多孔羟基磷灰石椎间融合器制备工艺研究

Study on the fabrication process of porous hydroxyapatite interbody fusion cage

目的制备一种具有三维贯通孔隙结构的生物活性椎间融合器模型。方法选取羟基磷灰石粉体、聚乙二醇6000(PEG6000)、甲基纤维素(MC)和双氧水为原料,采用气体发泡法制孔成型,通过调节成型时加入不同的双氧水量调节孔隙率,烧结后得到多孔羟基磷灰石陶瓷,进一步进行切割加工后得到椎间融合器模型。结果随着成型时加入双氧水量的增加,5个样品组的孔隙率从(24.6±5.7)%增加到(78.4±2.3)%,其对应的抗压强度从(13.8±3.4)MPa降低到(0.6±0.1)MPa。表明通过控制成型时加入的双氧水量可调节样品的孔隙率,进一步调节其抗压强度。结论通过气体发泡法制备多孔羟基磷灰石陶瓷,成型时加入双氧水量为5 mL,聚乙二醇量为7 mL,甲基纤维素量为10 mL,温度为1 150℃时,烧结打磨后得到的椎间融合器模型孔隙率为57.7%,抗压强度为7.3 MPa,与成人胸腰椎椎体抗压强度相近,有望进一步应用于临床。

Objective To fabricate a bioactive interbody fusion cage model with three-dimensional pore structure. Methods Hydroxyapatite powder,polyethylene glycol 6000（ PEG6000）,methylcellulose（ MC） and hydrogen peroxide were selected as raw materials. Mold was prepared by gas foaming and the porosity was regulated by adjusting with different amount of hydrogen peroxide. The interbody fusion cage model was obtained after sintering and cutting. Results With the increase of hydrogen peroxide in molding process,the average porosities of the five sample groups was increased from（ 24. 6 ± 5. 7） % to（ 78. 4 ± 2. 3） %. The compressive strength was reduced from（ 13. 8 ± 3. 4） MPa to（ 0. 6 ± 0. 1） MPa,respectively. The above data indicates that with the decrease in the amount of hydrogen peroxide added while molding,the porosity is basically decreasing,while its compressive strength is increasing. Conclusion Porous hydroxyapatite ceramics were formed by gas foaming with adding 5 ml hydrogen peroxide,7 ml polyethylene glycol,and 10 ml methylcellulose. The sintering temperature was 1 150 ℃. The porosity and the compressive strength of interbody fusion cage model was 57. 7% and 7. 3 MPa. The compressive strength was similar to that of adult thoracolumbar vertebra. It is hopeful to be further applied to clinic.