The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, London, UK.
Biopharmaceutical Development: Bioprocess Technologies and Engineering, AstraZeneca, Gaithersburg, USA.
Biotechnol Prog. 2022 Jul;38(4):e3264. doi: 10.1002/btpr.3264. Epub 2022 May 7.
Understanding the impact of spatial heterogeneities that are known to occur in large-scale cell culture bioreactors remains a significant challenge. This work presents a novel methodology for mimicking the effects of pH and dissolved oxygen heterogeneities on Chinese hamster ovary (CHO) cell culture performance and antibody quality characteristics, using an automated miniature bioreactor system. Cultures of 4 different cell lines, expressing 3 IgG molecules and one fusion protein, were exposed to repeated pH and dissolved oxygen tension (DOT) fluctuations between pH 7.0-7.5 and DOT 10%-30%, respectively, for durations of 15, 30, and 60 min. Fluctuations in pH had a minimal impact on growth, productivity, and product quality although some changes in lactate metabolism were observed. DOT fluctuations were found to have a more significant impact; a 35% decrease in cell growth and product titre was observed in the fastest growing cell line tested, while all cell lines exhibited a significant increase in lactate accumulation. Product quality analysis yielded varied results; two cell lines showed an increase in the G0F glycan and decrease in G1F, G2F, and Man5; however, another line showed the opposite trend. The study suggests that the response of CHO cells to the effects of fluctuating culture conditions is cell line specific and that higher growing cell lines are most impacted. The miniature bioreactor system described in this work therefore provides a platform for use during early stage cell culture process development to identify cell lines that may be adversely impacted by the pH and DOT heterogeneities encountered on scale-up. This experimental data can be combined with computational modeling approaches to predict overall cell culture performance in large-scale bioreactors.
理解在大规模细胞培养生物反应器中已知存在的空间异质性的影响仍然是一个重大挑战。本工作提出了一种新的方法，使用自动化微型生物反应器系统模拟 pH 和溶解氧异质性对中国仓鼠卵巢 (CHO) 细胞培养性能和抗体质量特性的影响。4 种不同细胞系的培养物分别表达 3 种 IgG 分子和 1 种融合蛋白，分别暴露于 pH 7.0-7.5 和溶解氧张力 (DOT) 10%-30%之间的重复 pH 和 DOT 波动中，持续时间分别为 15、30 和 60 min。尽管观察到一些乳酸代谢的变化，但 pH 波动对生长、生产力和产品质量的影响最小。DOT 波动的影响更大；在测试的生长最快的细胞系中，细胞生长和产物滴度下降了 35%，而所有细胞系的乳酸积累都显著增加。产品质量分析得出了不同的结果；两种细胞系的 G0F 聚糖增加，G1F、G2F 和 Man5 减少；然而，另一条线则呈现相反的趋势。该研究表明，CHO 细胞对波动培养条件影响的反应是细胞系特异性的，生长较快的细胞系受到的影响最大。本工作中描述的微型生物反应器系统因此提供了一个平台，可用于早期细胞培养工艺开发过程中，以识别可能受到放大过程中遇到的 pH 和 DOT 异质性不利影响的细胞系。该实验数据可以与计算建模方法相结合，以预测大规模生物反应器中的整体细胞培养性能。
