灌注式生物反应器中大段多孔磷酸三钙载体内流场分布的模拟研究

Simulation of flow field within large scale porous β-TCP scaffold in perfusion bioreactor

目的对灌注式生物反应器中大段多孔磷酸三钙载体内流场分布进行模拟研究。方法使用计算流体动力学(computational fluid dynamics,CFD)方法对我们自行设计的灌注式生物反应器中大段多孔β-TCP载体内流场分布情况进行了模拟研究,并对不同灌注速度条件下载体材料内的流体剪切应力进行了计算。结果利用CFD方法可以很好的模拟三维载体材料内的流场分布,并可以对载体材料内部的流体剪切应力进行计算。在我们的灌注反应体系中,3ml/min,6ml/min及9ml/min灌注速度条件下载体内主要区域的流速值分别为(0.227±0.062)mm/s、(0.459±0.125)mm/s以及(0.701±0.193)mm/s,而相应的流体剪切应力值分别为5.2±1.5mPa、10.6±3mPa以及16.2±4.6Pa。结论利用计算流体动力学(CFD)这一计算模型可以进行不同灌注系统之间结果的比较及不同显微结构载体之间结果的比较。并且可以根据细胞实验结果选择适于细胞分布增殖或者分化的流体剪切应力值,进而为组织工程中生物反应器的流速选择以及载体材料结构的加工提供依据。

Objecthe To simulate the flow field within large scale porous β-TCP scaffold in perfusion bioreactor. Method The computational fluid dynamics （CFD） method was used to simulate the flow conditions within large scale porous β-TCP scaffold in our newly designed perfusion bioreactor. The velocity field and the flow shear stresses within the scaffold at different perfusion flow rates were estimated by our simulation model. Result The velocity field and the flow shear stress throughout the scaffold could be well simulated with this method. The corresponding flow velocities in the scaffold pores at flow rate of 3 ml/min, 6 ml/min and 9 ml/ min were （0227±0.062） mm/s, （0.459±0.125） mm/s and （0.701±0.193） mm/s. The flow shear stresses within the scaffold at flow rate of 3 ml/min, 6 ml/min and 9 ml/min were 52 ± 1.5 mPa, 1.06 ±3 mPa and 162± 4.6 mPa respectively. Conclusions This simulation modeling could be used to compare results obtained from different perfusion bioreactor systems or different scaffold microarchitectures. It could allow specific shear stresses to be determined that optimize the distribution, proliferation or differentiation of seeded cells and the microarchitectures of the scaffold.