Padilla S, Román J, Sánchez-Salcedo S, Vallet-Regí M
Departamento de Química Inorgánica y Bioinorgánica, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain.
Acta Biomater. 2006 May;2(3):331-42. doi: 10.1016/j.actbio.2006.01.006. Epub 2006 Mar 24.
Materials obtained by the heat treatment of mixtures of hydroxyapatite (HA) and a silicate-based glass of the system SiO(2)-CaO-P(2)O(5) have been investigated. The influence of the glass content on the porosity, microstructure and on the constituent phases of the final materials was studied. The influence of these factors on the in vitro bioactive behaviour of the obtained materials was also investigated. In addition, an in vitro biocompatibility assay with osteoblastic-like cells was carried out. The addition of the glass to HA induced different solid-state reactions that yield the transformation of HA into alpha- and beta-tricalcium phosphate as well as the formation of silicon-containing phases (silicocarnotite or pseudowollastonite). In these mixtures an enhancement in the porosity, pore size and a heterogeneous microstructure was observed, compared with the precursors. As the sol gel glass content increased, the previous effects were higher. The materials showed the formation of an apatite-like layer on their surface when soaked in simulated body fluid, being faster in the sample with a higher content of glass. The formation of the new layer began in preferential zones in both samples, depending on the different reactivity of the crystalline phases formed. A synergistic effect between HA and glass was observed, showing in the mixtures a faster bioactive behaviour than in HA and glass themselves. The obtained materials allow a good attachment, spread and proliferation of the osteoblastic-like cells and no cytotoxic effect was observed.
对通过羟基磷灰石（HA）与SiO(2)-CaO-P(2)O(5)体系的硅酸盐基玻璃混合物进行热处理所获得的材料进行了研究。研究了玻璃含量对最终材料的孔隙率、微观结构和组成相的影响。还研究了这些因素对所得材料体外生物活性行为的影响。此外，还进行了与成骨样细胞的体外生物相容性测定。向HA中添加玻璃会引发不同的固态反应，这些反应会使HA转变为α-和β-磷酸三钙，并形成含硅相（硅钙石或假硅灰石）。与前驱体相比，在这些混合物中观察到孔隙率、孔径增加以及微观结构不均匀。随着溶胶-凝胶玻璃含量的增加，上述影响更为明显。将材料浸泡在模拟体液中时，其表面会形成类似磷灰石的层，玻璃含量较高的样品中形成速度更快。在两个样品中，新层的形成都始于优先区域，这取决于所形成的晶相的不同反应性。观察到HA和玻璃之间存在协同效应，混合物中的生物活性行为比HA和玻璃本身更快。所得材料有利于成骨样细胞的良好附着、铺展和增殖，且未观察到细胞毒性作用。
