Tissue engineering is a promising option for cartilage repair. However, several hurdles still need to be overcome to develop functional tissue constructs suitable for implantation. One of the most common challenges is the general low capacity of chondrocytes to synthesize cartilage‐specific extracellular matrix (ECM). While different approaches have been explored to improve the biosynthetic response of chondrocytes, several studies have demonstrated that the nutritional environment (e.g., glucose concentration and media volume) can have a profound effect on ECM synthesis. Thus, the purpose of this study was to optimize the formulation of cell culture media to upregulate the accumulation of cartilaginous ECM constituents (i.e., proteoglycans and collagen) by chondrocytes in 3D culture. Using response surface methodology, four different media factors (basal media, media volume, glucose, and glutamine) were first screened to determine optimal media formulations. Constructs were then cultured under candidate optimal media formulations for 4 weeks and analyzed for their biochemical and structural properties. Interestingly, the maximal accumulation of proteoglycans and collagen appeared to be elicited by different media formulations. Most notably, proteoglycan accumulation was favored by high volume, low glucose‐containing DMEM/F12 (1:1) media whereas collagen accumulation was favored by high volume, high glucose‐containing F12 media. While high glutamine‐containing media elicited increased DNA content, glutamine concentration had no apparent effect on ECM accumulation. Therefore, optimizing the nutritional environment during chondrocyte culture appears to be a promising, straight‐forward approach to improve cartilaginous tissue formation. Future work will investigate the combined effects of the nutritional environment and external stimuli.

中文翻译：

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优化培养基以促进组织工程软骨的生长。

组织工程是软骨修复的一个有前途的选择。然而，仍然需要克服几个障碍来开发适合植入的功能性组织结构。最常见的挑战之一是软骨细胞合成软骨特异性细胞外基质 (ECM) 的能力普遍较低。虽然已经探索了不同的方法来改善软骨细胞的生物合成反应，但一些研究表明，营养环境（例如，葡萄糖浓度和培养基体积）会对 ECM 合成产生深远的影响。因此，本研究的目的是优化细胞培养基的配方，以上调软骨细胞在 3D 培养中的软骨 ECM 成分（即蛋白多糖和胶原蛋白）的积累。使用响应面方法，首先筛选四种不同的培养基因素（基础培养基、培养基体积、葡萄糖和谷氨酰胺）以确定最佳培养基配方。然后将构建体在候选最佳培养基配方下培养 4 周，并分析其生化和结构特性。有趣的是，蛋白聚糖和胶原蛋白的最大积累似乎是由不同的培养基配方引起的。最值得注意的是，高容量、低葡萄糖的 DMEM/F12 (1:1) 培养基有利于蛋白多糖的积累，而高容量、高葡萄糖的 F12 培养基有利于胶原蛋白的积累。虽然高谷氨酰胺培养基引起 DNA 含量增加，但谷氨酰胺浓度对 ECM 积累没有明显影响。所以，在软骨细胞培养过程中优化营养环境似乎是改善软骨组织形成的一种有前途的、直接的方法。未来的工作将调查营养环境和外部刺激的综合影响。