壳聚糖和pH对CHO细胞收获液澄清效率的影响

作者研究了壳聚糖和pH对中国仓鼠卵巢细胞（Chinese hamster ovary，CHO）培养液料液澄清过程的影响。初步探索了在CHO细胞收获液（pH 7.0）中添加0~0.10 g/dL壳聚糖对0.22 μm膜过滤通量的影响。结果显示，添加0.06 g/dL壳聚糖时膜过滤通量最大，达到8 266.22 L/（m2·h）。探索了pH值（5.0~7.0）对收获液澄清效率的影响，研究发现，不添加壳聚糖的情况下降低培养液pH值对膜过滤通量没有十分显著的提高。为更多地去除宿主细胞蛋白（Host Cell Protein，HCP）和残留DNA，作者研究了pH值与壳聚糖对膜过滤通量及残留杂质的交互影响。结果表明，pH为5.0壳聚糖质量浓度为0.06 g/dL时滤出液中残留DNA几乎完全去除，HCP含量降低50%以上，而抗体的回收率不受影响。
Chitosan is a natural，non-toxic and biodegradable flocculant. This study focused on determining and optimizing the clarification process efficiency in the presence of various concentrations （0~ 0.10 g/dL） of chitosan at different pH 5.0~7.0 for the harvested Chinese hamster ovary （CHO） cell culture fluid （HCCF）（pH 7.0）. Following HCCF was treated with 0.06 g/dL chitosan，the filtration flux was achieved up to 8 266.22 L/（m2·h） using 0.22 μm filter. In addition，the result showed that similar filtration flux for HCCF at different pH without chitosan addition whereas increasing filtration flux was achieved when HCCF pre-treated with chitosan at decreasing pH. To further improve this clarification process，the combined effect of various concentrations of chitosan at different pH on the filtration flux and the removal of process impurities including host cell proteins （HCP） and residual DNA in HCCF was evaluated. The result of a full factorial experiment including two factors and three levels （chitosan at 0.02，0.04，0.06% and pH at 5，6，7） showed that 90% antibody product yield with nearly complete removal of residual DNA and 50% more reduction of HCP were obtained when HCCF pre-treated with the optimal 0.06 g/dL chitosan at pH 5.0