Downstream processing development of enveloped viruses for clinical applications: innovative tools for rational process optimization

Dissertation presented to obtain a Ph.D. degree in Engineering and Technology Sciences, Biotechnology at the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa

Viral vectors and virus-like particles hold a tremendous potential in various clinical applications in the areas of gene therapy and/or vaccination, drawing the attention of biotechnology and pharmaceutical companies. The majority of these products are manufactured in animal cell cultures, inherently making the process costly. A great deal of effort is taking place to generate optimized biological and engineering strategies to find scalable and cost-effective processes, easily transferable to cGMP facilities. However, the implementation of robust downstream processes generating this type of biopharmaceuticals in the amounts required for pre-clinical and clinical trials is still lacking and lagging. By including a labile lipid membrane layer harboring glycoproteins (often critical for infection) over the viral capsid, enveloped viruses bring extra challenges in terms of their bioprocessing particularly downstream. The work developed during this thesis aimed at improving the state-of-the-art purification processes for these types of viral particles. The rationale was to integrate process understanding with product characterization, still scarce in such biological systems.(...)