Abstract:

The main component of the Center for Genetic Engineering and Biotechnology (CIGB) candidate vaccine against Hepatitis C virus (HCV) is the pIDKE2 plasmid.The current designed downstream process for the production of pIDKE2 fulfils all regulatory requirements and renders the required quantities of pharmaceutical-grade plasmid DNA (pDNA) with 95% purity.The advantages of this procedure include high plasmid purity and the elimination of undesirable additives,such as toxic organic extractants and animal-derived enzymes.However,yields and consequently the productivity of the process are low.Previous work demonstrated that the most critical step of the process is the reverse phase chromatography,where conventional porous particle resins are used.Therefore,to increase the process productivity,alternative technologies such as membranes and chromatographic monoliths were tested as alternative options for this critical step.Here,a comparison between the behaviors of CIM^® C4-HLD and Sartobind phenyl matrices was performed.To obtain higher productivities and purities,the dynamic binding capacities and selectivities were evaluated.The results showed that both matrices had a similar capacity for pIDKE2 plasmid,but the separation of pDNA isoforms using CIM technology was much better than that with Sartobind.Additionally,the optimal conditions for loading plasmid DNA on a CIM^® C4-HLD 800-mL monolithic column in a real production process were determined.These optimizations will allow production levels to satisfy the high plasmid consumption demanded by clinical trials.

Key words: breakthrough, downstream processing, membrane, monolith, open circular (OC) plasmid, plasmid DNA (pDNA), supercoiled (SC) plasmid