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Sripada SA, Hosseini M, Ramesh S, Wang J, Ritola K, Menegatti S, Daniele MA. Advances and opportunities in process analytical technologies for viral vector manufacturing. Biotechnol Adv 2024; 74:108391. [PMID: 38848795 DOI: 10.1016/j.biotechadv.2024.108391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 03/14/2024] [Accepted: 05/29/2024] [Indexed: 06/09/2024]
Abstract
Viral vectors are an emerging, exciting class of biologics whose application in vaccines, oncology, and gene therapy has grown exponentially in recent years. Following first regulatory approval, this class of therapeutics has been vigorously pursued to treat monogenic disorders including orphan diseases, entering hundreds of new products into pipelines. Viral vector manufacturing supporting clinical efforts has spurred the introduction of a broad swath of analytical techniques dedicated to assessing the diverse and evolving panel of Critical Quality Attributes (CQAs) of these products. Herein, we provide an overview of the current state of analytics enabling measurement of CQAs such as capsid and vector identities, product titer, transduction efficiency, impurity clearance etc. We highlight orthogonal methods and discuss the advantages and limitations of these techniques while evaluating their adaptation as process analytical technologies. Finally, we identify gaps and propose opportunities in enabling existing technologies for real-time monitoring from hardware, software, and data analysis viewpoints for technology development within viral vector biomanufacturing.
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Affiliation(s)
- Sobhana A Sripada
- Department of Chemical and Biomolecular Engineering, North Carolina State University, 911 Partners Way, Raleigh, NC, 27695, USA
| | - Mahshid Hosseini
- Joint Department of Biomedical Engineering, North Carolina State University, and University of North Carolina, Chapel Hill, 911 Oval Dr., Raleigh, NC 27695, USA
| | - Srivatsan Ramesh
- Department of Chemical and Biomolecular Engineering, North Carolina State University, 911 Partners Way, Raleigh, NC, 27695, USA
| | - Junhyeong Wang
- Joint Department of Biomedical Engineering, North Carolina State University, and University of North Carolina, Chapel Hill, 911 Oval Dr., Raleigh, NC 27695, USA
| | - Kimberly Ritola
- North Carolina Viral Vector Initiative in Research and Learning (NC-VVIRAL), North Carolina State University, 890 Oval Dr, Raleigh, NC 27695, USA; Neuroscience Center, Brain Initiative Neurotools Vector Core, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Stefano Menegatti
- Department of Chemical and Biomolecular Engineering, North Carolina State University, 911 Partners Way, Raleigh, NC, 27695, USA; North Carolina Viral Vector Initiative in Research and Learning (NC-VVIRAL), North Carolina State University, 890 Oval Dr, Raleigh, NC 27695, USA; Biomanufacturing Training and Education Center, North Carolina State University, 890 Main Campus Dr, Raleigh, NC 27695, USA.
| | - Michael A Daniele
- Joint Department of Biomedical Engineering, North Carolina State University, and University of North Carolina, Chapel Hill, 911 Oval Dr., Raleigh, NC 27695, USA; North Carolina Viral Vector Initiative in Research and Learning (NC-VVIRAL), North Carolina State University, 890 Oval Dr, Raleigh, NC 27695, USA; Department of Electrical and Computer Engineering, North Carolina State University, 890 Oval Dr, Raleigh, NC 27695, USA.
