Gramer MJ, Poeschl DM
Cellex Biosciences, Inc., 8500 Evergreen Boulevard, Coon Rapids, Minnesota 55433, USA.
Biotechnol Prog. 1998 Mar;14(2):203-9. doi: 10.1021/bp9800081.
Fundamental research of factors affecting cell growth in hollow-fiber bioreactors is hindered by the lack of an efficient screening tool. To address this issue, a hollow-fiber micro-bioreactor has been developed. Hollow fibers with 10 kDa molecular weight cutoffs are housed within a piece of silicone tubing. Cells are inoculated within the hollow fibers which provides a 0.2-mL culture volume. The space between the fibers and silicone tubing (5 or 16 mL) is used as a medium reservoir sufficient to feed the cells for at least 24 h. Oxygenation is provided directly through the silicone tubing so that a pump for medium recirculation is not required. As a result, many conditions can be tested simultaneously in a single incubator. Three days after inoculation at 5 x 10(6) cells/mL in the micro-bioreactor, the rho 1D4 murine hybridoma cell line reached 2.8 x 10(7) cells/mL with an antibody concentration of 0.17 mg/mL. When inoculated at 5 x 10(7) cells/mL, the cell concentration reached 1.8 x 10(8)/mL after 3 days with an antibody concentration of 1.0 mg/mL. Results from a series of experiments with the micro-bioreactor suggested that the initial growth phase of this cell line in a hollow-fiber system is dependent on the serum concentration in the medium reservoir. This prediction was tested by simultaneously inoculating two production-scale hollow-fiber bioreactor systems. The cell side of the membrane for each bioreactor contained 10% serum, but serum was added to the reservoir side of only one of the bioreactors. The cells with only basal medium in the reservoir died after a few days, while the cells with 10% serum in the medium reservoir grew rapidly. These results demonstrate that the micro-bioreactor developed here can support good cell growth and that it can be used as a research tool to predict the performance of large-scale hollow-fiber systems.
缺乏高效的筛选工具阻碍了对中空纤维生物反应器中影响细胞生长因素的基础研究。为了解决这个问题，已经开发出一种中空纤维微型生物反应器。截留分子量为10 kDa的中空纤维被置于一段硅胶管内。细胞接种于中空纤维内，其提供0.2 mL的培养体积。纤维与硅胶管之间的空间（5或16 mL）用作培养基储库，足以维持细胞至少24小时的营养供给。通过硅胶管直接进行氧合，因此不需要用于培养基再循环的泵。结果，在单个培养箱中可以同时测试许多条件。在微型生物反应器中以5×10⁶个细胞/mL接种三天后，rho 1D4鼠杂交瘤细胞系达到2.8×10⁷个细胞/mL，抗体浓度为0.17 mg/mL。当以5×10⁷个细胞/mL接种时，三天后细胞浓度达到1.8×10⁸/mL，抗体浓度为1.0 mg/mL。一系列使用微型生物反应器的实验结果表明，该细胞系在中空纤维系统中的初始生长阶段取决于培养基储库中的血清浓度。通过同时接种两个生产规模的中空纤维生物反应器系统对这一预测进行了测试。每个生物反应器膜的细胞侧含有10%的血清，但仅向其中一个生物反应器的储库侧添加血清。储库中仅含基础培养基的细胞几天后死亡，而培养基储库中含10%血清的细胞生长迅速。这些结果表明，此处开发的微型生物反应器能够支持良好的细胞生长，并且可以用作预测大规模中空纤维系统性能的研究工具。
