Biomimetic apatite-based biomaterials: on the critical impact of synthesis and post-synthesis parameters
Biomimetic apatite-based biomaterials: on the critical impact of synthesis and post-synthesis parameters
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DOI：
10.1007/s10856-012-4719-y
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发表时间：
2012-11-01
影响因子：
3.7
通讯作者：
Drouet, Christophe
中科院分区：
文献类型：
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作者：
Vandecandelaere, Nicolas;Rey, Christian;Drouet, Christophe
纳米晶磷灰石是硬组织的主要成分，世界各地都在尝试制备合成类似物。然而，合成/合成后参数的影响往往被忽视。基于对此类化合物的最新了解，我们考察了合成参数（成熟时间、温度、pH值、反离子性质）和后处理（在水介质中再浸泡、热处理）对其理化特性的影响。在成熟的前3天，我们注意到巨大的变化，在那里，我们观察到磷灰石阶段（位于纳米晶体的核心）逐渐向化学计量方向演化，而非磷灰石表面层逐渐消失。在温度升高的情况下，也证明了类似的趋势，在20-100摄氏度的范围内进行了研究。pH对化学成分的影响更具体。初始磷酸盐中反离子的性质影响其组成和非化学计量，这取决于它被纳入晶格的能力。冷冻干燥可以保持高的表面反应性，尽管在重新浸泡后会注意到进一步的演变。对干燥样品进行热处理的结果表明，纳米晶体上的水合层发生了变性。这项工作强调了对仿生磷灰石生产的合成/合成后参数进行良好控制的必要性。
Nanocrystalline apatites are major constituents of hard tissues, and attempts are made worldwide to prepare synthetic analogs. However the impact of synthesis/postsynthesis parameters is often disregarded. Based on an updated knowledge on such compounds, we inspected the effects of synthesis parameters (maturation time, temperature, pH, nature of counter-ions) and post-treatments (re-immersion in aqueous media, thermal treatment) on physicochemical characteristics. Great modifications were noticed during the 3 first days of maturation, where a progressive evolution of the apatite phase (localized in the core of the nanocrystals) toward stoichiometry was observed at the expense of the non-apatitic surface layer which progressively disappears. Similar trends were also evidenced for maturation run under increasing temperatures, studied here in the range 20-100 degrees C. pH impacted more specifically the chemical composition. The nature of the counter-ion in the starting phosphate salt influenced composition and nonstoichiometry, depending on its (in)ability to be incorporated in the lattice. Freeze-drying allowed to preserve a high surface reactivity, although further evolutions were noticed after re-immersion. Effects of a thermal treatment of dried samples were unveiled, suggesting a denaturation of the hydrated layer on the nanocrystals. This work underlines the necessity of a good control of synthesis/postsynthesis parameters for the production of biomimetic apatites.