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2
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Shastry S, Chu W, Barbieri E, Greback-Clarke P, Smith WK, Cummings C, Minzoni A, Pancorbo J, Gilleskie G, Ritola K, Daniele MA, Johnson TF, Menegatti S. Rational design and experimental evaluation of peptide ligands for the purification of adeno-associated viruses via affinity chromatography. Biotechnol J 2024; 19:e2300230. [PMID: 37728197 DOI: 10.1002/biot.202300230] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/21/2023]
Abstract
Adeno-associated viruses (AAVs) have acquired a central role in modern medicine as delivery agents for gene therapies targeting rare diseases. While new AAVs with improved tissue targeting, potency, and safety are being introduced, their biomanufacturing technology is lagging. In particular, the AAV purification pipeline hinges on protein ligands for the affinity-based capture step. While featuring excellent AAV binding capacity and selectivity, these ligands require strong acid (pH <3) elution conditions, which can compromise the product's activity and stability. Additionally, their high cost and limited lifetime has a significant impact on the price tag of AAV-based therapies. Seeking to introduce a more robust and affordable affinity technology, this study introduces a cohort of peptide ligands that (i) mimic the biorecognition activity of the AAV receptor (AAVR) and anti-AAV antibody A20, (ii) enable product elution under near-physiological conditions (pH 6.0), and (iii) grant extended reusability by withstanding multiple regenerations. A20-mimetic CYIHFSGYTNYNPSLKSC and AAVR-mimetic CVIDGSQSTDDDKIC demonstrated excellent capture of serotypes belonging to distinct clones/clades - namely, AAV1, AAV2, AAV5, AAV6, AAV8, and AAV9. This corroborates the in silico models documenting their ability to target regions of the viral capsid that are conserved across all serotypes. CVIDGSQSTDDDKIC-Toyopearl resin features binding capacity (≈1014 vp mL-1 ) and product yields (≈60%-80%) on par with commercial adsorbents, and purifies AAV2 from HEK293 and Sf9 cell lysates with high recovery (up to 78%), reduction of host cell proteins (up to 700-fold), and high transduction activity (up to 65%).
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Affiliation(s)
- Shriarjun Shastry
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
- Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, North Carolina, USA
| | - Wenning Chu
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Eduardo Barbieri
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Paul Greback-Clarke
- Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, North Carolina, USA
| | - William K Smith
- Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, North Carolina, USA
| | - Christopher Cummings
- Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, North Carolina, USA
| | - Arianna Minzoni
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Jennifer Pancorbo
- Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, North Carolina, USA
| | - Gary Gilleskie
- Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, North Carolina, USA
| | - Kimberly Ritola
- Neuroscience Center, Brain Initiative Neurotools Vector Core, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- North Carolina Viral Vector Initiative in Research and Learning (NC-VVIRAL), North Carolina State University, Raleigh, North Carolina, USA
| | - Michael A Daniele
- North Carolina Viral Vector Initiative in Research and Learning (NC-VVIRAL), North Carolina State University, Raleigh, North Carolina, USA
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill, Raleigh, North Carolina, USA
| | - Thomas F Johnson
- Department of Biochemical Engineering, University College London, London, UK
| | - Stefano Menegatti
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
- Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, North Carolina, USA
- North Carolina Viral Vector Initiative in Research and Learning (NC-VVIRAL), North Carolina State University, Raleigh, North Carolina, USA
- LigaTrap Technologies LLC, Raleigh, North Carolina, USA
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3
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Kilgore R, Minzoni A, Shastry S, Smith W, Barbieri E, Wu Y, LeBarre JP, Chu W, O'Brien J, Menegatti S. The downstream bioprocess toolbox for therapeutic viral vectors. J Chromatogr A 2023; 1709:464337. [PMID: 37722177 DOI: 10.1016/j.chroma.2023.464337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/24/2023] [Accepted: 08/27/2023] [Indexed: 09/20/2023]
Abstract
Viral vectors are poised to acquire a prominent position in modern medicine and biotechnology owing to their role as delivery agents for gene therapies, oncolytic agents, vaccine platforms, and a gateway to engineer cell therapies as well as plants and animals for sustainable agriculture. The success of viral vectors will critically depend on the availability of flexible and affordable biomanufacturing strategies that can meet the growing demand by clinics and biotech companies worldwide. In this context, a key role will be played by downstream process technology: while initially adapted from protein purification media, the purification toolbox for viral vectors is currently undergoing a rapid expansion to fit the unique biomolecular characteristics of these products. Innovation efforts are articulated on two fronts, namely (i) the discovery of affinity ligands that target adeno-associated virus, lentivirus, adenovirus, etc.; (ii) the development of adsorbents with innovative morphologies, such as membranes and 3D printed monoliths, that fit the size of viral vectors. Complementing these efforts are the design of novel process layouts that capitalize on novel ligands and adsorbents to ensure high yield and purity of the product while safeguarding its therapeutic efficacy and safety; and a growing panel of analytical methods that monitor the complex array of critical quality attributes of viral vectors and correlate them to the purification strategies. To help explore this complex and evolving environment, this study presents a comprehensive overview of the downstream bioprocess toolbox for viral vectors established in the last decade, and discusses present efforts and future directions contributing to the success of this promising class of biological medicines.
