Zhao Jing, Xiao Suguang, Lu Xiong, Wang Jianxin, Weng Jie
The Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, People's Republic of China.
Biomed Mater. 2006 Dec;1(4):188-92. doi: 10.1088/1748-6041/1/4/002. Epub 2006 Sep 13.
Various interconnected porous hydroxyapatite (HA) ceramic scaffolds are universally used to induct the tissue growth for bone repair and replacement, and serve to support the adhesion, transfer, proliferation and differentiation of cells. Impregnation of polyurethane sponges with a ceramic slurry is adopted to produce highly porous HA ceramic scaffolds with a 3D interconnected structure. However, high porosity always accompanies a decrease in the strength of the HA ceramic scaffolds. Therefore, it is significant to improve the strength of the HA ceramic scaffolds with highly interconnected porosity so that they are more suitable in clinical applications. In this work, highly porous HA ceramic scaffolds are first produced by the polymer impregnation approach, and subsequently further sintered by hot isostatic pressing (HIP). The phase composition, macro- and micro-porous structure, sintering and mechanical properties of the porous HA scaffolds are investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), nanoindentation analysis and compressive test. The experimental results show that the nanohardness and compressive strength of HIP-sintered porous HA ceramics are higher than those of commonly sintered HA scaffolds. The HIP technique can effectively improve the sintering property and densification of porous HA ceramic scaffolds, so inducing an increase in the compression strength.
各种相互连接的多孔羟基磷灰石（HA）陶瓷支架被广泛用于诱导组织生长以进行骨修复和替代，并用于支持细胞的黏附、迁移、增殖和分化。采用陶瓷浆料浸渍聚氨酯海绵的方法来制备具有三维相互连接结构的高孔隙率HA陶瓷支架。然而，高孔隙率往往伴随着HA陶瓷支架强度的降低。因此，提高具有高度相互连接孔隙率的HA陶瓷支架的强度具有重要意义，以便它们更适合临床应用。在这项工作中，首先通过聚合物浸渍法制备高孔隙率HA陶瓷支架，随后通过热等静压（HIP）进一步烧结。通过X射线衍射（XRD）、扫描电子显微镜（SEM）、纳米压痕分析和压缩试验研究了多孔HA支架的相组成、宏观和微观孔隙结构、烧结和力学性能。实验结果表明，HIP烧结的多孔HA陶瓷的纳米硬度和抗压强度高于普通烧结的HA支架。HIP技术可以有效地改善多孔HA陶瓷支架的烧结性能和致密化程度，从而导致抗压强度增加。
