Mass-scale Purification And Quality Control Of A Single-chain Chimeric Anti-ErbB2 Antibody

The ErbB2 is a transmembrane glycoprotein with intrinsic tyrosine-kinase activities and belongs to epidermal growth factor receptor family. It overexpressed in several malignant human tumors like breast cancer. So using monoclonal antibodies to target overexpressed ErbB2 cancer for clinical therapy became a new strategy and powerful tool. Our libratory constructed single-chain Chimeric Anti-ErbB2 Antibody chA21 by assembling a single-chain Fv antibody and a human IgG1 Fc fragment. In my dissertation, we developed the purification procedure of chA21, identified the chA21 product and researched the new purification strategy, mainly including three chapters:1,chA21 from engineered CHO cells were cultured in the packed bed bioreactor. To establish mass-scale purification technology, culture supernatant was collected and purified in a sequence of downstream processing steps, namely, affinity chromatography, desalting, ion exchange chromatography and molecular sieve chromatography. By the developed mass-scale procedure, formed aggregates could be removed effetely; endotoxins and residual DNA were also extracted. 10L~20L of culture supernatant could be treated in a single operation. The purify rate reached more than 98% and the total recovery rate was over 50%.2,chA21 product was all analyzed according to the national standard of biologic product. The items included content, purity, foreigh material, contaminant, physoci-chemical property and biology activity. The results indicated that chA21 product was in line with the standard of injection medicine. So the purify rate of the produce technics was high and quality inspection methods were stability and reliable, which could be fit for in large-scale production of chA21.3,Researched the new purification strategy through the other chromatograghy.The study on purification and stability of chA21 may be the foundation for drug application.