Honeycomb blocks composed of carbonate apatite, β-tricalcium phosphate, and hydroxyapatite for bone regeneration: effects of composition on biological responses
Honeycomb blocks composed of carbonate apatite, β-tricalcium phosphate, and hydroxyapatite for bone regeneration: effects of composition on biological responses
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DOI：
10.1016/j.mtbio.2019.100031
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发表时间：
2019-09-01
影响因子：
8.2
通讯作者：
Ishikawa, K.
中科院分区：
文献类型：
--
作者：
Hayashi, K.;Kishida, R.;Ishikawa, K.
在整形外科和牙科领域中需要表现出与自体骨相同的骨修复能力的合成支架。合适的合成骨移植替代物应诱导间充质干细胞的成骨分化、骨生成和血管生成。在这项研究中，三种类型的蜂窝块（HCB），由羟基磷灰石（HAp），β-磷酸三钙（TCP），和碳酸磷灰石（CO（3）Ap），和HCB的组成对骨形成和成熟的影响进行了研究。选择HC结构以促进细胞穿透和组织向内生长。HAp和β-TCP HCB是通过挤压成型然后烧结制成的。通过挤压成型、烧结和溶解-沉淀反应制备了CO（3）Ap六氯苯。这些HCB具有类似的大孔结构：所有窝藏均匀分布的大孔（类似于160 μ m），这些大孔是有规律地排列和单向渗透的块。此外，大孔的体积几乎相等（类似于0.15cm（3）/g）。CO（3）Ap、HAp和β-TCP HCB的压缩强度分别为22.8 +/- 3.5、34.2 +/- 3.3和24.4 +/- 2.4 MPa。由于蜂窝型大孔结构，这些HCB的压缩强度高于具有复杂三维或单向大孔结构的商业支架。值得注意的是，CO（3）Ap HCB移植的骨成熟明显快于β-TCP和HAp HCB移植，术后4周和12周时，CO（3）Ap HCB的成熟骨面积百分比分别是HAp和β-TCP HCB的14.3倍和4.3倍，7.5倍和1.4倍。骨成熟和形成的差异可能是由HCB周围钙离子浓度的差异引起的，这是由固有的材料再吸收行为和机制决定的;通常，CO（3）Ap仅通过骨细胞再吸收而被再吸收，HAp不被再吸收，即使在没有破骨细胞的情况下，β-TCP也迅速溶解。除了组成之外，在形成各种组成的HCB期间不可避免地产生的HC支柱的微孔结构可能有助于骨成熟和形成的差异。
Synthetic scaffolds exhibiting bone repair ability equal to that of autogenous bone are required in the fields of orthopedics and dentistry. A suitable synthetic bone graft substitute should induce osteogenic differentiation of mesenchymal stem cells, osteogenesis, and angiogenesis. In this study, three types of honeycomb blocks (HCBs), composed of hydroxyapatite (HAp), beta-tricalcium phosphate (TCP), and carbonate apatite (CO(3)Ap), were fabricated, and the effects of HCB composition on bone formation and maturation were investigated. The HC structure was selected to promote cell penetration and tissue ingrowth. HAp and beta-TCP HCBs were fabricated by extrusion molding followed by sintering. The CO(3)Ap HCBs were fabricated by extrusion molding followed by sintering and dissolution-precipitation reactions. These HCBs had similar macroporous structures: all harbored uniformly distributed macropores (similar to 160 mu m) that were regularly arrayed and penetrated the blocks unidirectionally. Moreover, the volumes of macropores were nearly equal (similar to 0.15 cm(3)/g). The compressive strengths of CO(3)Ap, HAp, and beta-TCP HCBs were 22.8 +/- 3.5, 34.2 +/- 3.3, and 24.4 +/- 2.4 MPa, respectively. Owing to the honeycomb-type macroporous structure, the compressive strengths of these HCBs were higher than those of commercial scaffolds with intricate three-dimensional or unidirectional macroporous structure. Notably, bone maturation was markedly faster in CO(3)Ap HCB grafting than in beta-TCP and HAp HCB grafting, and the mature bone area percentages for CO(3)Ap HCBs at postsurgery weeks 4 and 12 were 14.3- and 4.3-fold higher and 7.5- and 1.4-fold higher than those for HAp and beta-TCP HCBs, respectively. The differences in bone maturation and formation were probably caused by the disparity in concentrations of calcium ions surrounding the HCBs, which were dictated by the inherent material resorption behavior and mechanism; generally, CO(3)Ap is resorbed only by osteoclastic resorption, HAp is not resorbed, and beta-TCP is rapidly dissolved even in the absence of osteoclasts. Besides the composition, the microporous structure of HC struts, inevitably generated during the formation of HCBs of various compositions, may contribute to the differences in bone maturation and formation.