SENSITIVITY ANALYSIS FOR MODEL COMPARISON AND SELECTION IN TISSUE ENGINEERING

ABSTRACT Computational modeling has been proven to be very useful in tissue engineering over the past years. Because the model is a simplification of the experimental system, the processes accounted for in the model should be analyzed carefully. However, new and complex models are usually proposed without a clear comparison with the basic ones. In this study, the contribution of oxygen to Contois growth kinetics and porosity variation with time due to polymer degradation was evaluated through a sensitivity analysis. The effect of initial glucose concentration, porosity and thickness of the scaffold on the cell volume fraction and substrate concentration was analyzed for three models. Even with the inclusion of oxygen concentration in the model, the output variables are more affected by the initial cell number, while the model with variable porosity is quite robust to variations in the input variables.

摘要 近年来，计算建模已被证实于组织工程领域极具应用价值。由于模型是对实验系统的简化，需对模型所涵盖的各类过程进行审慎分析。然而，新型复杂模型的提出通常未与基础模型开展明确对比。本研究通过敏感性分析，评估了氧气对康托伊生长动力学（Contois growth kinetics）的贡献，以及聚合物降解引发的孔隙率随时间的变化规律。针对三类模型，本研究分析了初始葡萄糖浓度、支架孔隙率与支架厚度对细胞体积分数及底物浓度的影响。即便模型纳入了氧气浓度参数，输出变量仍更多受初始细胞数影响；而具备可变孔隙率的模型对输入变量的变化具有较强鲁棒性。