利用实验设计筛选并优化SARS-CoV-2单抗F61亲和层析阶段工艺参数

Screening and optimization of process parameters of SARS-CoV-2 monoclonal antibody F61 in affinity chromatography stage using design of experiment

目的利用实验设计(Design of Experiment,DoE)筛选及优化实验对SARS-CoV-2单抗F61亲和层析工艺参数进行筛选及优化,获得最佳工艺条件。方法选择8个可能在亲和层析中影响实验响应结果的工艺参数并制定其水平范围,利用DoE筛选实验对选择的工艺参数进行8因子2水平筛选实验,通过检测响应值,用统计学软件拟合数学模型,经帕累托图分析获得3个显著影响关键质量属性的关键工艺参数(P<0.05),再选择DoE响应曲面法对关键工艺参数进行优化实验。首先完成全析因实验设计部分,检测响应结果拟合数学模型,分析弯曲项P值判断显著因子的工艺参数范围处于最佳范围内(弯曲P<0.05)后,再根据实验的序贯性补齐中心复合表面设计(central composite face-centered design,CCF)实验,通过检测响应结果拟合响应曲面模型,获得工艺最佳条件范围,最终通过重复试验验证最佳参数值的稳定性。结果在筛选实验中获得在亲和层析阶段影响F61的显著因子为洗脱缓冲液pH、洗脱缓冲液盐浓度、中间淋洗缓冲液盐浓度、平衡缓冲液盐浓度。通过CCF实验最终获得亲和层析中关键工艺参数的最佳条件,当洗脱缓冲液pH为3.2、洗脱缓冲液盐浓度为0.07 mol/L NaCl、中间淋洗缓冲液盐浓度为0.31 mol/L NaCl,F61在亲和层析阶段收率达95.25%,宿主细胞蛋白(host cell protein,HCP)残留量为97.33 ppm,样品单体纯度达98.51%。结论用不同类型DoE方法进行了F61亲和层析阶段工艺参数的筛选和优化,获得了最佳工艺条件,为F61纯化工艺的建立奠定了基础。

Objective To select and optimize the process parameters of SARS-CoV-2 F61 affinity chromatography by the screening and optimization experiment of Design of Experiment(DoE),in order to obtain the optimal process conditions.Methods Eight process parameters that may affect the experimental response results in affinity chromatography were selected and their level ranges were determined.DoE screening test was used to perform 8 factor 2 level screening tests on the selected process parameters.The response values were detected and the mathematical model was fitted by statistical software.Three key process parameters significantly affecting the key quality attributes were obtained by Pareto diagram analysis(P<0.05).Then DoE response surface method(RSM)was selected to optimize the key process parameters.First,the full factorial experiment design was completed,the response results were detected to fit the mathematical model,and the bending term P value was analyzed to judge the range of significant factors in the optimal range(bending P<0.05),then according to the sequential complement of the central composite face-centered design(CCF)experiment,through the detection of the response results to fit the response surface model,the range of optimal conditions was obtained,and the stability of the optimal parameters was finally verified by repeated experiments.Results In the screening experiment,it was found that the significant factors affecting F61 in the affinity chromatography stage were elution buffer pH,elution buffer salt concentration,leaching buffer salt concentration and equilibrium buffer salt concentration.The optimal conditions of key process parameters in affinity chromatography were obtained by CCF.When the pH of elution buffer was 3.2,the elution buffer salt concentration was 0.07 mol/L NaCl,and the leaching buffer salt concentration was 0.31 mol/L NaCl,the yield of F61 reached 95.25%,the residual amount of host cell protein(HCP)was 97.33 ppm,and the monomer purity of the sample was98.51%at the affinity chromatography stage.Conclusion Different types of DoE methods were used to screen and optimize the process parameters of F61 affinity chromatography stage,and the optimal process conditions were obtained,which lays a foundation for the esta-blishment of F61 purification process.