Process Research and Development, Merck & Co., Inc., Kenilworth, New Jersey.
Biotechnol Bioeng. 2020 Nov;117(11):3336-3344. doi: 10.1002/bit.27504. Epub 2020 Jul 30.
Although several compelling benefits for bioprocess intensification have been reported, the need for a streamlined integration of perfusion cultures with capture chromatography still remains unmet. Here, a robust solution is established by conducting tangential flow filtration-based perfusion with a wide-surface pore microfiltration membrane. The resulting integrated continuous bioprocess demonstrated negligible retention of antibody, DNA, and host cell proteins in the bioreactor with average sieving coefficients of 98 ± 1%, 124 ± 28%, and 109 ± 27%, respectively. Further discussion regarding the potential membrane fouling mechanisms is also provided by comparing two membranes with different surface pore structures and the same hollow fiber length, total membrane area, and chemistry. A cake-growth profile is reported for the narrower surface pore, 0.65-µm nominal retention perfusion membrane with final antibody sieving coefficients ≤70%. Whereas the sieving coefficient remained ≥85% during 40 culture days for the wide-surface pore, 0.2-µm nominal retention rating membrane. The wide-surface pore structure, confirmed by scanning electron microscopy imaging, minimizes the formation of biomass deposits on the membrane surface and drastically improves product sieving. This study not only offers a robust alternative for integrated continuous bioprocess by eliminating additional filtration steps while overcoming sieving decay, but also provides insight into membranes' fouling mechanism.
尽管已有多项引人注目的生物工艺强化优势被报道,但仍需要简化灌流培养与捕获色谱的集成。在这里,通过使用具有宽表面积孔的微滤膜进行切向流过滤式灌流,建立了一种稳健的解决方案。所得到的集成式连续生物工艺在生物反应器中对抗体、DNA 和宿主细胞蛋白的保留率可忽略不计,平均筛分系数分别为 98±1%、124±28%和 109±27%。通过比较两种具有不同表面孔结构但具有相同中空纤维长度、总膜面积和化学性质的膜,进一步讨论了潜在的膜污染机制。对于较窄的表面孔,0.65-µm 名义保留灌流膜,报道了一个滤饼生长曲线,其最终抗体筛分系数≤70%。而对于宽表面积孔、0.2-µm 名义保留等级膜,筛分系数在 40 天的培养过程中保持≥85%。通过扫描电子显微镜成像证实的宽表面积孔结构最大限度地减少了在膜表面上生物质沉积物的形成,并极大地提高了产物的筛分。本研究不仅通过消除额外的过滤步骤并克服筛分衰减提供了一种稳健的集成连续生物工艺替代方案,还深入了解了膜的污染机制。