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Affiliation(s)
- Ryan Kilgore
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States.
| | - Arianna Minzoni
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States
| | - Shriarjun Shastry
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States; Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, NC 27695, United States
| | - Will Smith
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States
| | - Eduardo Barbieri
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States
| | - Yuxuan Wu
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States
| | - Jacob P LeBarre
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States
| | - Wenning Chu
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States
| | - Juliana O'Brien
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, United States
| | - Stefano Menegatti
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States; Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, NC 27695, United States; North Carolina Viral Vector Initiative in Research and Learning, North Carolina State University, Raleigh, NC 27695, United States
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Jiang Z, Dalby PA. Challenges in scaling up AAV-based gene therapy manufacturing. Trends Biotechnol 2023; 41:1268-1281. [PMID: 37127491 DOI: 10.1016/j.tibtech.2023.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 04/05/2023] [Accepted: 04/06/2023] [Indexed: 05/03/2023]
Abstract
Accelerating the scale up of adeno-associated virus (AAV) manufacture is highly desirable to meet the increased demand for gene therapies. However, the development of bioprocesses for AAV gene therapies remains time-consuming and challenging. The quality by design (QbD) approach ensures bioprocess designs that meet the desired product quality and safety profile. Rapid stress tests, developability screens, and scale-down technologies have the potential to streamline AAV product and manufacturing bioprocess development within the QbD framework. Here we review how their successful use for antibody manufacture development is translating to AAV, but also how this will depend critically on improved analytical methods and adaptation of the tools as more understanding is gained on the critical attributes of AAV required for successful therapy.
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Affiliation(s)
- Ziyu Jiang
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, UK.
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, UK.
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Grossen P, Skaripa Koukelli I, van Haasteren J, H E Machado A, Dürr C. The ice age - A review on formulation of Adeno-associated virus therapeutics. Eur J Pharm Biopharm 2023; 190:1-23. [PMID: 37423416 DOI: 10.1016/j.ejpb.2023.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/30/2023] [Accepted: 07/06/2023] [Indexed: 07/11/2023]
Abstract
Gene therapies offer promising therapeutic alternatives for many disorders that currently lack efficient treatment options. Due to their chemical nature and physico-chemical properties, delivery of polynucleic acids into target cells and subcellular compartments remains a significant challenge. Adeno-associated viruses (AAV) have gained a lot of interest for the efficient delivery of therapeutic single-stranded DNA (ssDNA) genomes over the past decades. More than a hundred products have been tested in clinical settings and three products have received market authorization by the US FDA in recent years. A lot of effort is being made to generate potent recombinant AAV (rAAV) vectors that show favorable safety and immunogenicity profiles for either local or systemic administration. Manufacturing processes are gradually being optimized to deliver a consistently high product quality and to serve potential market needs beyond rare indications. In contrast to protein therapeutics, most rAAV products are still supplied as frozen liquids within rather simple formulation buffers to enable sufficient product shelf life, significantly hampering global distribution and access. In this review, we aim to outline the hurdles of rAAV drug product development and discuss critical formulation and composition aspects of rAAV products under clinical evaluation. Further, we highlight recent development efforts in order to achieve stable liquid or lyophilized products. This review therefore provides a comprehensive overview on current state-of-the-art rAAV formulations and can further serve as a map for rational formulation development activities in the future.
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Affiliation(s)
- Philip Grossen
- F.Hoffmann-La Roche AG, Pharma Technical Development, Pharmaceutical Development and Supplies EU, Grenzacherstrasse 124, 4070 Basel, Switzerland.
