The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
Biotechnol J. 2024 Mar;19(3):e2400063. doi: 10.1002/biot.202400063.
The effective design of perfusion cell culture is currently challenging regarding balancing the operating parameters associated with the hydrodynamic conditions due to increased system complexity. To address this issue, cellular responses of an industrial CHO cell line to different types of hydrodynamic stress in benchtop perfusion bioreactors originating from agitation, sparging, and hollow fibers (HF) in the cell retention devices were systematically investigated here with the analysis of cell lysis. It was found that cell lysis was very common and most associated with the sparging stress, followed by the HF and lastly the agitation, consequently heavily impacting the estimation of process descriptors related to biomass. The results indicated that the agitation stress led to a reduced cell growth with a shift toward a more productive phenotype, suggesting an energy redirection from biomass formation to product synthesis, whereas the sparging stress had a small impact on the intracellular metabolic flux distribution but increased the cell death rate drastically. For HF stress, a similar cell maintenance profile was found as the sparging while the activity of glycolysis and the TCA cycle was significantly impeded, potentially leading to the lack of energy and thus a substantial decrease in cell-specific productivity. Moreover, a novel concept of volume average shear stress was developed to further understand the relations of different types of stress and the observed responses for an improved insight for the perfusion cell culture.
目前，由于系统复杂性的增加，灌流细胞培养的有效设计在平衡与流体动力条件相关的操作参数方面具有挑战性。为了解决这个问题，本研究系统地研究了工业 CHO 细胞系在台式灌流生物反应器中对不同类型的流体动力应激的细胞反应，这些应激源来自于搅拌、通气和细胞截留装置中的中空纤维（HF），并通过细胞裂解分析进行了研究。结果发现，细胞裂解非常普遍，与通气应激最相关，其次是 HF，最后是搅拌，这对与生物量相关的过程描述符的估计产生了重大影响。结果表明，搅拌应激导致细胞生长减少，向更具生产力的表型转变，这表明能量从生物量形成转向产物合成的重新分配，而通气应激对细胞内代谢通量分布的影响较小，但会大大增加细胞死亡率。对于 HF 应激，发现与通气相似的细胞维持谱，而糖酵解和 TCA 循环的活性受到明显抑制，可能导致能量缺乏，从而导致细胞特异性生产率大幅下降。此外，还开发了一种新的体积平均剪切应力概念，以进一步了解不同类型的应激之间的关系和观察到的反应，从而为灌流细胞培养提供更好的见解。
