Clèries L, Fernández-Pradas J M, Sardin G, Morenza J L
Departament de Física Aplicada Optica, Universitat de Barcelona, Spain.
Biomaterials. 1998 Aug;19(16):1483-7. doi: 10.1016/s0142-9612(98)00063-5.
Pulsed laser deposited calcium phosphate coatings on titanium alloy have been tested under simulated physiological conditions in order to evaluate the changes in morphology, composition and structure. The coatings were deposited under different conditions to obtain different crystalline structures, ranging from amorphous and mixed crystalline phases to pure crystalline hydroxyapatite (HA). The coated samples were immersed in a Ca-free Hank's balanced salt solution for up to 5 days. Characterization of the coatings was performed by X-ray diffraction, scanning electron microscopy and Fourier-transform Raman spectroscopy before and after immersion. Their dissolution behaviour was also monitored through their mass loss and calcium release. Coatings of pure HA preserve their morphology and structure during the exposure time in solution. In multiphasic coatings, consisting of HA with tetracalcium phosphate (TetraCP) or beta-tricalcium phosphate (beta-TCP) with a-tricalcium phosphate (alpha-TCP), microporosity is induced by the complete dissolution of TetraCP or gamma-TCP. Amorphous calcium phosphate coatings totally dissolve.
为了评估形态、成分和结构的变化，已在模拟生理条件下对脉冲激光沉积在钛合金上的磷酸钙涂层进行了测试。在不同条件下沉积涂层以获得不同的晶体结构，范围从非晶态和混合晶相到纯晶态羟基磷灰石（HA）。将涂覆的样品浸入无钙的汉克平衡盐溶液中长达5天。在浸泡前后，通过X射线衍射、扫描电子显微镜和傅里叶变换拉曼光谱对涂层进行表征。还通过质量损失和钙释放监测它们的溶解行为。纯HA涂层在溶液中的暴露时间内保持其形态和结构。在由HA与磷酸四钙（TetraCP）或β-磷酸三钙（β-TCP）与α-磷酸三钙（α-TCP）组成的多相涂层中，TetraCP或γ-TCP的完全溶解会诱导微孔形成。非晶态磷酸钙涂层完全溶解。
