A key step in the tissue engineering of articular cartilage is the chondrogenic differentiation of mesenchymal stem cells (MSCs) into chondrocytes (native cartilage cells). Chondrogenesis is regulated by transforming growth factor-β (TGF-β), a short-lived cytokine whose effect is prolonged by storage in the extracellular matrix. Tissue engineering applications aim to maximise the yield of differentiated MSCs. Recent experiments involve seeding a hydrogel construct with a layer of MSCs lying below a layer of chondrocytes, stimulating the seeded cells in the construct from above with exogenous TGF-β and then culturing it in vitro. To investigate the efficacy of this strategy, we develop a mathematical model to describe the interactions between MSCs, chondrocytes and TGF-β. Using this model, we investigate the effect of varying the initial concentration of TGF-β, the initial densities of the MSCs and chondrocytes, and the relative depths of the two layers on the long-time composition of the tissue construct.

中文翻译：

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确定关节软骨组织工程的软骨形成策略。

关节软骨组织工程的关键步骤是将间充质干细胞（MSC）分化为软骨细胞（天然软骨细胞）。软骨形成受转化生长因子-β (TGF-β) 的调节，转化生长因子-β 是一种短寿命的细胞因子，其作用通过储存在细胞外基质中而得以延长。组织工程应用旨在最大限度地提高分化间充质干细胞的产量。最近的实验涉及在软骨细胞层下方接种一层 MSC 的水凝胶结构，用外源 TGF-β 从上方刺激结构中的接种细胞，然后在体外培养。为了研究该策略的功效，我们开发了一个数学模型来描述 MSC、软骨细胞和 TGF-β 之间的相互作用。使用该模型，我们研究了改变 TGF-β 的初始浓度、MSC 和软骨细胞的初始密度以及两层的相对深度对组织构建体的长期组成的影响。