Effects of Flow Shear Stress and Mass Transport on the Construction of a Large-Scale Tissue-Engineered Bone in a Perfusion Bioreactor
Effects of Flow Shear Stress and Mass Transport on the Construction of a Large-Scale Tissue-Engineered Bone in a Perfusion Bioreactor
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DOI：
10.1089/ten.tea.2008.0540
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发表时间：
2009-10-01
影响因子：
4.1
通讯作者：
Dai, Kerong
中科院分区：
文献类型：
--
作者：
Li, Deqiang;Tang, Tingting;Dai, Kerong
目前，组织工程骨的构建主要采用体外灌注生物反应器。在灌注培养中，流体流动可以对接种在支架上的细胞施加剪切力，从而改善细胞的质量运输。本实验研究了流动剪切力和质量输运对以临界尺寸的β-磷酸三钙为支架，接种人骨髓间充质干细胞（hBMSCs）构建大规模组织工程骨的影响。这是通过改变流速和向培养基中加入葡聚糖来完成的，从而改变培养基的粘度。将细胞接种到支架上，并在灌注生物反应器中培养长达28天，具有不同的流体流动剪切应力或不同的质量输送。通过流体动力学模拟计算得到，传质速率为3 mL/min时，不同实验组的流动剪切应力分别为0.005 Pa（0.004-0.007 Pa）、0.011 Pa（0.009-0.013 Pa）、0.015 Pa（0.013-0.018 Pa）。当流动剪切力为0.013-0.018 Pa时，质量传递分别为3、6、9 mL/min。培养28 d后，通过hBMSCs的成骨分化和组织学检测来评价组织工程骨的构建。细胞外基质（ECM）分布在整个支架中，并在灌注培养28天后矿化。流动剪切力的增加促进了hBMSCs的成骨分化，并促进了ECM的矿化。然而，增加质量运输抑制矿化ECM的形成。因此，流动切应力和运输都影响着大规模组织工程骨的构建。在流体流动剪切力为0.015 Pa（0.013-0.018 Pa）、质量输送速率为3 mL/min的灌注式生物反应器中，可以较好地制备大规模的组织工程骨。
Currently, a tissue-engineered bone is usually constructed using a perfusion bioreactor in vitro. In the perfusion culture, fluid flow can exert shear stress on the cells seeded on scaffold, improving the mass transport of the cells. This experiment studied the effects of flow shear stress and mass transport, respectively, on the construction of a large-scale tissue-engineered bone using the critical-sized beta-tricalcium phosphate scaffold seeded with human bone marrow-derived mesenchymal stem cells (hBMSCs). This was done by changing flow rate and adding dextran into the media, thus changing the media's viscosity. The cells were seeded onto the scaffolds and were cultured in a perfusion bioreactor for up to 28 days with different fluid flow shear stress or different mass transport. When the mass transport was 3mL/min, the flow shear stress was, respectively, 0.005 Pa (0.004-0.007 Pa), 0.011 Pa (0.009-0.013 Pa), or 0.015 Pa (0.013-0.018 Pa) in different experiment group obtained by simulation and calculation using fluid dynamics. When the flow shear stress was 0.015 Pa (0.013-0.018 Pa), the mass transport was, respectively, 3, 6, or 9mL/min. After 28 days of culture, the construction of the tissue-engineered bone was assessed by osteogenic differentiation of hBMSCs and histological assay of the constructs. Extracellular matrix (ECM) was distributed throughout the entire scaffold and was mineralized in the perfusion culture after 28 days. Increasing flow shear stress accelerated the osteogenic differentiation of hBMSCs and improved the mineralization of ECM. However, increasing mass transport inhibited the formation of mineralized ECM. So, both flow shear stress and transport affected the construction of the large-scale tissue-engineered bone. Moreover, the large-scale tissue-engineered bone could be better produced in the perfusion bioreactor with 0.015 Pa (0.013-0.018 Pa) of fluid flow shear stress and 3mL/min of mass transport.