Division of Biomechanics and Engineering Design, Katholieke Universiteit Leuven, Belgium.
Tissue Eng Part C Methods. 2011 Jun;17(6):619-30. doi: 10.1089/ten.TEC.2010.0647. Epub 2011 Mar 23.
Inhomogeneous and uncontrolled cellular and tissue responses in bone tissue engineering constructs, as a result of heterogeneous oxygen delivery throughout the scaffold volume, is one of the hurdles hampering clinical transfer of cell-scaffold combinations. This study presents an accurate and computationally efficient one-dimensional model that predicts the oxygen distribution for a regular cell-seeded scaffold in a perfusion bioreactor and the maximum (i.e., critical) scaffold length (L(max)) as a function of given oxygen constraints. After validation against computational fluid dynamics models, the one-dimensional model was applied to calculate L(max) in the perfusion direction, to ensure appropriate oxygen levels throughout the bone tissue engineering construct during in vitro culture. Both cell-related (cell density and oxygen consumption rate) and bioreactor-related (oxygen constraints and flow rate) culture parameters were varied. Results demonstrated the substantial influence of the culture parameters on L(max). In conclusion, the presented computational tool was able to predict oxygen distribution and maximum scaffold length for regular cell-seeded scaffold. It can be used to design perfusion experiments wherein quantitative knowledge on both oxygen and flow characteristics is needed.
在骨组织工程构建体中，由于整个支架体积内供氧不均匀和不可控，导致细胞和组织反应不均匀，这是阻碍细胞-支架组合临床转化的障碍之一。本研究提出了一种准确且计算效率高的一维模型，可预测在灌注生物反应器中常规细胞接种支架的氧分布，以及最大（即临界）支架长度（L(max)）作为给定氧约束的函数。在与计算流体动力学模型验证后，将一维模型应用于计算灌注方向上的 L(max)，以确保在体外培养过程中整个骨组织工程构建体中的适当氧气水平。改变了与细胞相关的（细胞密度和耗氧率）和与生物反应器相关的（氧约束和流速）培养参数。结果表明，培养参数对 L(max)有很大影响。总之，所提出的计算工具能够预测常规细胞接种支架的氧分布和最大支架长度。它可用于设计需要定量了解氧气和流动特性的灌注实验。
