Lu Xiong, Leng Yang
Department of Mechanical Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong.
Biomaterials. 2004 May;25(10):1779-86. doi: 10.1016/j.biomaterials.2003.08.028.
Formation of calcium phosphate on alkali- and heat-treated titanium surfaces was investigated using transmission electron microscopy (TEM). The samples were prepared by immersing the alkali- and heat-treated titanium in a revised simulated body fluid (R-SBF) with the same HCO(3)(-) concentration level as in human blood plasma. The deposition and precipitation on treated titanium surfaces were extracted for TEM examination without thinning process. Electron diffraction of the precipitates revealed that octacalcium phosphate (OCP), instead of hydroxyapatite (HA), directly nucleates from amorphous calcium phosphate. The OCP crystals continuously grew on the titanium surfaces rather than transforming into apatite. Calcium titanate was also identified by electron diffraction. Its role in the formation bioactive calcium phosphate, however, is not clear from this experiment.
利用透射电子显微镜（TEM）研究了碱处理和热处理钛表面磷酸钙的形成。通过将碱处理和热处理后的钛浸入与人体血浆中HCO(3)(-)浓度水平相同的改良模拟体液（R-SBF）中来制备样品。在不进行减薄处理的情况下，提取处理过的钛表面上的沉积物和沉淀物用于TEM检查。沉淀物的电子衍射表明，磷酸八钙（OCP）而非羟基磷灰石（HA）直接从无定形磷酸钙中形核。OCP晶体在钛表面持续生长，而不是转变为磷灰石。电子衍射也鉴定出了钛酸钙。然而，从该实验中尚不清楚其在生物活性磷酸钙形成中的作用。
