High-pressure refolding of human vascular endothelial growth factor (VEGF) recombinantly expressed in bacterial inclusion bodies: refolding optimization, and feasibility assessment

High-pressure has been established as an effective technique for refolding proteins at high concentrations. In this study, high hydrostatic pressure (1-3 kbar) was utilized to refold a homodimeric protein from inclusion bodies and the process was evaluated for large-scale manufacturing feasibility. This research focused on increasing protein concentration while maximizing yield and product quality. Refolding yields of 29-42% were achieved in the absence of urea at 2 kbar and at a protein concentration of 6 g/L. Optimization of the refolding buffer composition via multivariate design of experiments and other process parameters such as refolding pressure, gas sparging, and time under pressure are discussed. Although high-pressure refolding can be considered a viable technology for manufacturing if the gains are clearly identified, in this particular case, the benefits that the high-pressure technology offers do not compensate for the drawbacks of implementing new equipment in an existing facility, and unknown impact of scale-up for this molecule.