Fabrication of carbonate apatite blocks from octacalcium phosphate blocks through different phase conversion mode depending on carbonate concentration
Fabrication of carbonate apatite blocks from octacalcium phosphate blocks through different phase conversion mode depending on carbonate concentration
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DOI：
10.1016/j.jssc.2018.08.008
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发表时间：
2018-11-01
影响因子：
3.3
通讯作者：
Ishikawa, Kunio
中科院分区：
文献类型：
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作者：
Sugiura, Yuki;Ishikawa, Kunio
碳酸磷灰石（CO（3）Ap）是成熟骨的无机成分，可用作骨替代物而不是自体移植物。最近，由碳酸钙通过溶解-沉淀反应形成的100%纯CO（3）Ap颗粒已被用作骨的临床前体。在这项研究中，通过浸泡在NaHCO 3中，研究了从磷酸八钙（OCP）块中制备CO（3）Ap块的可行性，OCP是骨成分的类似物，并作为骨的前体。OCP嵌段的宏观结构在转化为CO（3）Ap时保留。此外，随着NaHCO 3浓度从0.0增加到2.0 mol/L，所得CO（3）Ap中的碳酸根含量增加，在最大NaHCO 3浓度下达到约14 wt%。当NaHCO 3浓度增加到0.5mol/L时，CO（3）Ap晶体的形貌发生变化：当NaHCO 3浓度较低时，晶体呈假晶片状，而当NaHCO 3浓度较高时，晶体形成约10 nm的颗粒。不同的相变模式取决于NaHCO 3浓度，与CO（3）Ap晶体形态密切相关，并与块体机械强度的降低有关。
Carbonate apatite (CO(3)Ap) is an inorganic component of mature bone and is used as bone substitute instead of autografts. Recently, 100% pure CO(3)Ap granules formed from calcium carbonate via a dissolution-precipitation reaction have been used as a clinical precursor for bone. In this study, the feasibility of fabricating blocks of CO(3)Ap from blocks of octacalcium phosphate (OCP), which is an analog of the bone composition and serves as a precursor for bone, was investigated by immersion in NaHCO3. The macroscopic structure of the OCP block was retained upon conversion to CO(3)Ap. In addition, as the NaHCO3 concentration increased from 0.0 to 2.0 mol/L, the carbonate content increased in the resulting CO(3)Ap, reaching approximate to 14 wt% at maximum NaHCO3 concentration. Moreover, the morphology of the CO(3)Ap crystals varied as the NaHCO3 concentration increased up to 0.5 mol/L: they were pseudomorphic plate-like when the NaHCO3 concentration was low but formed particles ranging similar to 10 nm in size at high NaHCO3 concentrations. The different phase transformation modes depended on NaHCO3 concentrations closely related to CO(3)Ap crystal morphology and were associated with a decrease in the mechanical strength of the block.