Institute for Bioengineering of Catalonia, Baldiri Reixac 15-21, 08028 Barcelona, Spain.
J Mater Sci Mater Med. 2012 Oct;23(10):2509-20. doi: 10.1007/s10856-012-4705-4. Epub 2012 Jun 24.
Solution-mediated reactions due to ionic substitutions are increasingly explored as a strategy to improve the biological performance of calcium phosphate-based materials. Yet, cellular response to well-defined dynamic changes of the ionic extracellular environment has so far not been carefully studied in a biomaterials context. In this work, we present kinetic data on how osteoblast-like SAOS-2 cellular activity and calcium-deficient hydroxyapatite (CDHA) influenced extracellular pH as well as extracellular concentrations of calcium and phosphate in standard in vitro conditions. Since cells were grown on membranes permeable to ions and proteins, they could share the same aqueous environment with CDHA, but still be physically separated from the material. In such culture conditions, it was observed that gradual material-induced adsorption of calcium and phosphate from the medium had only minor influence on cellular proliferation and alkaline phosphatase activity, but that competition for calcium and phosphate between cells and the biomaterial delayed and reduced significantly the cellular capacity to deposit calcium in the extracellular matrix. The presented work thus gives insights into how and to what extent solution-mediated reactions can influence cellular response, and this will be necessary to take into account when interpreting CDHA performance both in vitro and in vivo.
由于离子取代而引起的溶液介导反应，正逐渐被探索为一种提高基于磷酸钙的材料的生物学性能的策略。然而，在生物材料背景下，细胞对离子细胞外环境的明确动态变化的反应迄今为止尚未得到仔细研究。在这项工作中，我们提供了动力学数据，说明成骨样 SAOS-2 细胞活性和缺钙羟基磷灰石 (CDHA) 如何影响细胞外 pH 以及在标准体外条件下细胞外钙和磷酸盐的浓度。由于细胞生长在允许离子和蛋白质通过的膜上，它们可以与 CDHA 共享相同的水相环境，但仍与材料物理分离。在这种培养条件下，观察到材料逐渐从培养基中吸附钙和磷酸盐对细胞增殖和碱性磷酸酶活性的影响很小，但细胞和生物材料之间对钙和磷酸盐的竞争显著延迟和降低了细胞在细胞外基质中沉积钙的能力。因此，这项工作深入了解了溶液介导反应如何以及在何种程度上影响细胞反应，这对于解释 CDHA 在体外和体内的性能是必要的。
