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Recent advances in the use of viral vectors for gene therapy has created a need for efficient downstream processing of these novel therapeutics. Single-pass tangential flow filtration (SPTFF) can potentially improve final product quality via reductions in shear, and it can increase manufacturing productivity via simple implementation into continuous/intensified processes. This study investigated the impact of variations in pressure and flow rate along the length of the membrane on overall SPTFF performance. Constant-flux filtration experiments at feed fluxes from 14 to 420 L/m2/h (Reynolds numbers <20) were performed using Pellicon® 3 TFF cassettes with fluorescent nanoparticles as model viral vectors. The location of nanoparticle accumulation shifted towards the filter outlet at high conversion and was also a function of the permeate flow configuration. These phenomena were explained using a newly developed concentration polarization model that predicts the distribution in local wall concentration over the length of the membrane. The model accurately captured the observed nanoparticle accumulation trends, including the effects of the permeate flow profile (co-current, divergent, or convergent flow) on nanoparticle accumulation within the SPTFF module. Nanoparticle accumulation at moderate conversion was more uniform using convergent flow, but nanoparticle accumulation at 80 % conversion (5x concentration factor) can be minimized using a divergent flow configuration. The local wall concentration model was also used to evaluate the critical flux by assuming that fouling occurs when the nanoparticle concentration at any point along the membrane surface exceeds 15 % by volume. These results provide important insights for the design and operation of SPTFF technology for inline concentration of viral vectors.
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Inline Protein Concentration by Vibratory Single Pass Tangential Flow Filtration
ABSTRACT Single Pass Tangential Flow Filtration (SPTFF) is increasingly used for inline concentration and final formulation in intensified/continuous processes for monoclonal antibody products. However, these modules typically operate at low feed flux, requiring significant membrane area and often complex internal staging to achieve the desired concentration factor. In this study, a vibration‐assisted SPTFF system was used for inline concentration of soluble protein. The maximum sustainable flux and concentration factor were evaluated under vibratory and non‐vibratory conditions using flux‐stepping experiments. SPTFF performed under vibration was able to achieve single pass concentration factors of 20× at a feed flux of 17.2 L/m2/h, while the non‐vibratory system showed rapid fouling at much lower concentration factors. Furthermore, the vibratory module achieved a 6‐fold higher concentration factor compared to a screened channel cassette. Long‐term filtration experiments demonstrated that the vibratory system could concentrate a 20 g/L protein solution to 100 g/L using a single cassette with stable operation for more than 8 h without protein aggregation. This work highlights the potential opportunity to develop vibratory SPTFF systems for intensified bioprocessing.
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- Award ID(s):
- 2310832
- PAR ID:
- 10641798
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Biotechnology Journal
- Volume:
- 20
- Issue:
- 9
- ISSN:
- 1860-6768
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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