本实验用不同配比的H_2O和SiO_2溶胶配制浆料,以添加致孔剂法、冷冻干燥法及有机泡沫浸渍法制备陶瓷坯体,经高温烧结得到多孔双相陶瓷支架。通过扫描电镜(SEM)观察了陶瓷块的孔结构、孔径及孔的连通性。同时,检测了多孔陶瓷的气孔率及力学强度,从而评价其作为骨组织工程支架材料的可行性。结果本研究采用的3种制备方法获得的多孔陶瓷,均具有连通的孔结构。添加致孔剂法获得陶瓷的孔径为72±30μm,气孔率为92.3%;冷冻干燥法获得的陶瓷孔径较小(23-47μm),气孔率为74%～87%;有机泡沫浸渍法制备出的孔径最大(164±46μm),气孔率为90.2%。力学强度测试结果显示,有机泡沫浸渍法制备的多孔陶瓷的抗压强度最大(71±18 KPa);添加致孔剂法其次,抗压强度为18±5 KPa;冷冻干燥法获得的多孔陶瓷抗压强度为14-44 KPa,抗压强度最低。结论3种制备方法均能够制备出具有连通孔结构的高气孔率的多孔磷酸钙陶瓷,以有机泡沫浸渍法和添加致孔剂法制备的多孔陶瓷力学强度较高.更适合作为骨组织工程支架材料。

Objective To prepare porous based on biphasic phosphate calcium ceramic scaffolds using three different methods and compare pore structure of the porous ceramics obtained, with the purpose of providing suitable scaffold for the application of bone tissue engineering. Methods The sol of different H2O/SiO2 ratio was prepared to gain green ceramics by adding porogen, freeze-drying and polymer sponge method. Porous biphasic ceramics were prepared after being sintered. The pore structure, pore diameter and connectivity were observed by scanning electron microscopy （SEM）. The porosity was measured by the Archimedes method and the mechanical strength of porous ceramics was detected using the universal mechanical tester. Results Porous ceramics prepared by the above three methods all had connecting pore structure. The pore diameter of the ceramics prepared by adding porogen method was 72±30 μm, and the average porosity was 92.3%. Pore diameter of porous ceramics obtained by freeze-drying method was 23-47μm and the porosity was 74%-87%. Among three fabricating methods, pore diameter of porous ceramics prepared by the polymer sponge method was the biggest, with 164±46 μm and the porosity was 90.2%. For mechanical strength, the compressive strength of porous ceramics prepared by the polymer sponge method was the biggest （71±18 KPa）. The compressive strength of ceramics obtained by the other two methods was relatively lower. Conclusion Porous ceramics prepared by three kinds of methods all possessed connecting pore structure and high porosity, but the mechanical strength of porous ceramics prepared by adding porogen and polymer sponge methods was higher. Adding porogen and polymer sponge methods could be suitable for the preparation of porous ceramic scaffolds in bone tissue engineering.