Abstract Continuous manufacturing platforms and membrane chromatography are process technologies with the potential to reduce production costs and minimize process variability in monoclonal antibody production. This study presents a simulation and optimization framework to perform techno‐economic analyses of these strategies. Multi‐objective optimization was used to compare batch and continuous multicolumn operating modes and membrane and resin process alternatives, revealing performance differences in productivity and cost of goods attributed to variations in dynamic binding capacity, media geometry, and process residence time. From the set of optimal process configurations, we selected one membrane and one resin platform alternative yielding the highest net present values to undergo sensitivity analyses involving variations in batch cadence and product selling price. For the scenarios considered in this work, membrane continuous platforms showed benefits in the cost of goods and process mass intensity. Their shorter residence time compared to resins positions them as a viable alternative for single‐use capture chromatography. Moreover, this low residence time makes membrane platforms more flexible to changes in throughput, an essential feature for integrating capture into fully continuous processes.
more »
« less
This content will become publicly available on September 1, 2026
Techno‐Economic Analysis of Membrane‐Based Purification Platforms for AAV Vector Production
ABSTRACT Technologies for large‐scale manufacturing of viral vectors for gene therapies, such as tangential flow filtration and membrane chromatography, are under development. In these early stages of process development, techno‐economic analyses are useful for identifying membrane properties yielding the greatest impact on process performance. In this study, we adapted a techno‐economic framework used for monoclonal antibody capture for adeno‐associated viral vector purification. We added mechanistic models to simulate flux decline during harvesting and separating full and empty capsids during polishing. Graphical user interfaces were added to help users explore the design search space. We selected a base process and manipulated selected variables to see their impact on large‐scale manufacturing performance. These sensitivity analyses revealed that, under the selected process conditions, increasing module capacity reduces cost of goods more effectively than increasing operational flux in tangential flow membrane filtration modules for virus harvesting. Membrane chromatography columns with relatively low dynamic binding capacity (DBC) and short residence time (RT) offered similar or better economic performance than those with high DBC and long RT. Additionally, the difference in equilibrium solid‐phase concentration between full and empty capsids as a function of salt concentration significantly affects purity.
more »
« less
- Award ID(s):
- 2011902
- PAR ID:
- 10634245
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Biotechnology and Bioengineering
- Volume:
- 122
- Issue:
- 9
- ISSN:
- 0006-3592
- Page Range / eLocation ID:
- 2400 to 2409
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
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.more » « less
-
The rapid development of adeno-associated viral vectors (AAV) to treat genetic disease has placed increased emphasis on the design of efficient downstream manufacturing processes. This study investigated the potential of using single pass tangential flow filtration (SPTFF) as a novel means of concentrating and purifying AAV clarified cell lysate (CCL). AAV stability studies revealed the shear-sensitive nature of the AAV capsids, with evidence of aggregation and fragmentation following repeated passages through a peristaltic pump (as would occur during batch ultrafiltration). SPTFF experiments focused on first identifying the membrane(s) that permitted high yield of AAV (negligible sieving into the permeate) along with substantial host cell protein (HCP) removal. Experiments were then performed at various permeate fluxes, which revealed that stable SPTFF processes can be achieved by operating below a critical flux for fouling (Jfoul). 300 kDa regenerated cellulose (RC) membranes were identified as optimal for this application, given their ability to provide complete AAV retention with high removal of HCP (>90%) when operated below Jfoul. The critical flux during SPTFF was increased by preconditioning the CCL through a positively-charged adsorptive filter, which reduced the concentration of foulants prior to SPTFF. These studies provide the first demonstration of SPTFF for the concentration and purification of AAV clarified cell lysate while minimizing shear exposure.more » « less
-
Adeno-associated viral vectors (AAVs) are the predominant viral vectors used for gene therapy applications. A significant challenge in obtaining effective doses is removing non-therapeutic empty viral capsids lacking DNA cargo. Current methods for separating full (gene-containing) and empty capsids are challenging to scale, produce low product yields, are slow, and are difficult to operationalize for continuous biomanufacturing. This communication demonstrates the feasibility of separating full and empty capsids by ultrafiltration. Separation performance was quantified by measuring the sieving coefficients for full and empty capsids using ELISA, qPCR, and an infectivity assay based on the live cell imaging of green fluorescent protein expression. We demonstrated that polycarbonate track-etched membranes with a pore size of 30 nm selectively permeated empty capsids to full capsids, with a high recovery yield (89%) for full capsids. The average sieving coefficients of full and empty capsids obtained through ELISA/qPCR were calculated as 0.25 and 0.49, indicating that empty capsids were about twice as permeable as full capsids. Establishing ultrafiltration as a viable unit operation for separating full and empty AAV capsids has implications for developing the scale-free continuous purification of AAVs.more » « less
-
ABSTRACT To enable adeno‐associated viral vectors (AAV) to achieve their maximum potential, next‐generation manufacturing processes must be developed to make gene therapies more affordable and accessible. This study focused on the design of two different intensified AAV downstream manufacturing processes at bench and pilot scale. Novel clarification methods were studied at bench scale, including the use of BioOptimal™ MF‐SL tangential flow microfilters for continuous removal of cell debris. Membrane adsorbers were used for further clarification, including DNA removal. Single pass tangential flow filtration (SPTFF) was implemented at bench scale by feeding the clarified cell lysate (CCL) into two Pellicon XL50 cassettes with 100 kDa regenerated cellulose membranes. At pilot scale, a multi‐membrane staged SPTFF module was designed to concentrate 10 L of AAV CCL. Both SPTFF systems provided 12X inline volumetric concentration with AAV yield > 99% after an appropriate buffer chase. Host cell protein removal was 48% and 37% for the bench and pilot scale processes, respectively. As an initial proof‐of‐concept, an integrated process was developed at pilot‐scale which linked clarification, SPTFF, and affinity chromatography. The integrated process offered an 81% reduction in total operating time (due to the reduced volume of load material for the affinity column after preconcentration by SPTFF), 36% improvement in affinity resin utilization (due to the higher AAV concentration in the column load), and an estimated 10% reduction in raw material costs. These improvements translated to an 8.5‐fold increase in overall productivity compared to an equivalent batch process, underscoring the potential for SPTFF to intensify large‐scale AAV downstream processing.more » « less
An official website of the United States government
