Bayer Benjamin, Duerkop Mark, Striedner Gerald, Sissolak Bernhard
Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria.
Novasign GmbH, Vienna, Austria.
Front Bioeng Biotechnol. 2021 Dec 23;9:740215. doi: 10.3389/fbioe.2021.740215. eCollection 2021.
Reliable process development is accompanied by intense experimental effort. The utilization of an intensified design of experiments (iDoE) (intra-experimental critical process parameter (CPP) shifts combined) with hybrid modeling potentially reduces process development burden. The iDoE can provide more process response information in less overall process time, whereas hybrid modeling serves as a commodity to describe this behavior the best way. Therefore, a combination of both approaches appears beneficial for faster design screening and is especially of interest at larger scales where the costs per experiment rise significantly. Ideally, profound process knowledge is gathered at a small scale and only complemented with few validation experiments on a larger scale, saving valuable resources. In this work, the transferability of hybrid modeling for Chinese hamster ovary cell bioprocess development along process scales was investigated. A two-dimensional DoE was fully characterized in shake flask duplicates (300 ml), containing three different levels for the cultivation temperature and the glucose concentration in the feed. Based on these data, a hybrid model was developed, and its performance was assessed by estimating the viable cell concentration and product titer in 15 L bioprocesses with the same DoE settings. To challenge the modeling approach, 15 L bioprocesses also comprised iDoE runs with intra-experimental CPP shifts, impacting specific cell rates such as growth, consumption, and formation. Subsequently, the applicability of the iDoE cultivations to estimate static cultivations was also investigated. The shaker-scale hybrid model proved suitable for application to a 15 L scale (1:50), estimating the viable cell concentration and the product titer with an NRMSE of 10.92% and 17.79%, respectively. Additionally, the iDoE hybrid model performed comparably, displaying NRMSE values of 13.75% and 21.13%. The low errors when transferring the models from shaker to reactor and between the DoE and the iDoE approach highlight the suitability of hybrid modeling for mammalian cell culture bioprocess development and the potential of iDoE to accelerate process characterization and to improve process understanding.
可靠的工艺开发伴随着大量的实验工作。将强化实验设计（iDoE）（实验内关键工艺参数（CPP）转移相结合）与混合建模相结合，有可能减轻工艺开发负担。iDoE可以在更短的总工艺时间内提供更多的工艺响应信息，而混合建模则是描述这种行为的最佳方式。因此，将这两种方法结合起来似乎有利于更快地进行设计筛选，在每个实验成本显著增加的更大规模实验中尤其如此。理想情况下，在小规模实验中收集深入的工艺知识，仅通过少量大规模验证实验进行补充，从而节省宝贵的资源。在这项工作中，研究了混合建模在中国仓鼠卵巢细胞生物工艺开发中跨工艺规模的可转移性。在摇瓶复制品（300毫升）中对二维实验设计进行了全面表征，其中包含培养温度和进料中葡萄糖浓度的三个不同水平。基于这些数据，开发了一个混合模型，并通过在具有相同实验设计设置的15升生物工艺中估计活细胞浓度和产物滴度来评估其性能。为了挑战建模方法，15升生物工艺还包括具有实验内CPP转移的iDoE运行，影响特定的细胞速率，如生长、消耗和形成。随后，还研究了iDoE培养用于估计静态培养的适用性。摇床规模的混合模型被证明适用于15升规模（1:50），估计活细胞浓度和产物滴度的归一化均方根误差（NRMSE）分别为10.92%和17.79%。此外，iDoE混合模型表现相当，NRMSE值分别为13.75%和21.13%。将模型从摇床转移到反应器以及在实验设计和iDoE方法之间转移时的低误差，突出了混合建模在哺乳动物细胞培养生物工艺开发中的适用性，以及iDoE在加速工艺表征和提高工艺理解方面的潜力。
