Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, Centre for Biomedical Materials Applications and Technology, Singapore.
Biomaterials. 2010 Nov;31(33):8684-95. doi: 10.1016/j.biomaterials.2010.07.097. Epub 2010 Aug 24.
Bioreactors provide a dynamic culture system for efficient exchange of nutrients and mechanical stimulus necessary for the generation of effective tissue engineered bone grafts (TEBG). We have shown that biaxial rotating (BXR) bioreactor-matured human fetal mesenchymal stem cell (hfMSC) mediated-TEBG can heal a rat critical sized femoral defect. However, it is not known whether optimal bioreactors exist for bone TE (BTE) applications. We systematically compared this BXR bioreactor with three most commonly used systems: Spinner Flask (SF), Perfusion and Rotating Wall Vessel (RWV) bioreactors, for their application in BTE. The BXR bioreactor achieved higher levels of cellularity and confluence (1.4-2.5x, p < 0.05) in large 785 mm(3) macroporous scaffolds not achieved in the other bioreactors operating in optimal settings. BXR bioreactor-treated scaffolds experienced earlier and more robust osteogenic differentiation on von Kossa staining, ALP induction (1.2-1.6×, p < 0.01) and calcium deposition (1.3-2.3×, p < 0.01). We developed a Micro CT quantification method which demonstrated homogenous distribution of hfMSC in BXR bioreactor-treated grafts, but not with the other three. BXR bioreactor enabled superior cellular proliferation, spatial distribution and osteogenic induction of hfMSC over other commonly used bioreactors. In addition, we developed and validated a non-invasive quantitative micro CT-based technique for analyzing neo-tissue formation and its spatial distribution within scaffolds.
生物反应器为有效交换营养物质和机械刺激提供了一个动态的培养系统，这对于生成有效的组织工程骨移植物（TEBG）是必要的。我们已经表明，双轴旋转（BXR）生物反应器成熟的人胎儿间充质干细胞（hfMSC）介导的 TEBG 可以治愈大鼠临界尺寸股骨缺损。然而，目前尚不清楚是否存在用于骨 TE（BTE）应用的最佳生物反应器。我们系统地比较了这种 BXR 生物反应器与三种最常用的系统：旋转瓶（SF）、灌注和旋转壁容器（RWV）生物反应器，以评估它们在 BTE 中的应用。BXR 生物反应器在较大的 785mm³大孔支架中实现了更高的细胞密度和融合度（1.4-2.5 倍，p<0.05），而其他在最佳条件下运行的生物反应器则无法实现。BXR 生物反应器处理的支架在 von Kossa 染色、碱性磷酸酶诱导（1.2-1.6 倍，p<0.01）和钙沉积（1.3-2.3 倍，p<0.01）方面更早、更稳健地经历成骨分化。我们开发了一种 Micro CT 定量方法，该方法证明 hfMSC 在 BXR 生物反应器处理的移植物中均匀分布，但在其他三种中则不然。BXR 生物反应器能够促进 hfMSC 的细胞增殖、空间分布和成骨诱导，优于其他常用的生物反应器。此外，我们开发并验证了一种基于非侵入性定量 Micro CT 的技术，用于分析支架内新组织的形成及其空间分布。
