非化学计量羟基磷灰石骨水泥的制备及性能研究

采用磷酸四钙和磷酸氢钙混合粉末制备了nCa/nP比为1.58的非化学计量羟基磷灰石骨水泥(n-HAC)及其多孔支架材料。结果表明:与nCa/nP=1.67的化学计量羟基磷灰石骨水泥(HAC)相比,n-HAC的凝结时间和抗压强度没有明显的区别。XRD和IR显示:n-HAC与HAC都为羟基磷灰石结构,但n-HAC在Tris-HCl缓冲溶液的降解性明显大于HAC。细胞培养结果表明:成骨细胞在n-HAC和HAC两种材料上的粘附和细胞形态没有明显的区别,但细胞在n-HAC上的增殖率明显高于HAC。将多孔n-HAC支架材料植入兔股骨缺损处,观察其修复骨缺损情况,组织学分析结果表明:新生骨在多孔支架的表面形成,并长入其内部;n-HAC在体内的降解比HAC快,能明显地促进新骨生成。

Preparation and Properties of Nonstoichiometric Hydroxyapatite Cement

Nonstoichiometric hydroxyapatite cement (n-HAC) and its porous scaffold with calcium to phosphate (n_Ca/n_P) molar ratio of 1.58 were fabricated by using the mixed powders of tetracalcium phosphate and dicalcium phosphate anhydrous. The results showed that no significant differences for the setting time and compressive strength were found between n-HAC and stoichiometric hydroxyapatite cememt (HAC) with n_Ca/n_P ratio of 1.67. The XRD and IR results revealed that both n-HAC and HAC were apatite structures. However, the degradation of n-HAC was faster than HAC in Tris-HCl solution. In cell cultural experiments, there were no significant differences for MG₆₃ cells attached on both n-HAC and HAC while the proliferation ratio of MG₆₃ cells on n-HAC was obviously higher than HAC. Both n-HAC and HAC scaffolds were implanted in rabbit femoral defects to study the repair of bone defects.The histological analysis results showed that the new bone tissue not only formed on the surfaces but also ingrew into the interior of the scaffolds. The biodegradation of n-HAC was faster than HAC scaffolds, which could obviously promote the formation of new bone tissue.