Institute for Bioengineering of Catalonia, Baldiri Reixac 15-21, 08028, Barcelona, Spain.
J Tissue Eng Regen Med. 2013 Aug;7(8):609-20. doi: 10.1002/term.550. Epub 2012 Apr 27.
In bone tissue engineering, the composition of the ionic extracellular environment (IEE) can determine both cellular fate and a biomaterial's development and performance. Therefore, precise control of the IEE and a perfect understanding of the dynamic changes that it can be subject to due to cellular activity is highly desired. To achieve this, we initially monitored how two standard osteoblast-like cell models that expressed either high or low alkaline phosphatase activity - SAOS-2 and MG63 cells, respectively - affected the extracellular concentrations of calcium and phosphate during long-term cultures. It was observed that cellular influence on the IEE varied greatly between the two models and could be linked to the capacity of cells to deposit calcium in the extracellular matrix. Miniaturized ion-selective electrodes that could allow for real-time monitoring of calcium in a minimally invasive way were then constructed. The electrodes were characterized in standard in vitro cell culture environments, prior to being successfully applied for periods of 24 h, to record the dynamics of cell-induced deposition of calcium in the extracellular matrix, while using osteogenic media of either high or low concentrations of phosphate. As a result, this study provides the background and technological means for the non-destructive evaluation of the IEE in vitro and allows for the optimization and development of better models of bone tissue construction.
在骨组织工程中，离子细胞外环境 (IEE) 的组成可以决定细胞的命运和生物材料的发展和性能。因此，精确控制 IEE 并充分了解由于细胞活动而可能发生的动态变化是非常需要的。为了实现这一目标，我们最初监测了两种表达高或低碱性磷酸酶活性的标准成骨样细胞模型——SAOS-2 和 MG63 细胞——在长期培养过程中如何影响细胞外钙和磷酸盐浓度。结果表明，细胞对 IEE 的影响在两种模型之间存在很大差异，并且可以与细胞在细胞外基质中沉积钙的能力相关联。然后构建了可以微创实时监测钙的小型化离子选择性电极。这些电极在标准的体外细胞培养环境中进行了表征，然后成功地应用了 24 小时，以记录细胞诱导细胞外基质中钙沉积的动力学，同时使用高或低磷酸盐浓度的成骨介质。因此，本研究为体外非破坏性评估 IEE 提供了背景和技术手段，并允许优化和开发更好的骨组织构建模型。
