Williams Kenneth A, Saini Sunil, Wick Timothy M
School of Chemical Engineering and the Parker H Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Biotechnol Prog. 2002 Sep-Oct;18(5):951-63. doi: 10.1021/bp020087n.
Computational fluid dynamics (CFD) models to quantify momentum and mass transport under conditions of tissue growth will aid bioreactor design for development of tissue-engineered cartilage constructs. Fluent CFD models are used to calculate flow fields, shear stresses, and oxygen profiles around nonporous constructs simulating cartilage development in our concentric cylinder bioreactor. The shear stress distribution ranges from 1.5 to 12 dyn/cm(2) across the construct surfaces exposed to fluid flow and varies little with the relative number or placement of constructs in the bioreactor. Approximately 80% of the construct surface exposed to flow experiences shear stresses between 1.5 and 4 dyn/cm(2), validating the assumption that the concentric cylinder bioreactor provides a relatively homogeneous hydrodynamic environment for construct growth. Species mass transport modeling for oxygen demonstrates that fluid-phase oxygen transport to constructs is uniform. Some O(2) depletion near the down stream edge of constructs is noted with minimum pO(2) values near the constructs of 35 mmHg (23% O(2) saturation). These values are above oxygen concentrations in cartilage in vivo, suggesting that bioreactor oxygen concentrations likely do not affect chondrocyte growth. Scale-up studies demonstrate the utility and flexibility of CFD models to design and characterize bioreactors for growth of tissue-engineered cartilage.
用于量化组织生长条件下动量和质量传递的计算流体动力学（CFD）模型，将有助于设计用于组织工程软骨构建体开发的生物反应器。Fluent CFD模型用于计算在我们的同心圆柱生物反应器中模拟软骨发育的无孔构建体周围的流场、剪应力和氧分布。在暴露于流体流动的构建体表面上，剪应力分布范围为1.5至12达因/平方厘米，并且随着生物反应器中构建体的相对数量或位置变化很小。大约80%暴露于流动的构建体表面经历的剪应力在1.5至4达因/平方厘米之间，这验证了同心圆柱生物反应器为构建体生长提供相对均匀的流体动力学环境这一假设。氧的物质质量传递建模表明，流体相中的氧向构建体的传递是均匀的。在构建体下游边缘附近观察到一些氧消耗，构建体附近的最小pO₂值为35 mmHg（23%的氧饱和度）。这些值高于体内软骨中的氧浓度，表明生物反应器中的氧浓度可能不会影响软骨细胞的生长。放大研究证明了CFD模型在设计和表征用于组织工程软骨生长的生物反应器方面的实用性和灵活性。
