Tanaka Manabu, Haniu Hisao, Kamanaka Takayuki, Takizawa Takashi, Sobajima Atsushi, Yoshida Kazushige, Aoki Kaoru, Okamoto Masanori, Kato Hiroyuki, Saito Naoto
Department of Orthopaedic Surgery, School of Medicine, Shinshu University, Asahi 3-1-1, Matsumoto, Nagano 390-8621, Japan.
Institute for Biomedical Sciences, Shinshu University, Asahi 3-1-1, Matsumoto, Nagano 390-8621, Japan.
Materials (Basel). 2017 Jan 3;10(1):33. doi: 10.3390/ma10010033.
The unidirectional porous hydroxyapatite HAp (UDPHAp) is a scaffold with continuous communicated pore structure in the axial direction. We evaluated and compared the ability of the UDPHAp as a three-dimensional (3D) bone tissue engineering scaffold to the interconnected calcium porous HAp ceramic (IP-CHA). To achieve this, we evaluated in vitro the compressive strength, controlled rhBMP-2 release behavior, adherent cell morphology, cell adhesion manner, and cell attachment of UDPHAp. As a further in vivo experiment, UDPHAp and IP-CHA with rhBMP-2 were transplanted into mouse calvarial defects to evaluate their bone-forming ability. The Results demonstrated that the maximum compressive strengths of the UDPHAp was 7.89 ± 1.23 MPa and higher than that of IP-CHA (1.92 ± 0.53 MPa) ( = 0.0039). However, the breaking energies were similar (8.99 ± 2.72 vs. 13.95 ± 5.69 mJ, = 0.055). The UDPHAp released rhBMP-2 more gradually in vivo. Cells on the UDPHAp adhered tightly to the surface, which had grown deeply into the scaffolds. A significant increase in cell number on the UDPHAp was observed compared to the IP-CHA on day 8 (102,479 ± 34,391 vs. 32,372 ± 29,061 estimated cells per scaffold, = 0.0495). In a mouse calvarial defect model, the percentages of new bone area (mature bone + trabecular bone) in the 2x field were 2.514% ± 1.224% for the IP-CHA group and 7.045% ± 2.055% for the UDPHAp group, and the percentage was significantly higher in the UDPHAp group ( = 0.0209). While maintaining the same strength as the IP-CHA, the UDPHAp with 84% porosity showed a high cell number, high cell invasiveness, and excellent bone formation. We believe the UDPHAp is an excellent material that can be applied to bone regenerative medicine.
单向多孔羟基磷灰石（UDPHAp）是一种在轴向具有连续连通孔隙结构的支架。我们评估并比较了UDPHAp作为三维（3D）骨组织工程支架相对于相互连接的钙多孔羟基磷灰石陶瓷（IP-CHA）的能力。为此，我们在体外评估了UDPHAp的抗压强度、rhBMP-2的可控释放行为、贴壁细胞形态、细胞黏附方式以及细胞附着情况。作为进一步的体内实验，将含有rhBMP-2的UDPHAp和IP-CHA移植到小鼠颅骨缺损处，以评估它们的成骨能力。结果表明，UDPHAp的最大抗压强度为7.89±1.23MPa，高于IP-CHA（1.92±0.53MPa）（P = 0.0039）。然而，断裂能相似（8.99±2.72对13.95±5.69mJ，P = 0.055）。UDPHAp在体内能更缓慢地释放rhBMP-2。UDPHAp上的细胞紧密黏附于表面，并深入生长到支架内部。与第8天的IP-CHA相比，UDPHAp上的细胞数量显著增加（每个支架估计细胞数为102,479±34,391对32,372±29,061，P = 0.0495）。在小鼠颅骨缺损模型中，IP-CHA组在2倍视野下新骨面积（成熟骨+小梁骨）的百分比为2.514%±1.224%，UDPHAp组为7.045%±2.055%，UDPHAp组的百分比显著更高（P = 0.0209）。在保持与IP-CHA相同强度的同时，孔隙率为84%的UDPHAp显示出高细胞数量、高细胞侵袭性和优异的骨形成能力。我们认为UDPHAp是一种可应用于骨再生医学的优秀材料。
