Process of calcification on artificial materials
Process of calcification on artificial materials
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DOI：
10.1007/s003920170048
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
T. Kokubo;H.‐M. Kim;M. Kawashita;T. Nakamura
中科院分区：
文献类型：
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作者：
T. Kokubo;H.‐M. Kim;M. Kawashita;T. Nakamura
CaO、sio2基玻璃在非细胞模拟体液（SBF）中形成骨状磷灰石，其离子浓度几乎等于人血浆中的离子浓度。前一种玻璃的磷灰石形成归因于SBF中表面形成的Si-OH基团对磷灰石成核的催化作用。SiO2、TiO2、ZrO2、Ta2O5和nb2o5凝胶在SBF表面形成磷灰石，而al2o3凝胶则没有形成磷灰石。这说明除了Si-OH基团外，Ti-OH、Zr-OH、Ta-OH和Nb-OH基团也对磷灰石成核有促进作用，但Al-OH没有。在SBF中，以不同官能团末端的自组装单层上形成磷灰石，表明COOH和h2po4基团对磷灰石成核也有影响。所有这些基团都在pH值7.40左右带负电荷。它们的磷灰石成核能力随排列方式的不同而不同。在钛- oh基团中，锐钛矿结构的钛- oh基团对磷灰石成核最有效。附能色散x射线能谱仪的透射电子显微镜显示，这些官能团不是直接诱导磷灰石成核，而是通过它们的钙化合物的形成，随后形成低Ca/P原子比的无定形磷酸钙。
CaO, SiO2-based glasses form the bonelike apatite on their surfaces in an acellular simulated body fluid (SBF) with ion concentrations nearly equal to those of the human blood plasma. The apatite formation of the former glasses is attributed to the catalytic effect of the Si-OH groups, which are formed on their surfaces in SBF, for the apatite nucleation. The gels of SiO2, TiO2, ZrO2, Ta2O5, and Nb2O5formed the apatite on their surfaces in SBF, but Al2O3gel did not. This indicates that the Ti-OH, Zr-OH, Ta-OH and Nb-OH groups besides the Si-OH groups are also effective for the apatite nucleation, but Al-OH groups are not effective. Apatite formation on self-assembled monolayer terminated with various functional groups in SBF showed that COOH and H2PO4groups are also effective for the apatite nucleation. All these groups are negatively charged around pH 7.40. Their apatite nucleating ability is varied with their arrangements. Among the Ti-OH groups, those in anatase structure are most effective for the apatite nucleation. Transmission electron microscope attached with energy dispersive X-ray spectrometer showed that these functional groups induce the apatite nucleation not directly, but through formation of their calcium compounds and subsequent formation of amorphous calcium phosphate with low Ca/P atomic ratios.