Advancing continuous encapsulation and purification of mRNA vaccines and therapeutics
Ehsan Nourafkan, Zidi Yang, Mabrouka Maamra, Zoltán Kis
Abstract
The messenger RNA (mRNA) platform technology is advancing the deployment of vaccines and therapeutics to combat various diseases. The COVID-19 pandemic highlighted the urgent need for large-scale mRNA vaccine production, exposing supply constraints and driving demand for more cost-effective and scalable manufacturing solutions. To address these challenges, integrated and continuous mRNA manufacturing processes provide significant advantages over traditional batch methods, including increased efficiency, reduced labor requirements, a smaller manufacturing footprint, and faster production. Here, we present the first continuous process integrating: 1) continuous flow encapsulation of mRNA into lipid nanoparticles (LNPs), 2) real-time in-line particle size and polydispersity index (PDI) monitoring using spatially-resolved dynamic light scattering, 3) single-pass tangential flow filtration (SP-TFF) purification of mRNA-LNPs. The continuously produced and SP-TFF purified mRNA-LNP critical quality attributes are: 95.5 ± 4 % encapsulation efficiency, 105±6 nm average particle size, 0.1 ± 0.02 PDI, 0.003 % residual ethanol content, 0.4 ± 0.05 % fraction of unloaded LNPs, 86.2 ± 3 % mRNA integrity, and the final pH of 7. During the TFF purification, an increase in average mRNA-LNP size and formation of bleb compartments on the particle's surface was also observed. Additionally, a 90 % recovery of mRNA-LNPs was achieved using regenerated cellulose (RC) membrane SP-TFF with an overall concentration factor of 10X. This study lays the foundations for faster and more efficient manufacturing of high-quality mRNA vaccines and therapeutics.