Oxygen gradients in tissue-engineered PEGT/PBT cartilaginous constructs: Measurement and modeling
Oxygen gradients in tissue-engineered PEGT/PBT cartilaginous constructs: Measurement and modeling
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DOI：
10.1002/bit.20038
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发表时间：
2004-04-05
影响因子：
3.8
通讯作者：
Riesle, J
中科院分区：
文献类型：
--
作者：
Malda, J;Rouwkema, J;Riesle, J
三维组织工程（TE）软骨聚合物结构内的氧气供应主要是通过扩散。细胞的氧消耗导致氧浓度的梯度。本研究的目的是，首先，以确定TE内的梯度：软骨聚合物结构，其次，预测在体外培养过程中的配置文件。玻璃微电极系统进行了调整，并用于穿透软骨和TE软骨结构，产生可重复的测量与高空间分辨率。在体外培养Carbohydrate聚合物构建体长达41天。在这些结构的中心内测量低至2 - 5%的氧浓度。在体外培养开始时，TE构建体中的氧梯度比天然组织更陡。然而，在培养过程中，氧浓度接近在天然组织中测量的值。开发了一种数学模型，该模型产生软骨外植体和TE构建体内的氧分布。评估模型输入参数，包括软骨的扩散系数（2.2 x 10（-9））+（0.4 x 10（-9）m（2）s（-1））、70%水的扩散系数和结构的扩散系数（3.8 x 10（-10）m（2）s（-1））。该模型证实，培养27天的聚合物结构中的软骨细胞具有较低的氧气需求（0.8 × 10（-19）mol m（-3）s（-1）），甚至低于天然软骨中的软骨细胞。测量和预测局部氧张力的能力提供了新的机会，以获得更多的了解氧张力和软骨形成之间的关系。(C)2004 Wiley Periodicals，Inc.
The supply of oxygen within three-dimensional tissue-engineered (TE) cartilage polymer constructs is mainly by diffusion. Oxygen consumption by cells results in gradients in the oxygen concentration. The aims of this study were, firstly, to identify the gradients within TE: cartilage polymer constructs and, secondly, to predict the profiles during in vitro culture. A glass microelectrode system was adapted and used to penetrate cartilage and TE cartilaginous constructs, yielding reproducible measurements with high spatial resolution. Cartilage polymer constructs were cultured for up to 41 days in vitro. Oxygen concentrations, as low as 2 - 5%, were measured within the center of these constructs. At the beginning of in vitro culture, the oxygen gradients were steeper in TE constructs in comparison to native tissue. Nevertheless, during the course of culture, oxygen concentrations approached the values measured in native tissue. A mathematical model was developed which yields oxygen profiles within cartilage explants and TE constructs. Model input parameters were assessed, including the diffusion coefficient of cartilage (2.2 x 10(-9)) + (0.4 x 10(-9) m(2) s(-1)), 70% of the diffusion coefficient of water and the diffusion coefficient of constructs (3.8 x 10(-10) m(2) s(-1)). The model confirmed that chondrocytes in polymer constructs cultured for 27 days have low oxygen requirements (0.8 x 10(-19) mol m(-3) s(-1)), even lower than chondrocytes in native cartilage. The ability to measure and predict local oxygen tensions offers new opportunities to obtain more insight in the relation between oxygen tension and chondrogenesis. (C) 2004 Wiley Periodicals, Inc.