| | - Irini Skaripa Koukelli
- F.Hoffmann-La Roche AG, Pharma Technical Development, Pharmaceutical Development and Supplies EU, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Joost van Haasteren
- F.Hoffmann-La Roche AG, Cell and Gene Therapy Unit, Gene Therapy Development Clinical Manufacturing, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Alexandra H E Machado
- F.Hoffmann-La Roche AG, Pharma Technical Development, Pharmaceutical Development and Supplies EU, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Christoph Dürr
- F.Hoffmann-La Roche AG, Pharma Technical Development, Pharmaceutical Development and Supplies EU, Grenzacherstrasse 124, 4070 Basel, Switzerland
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Gronke RS, Ruanjaikaen K, Delavari A, Immel-Brown JP, Penrod JC, Lam Y, Antia FD. Use of ultrafiltration/diafiltration for the processing of antisense oligonucleotides. Biotechnol Prog 2023; 39:e3350. [PMID: 37186510 DOI: 10.1002/btpr.3350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 04/11/2023] [Accepted: 04/12/2023] [Indexed: 05/17/2023]
Abstract
Ultrafiltration/diafiltration (UF/DF) has been the hallmark for concentrating and buffer exchange of protein and peptide-based therapeutics for years. Here we examine the capabilities and limitations of UF/DF membranes to process oligonucleotides using antisense oligonucleotides (ASOs) as a model. Using a 3 kDa UF/DF membrane, oligonucleotides as small as 6 kDa are shown to have low sieving coefficients (<0.008) and thus can be concentrated to high concentrations (≤200 mg/mL) with high yield (≥95%) and low viscosity (<15 centipoise), provided the oligonucleotide is designed not to undergo self-hybridization. In general, the oligonucleotide should be at least twice the reported membrane molecular weight cutoff for robust retention. Regarding diafiltration, results show that a small amount of salt is necessary to maintain adequate flux at concentrations exceeding about 40 mg/mL. Removal of salts along with residual solvents and small molecule process-related impurities can be robust provided they are not positively charged as the interaction with the oligonucleotide can prevent passage through the membrane, even for common divalent cations such as calcium or magnesium. Overall, UF/DF is a valuable tool to utilize in oligonucleotide processing, especially as a final drug substance formulation step that enables a liquid active pharmaceutical ingredient.
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Affiliation(s)
- Robert S Gronke
- Technical Development, Biogen, Inc, Cambridge, Massachusetts, USA
| | - Krisada Ruanjaikaen
- Technical Operations, Intellia Therapeutics, Inc, Cambridge, Massachusetts, USA
| | - Armin Delavari
- Technical Development, Biogen, Inc, Cambridge, Massachusetts, USA
| | | | - Joseph C Penrod
- Technical Development, Biogen, Inc, Durham, North Carolina, USA
| | - Yik Lam
- Technical Development, Biogen, Inc, Durham, North Carolina, USA
| | - Firoz D Antia
- Technical Development, Biogen, Inc, Cambridge, Massachusetts, USA
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Chaubal AS, Zydney AL. Single-Pass Tangential Flow Filtration (SPTFF) of Nanoparticles: Achieving Sustainable Operation with Dilute Colloidal Suspensions for Gene Therapy Applications. MEMBRANES 2023; 13:433. [PMID: 37103860 PMCID: PMC10143681 DOI: 10.3390/membranes13040433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/09/2023] [Accepted: 04/12/2023] [Indexed: 06/19/2023]
Abstract
Recent approval of several viral-vector-based therapeutics has led to renewed interest in the development of more efficient bioprocessing strategies for gene therapy products. Single-Pass Tangential Flow Filtration (SPTFF) can potentially provide inline concentration and final formulation of viral vectors with enhanced product quality due. In this study, SPTFF performance was evaluated using a suspension of 100 nm nanoparticles that mimics a typical lentivirus system. Data were obtained with flat-sheet cassettes having 300 kDa nominal molecular weight cutoff, either in full recirculation or single-pass mode. Flux-stepping experiments identified two critical fluxes, one based on boundary-layer particle accumulation (Jbl) and one based on membrane fouling (Jfoul). The critical fluxes were well-described using a modified concentration polarization model that captures the observed dependence on feed flow rate and feed concentration. Long-duration filtration experiments were conducted under stable SPTFF conditions, with the results suggesting that sustainable performance could potentially be achieved for as much as 6 weeks of continuous operation. These results provide important insights into the potential application of SPTFF for the concentration of viral vectors in the downstream processing of gene therapy agents.
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Li C, Ma Y, Zhi X, Peng G. Optimization of ultrasonic assisted membrane strategy for saponins from Gynostemma Pentaphyllum with response surface methodology. Food Sci Biotechnol 2023; 32:319-328. [PMID: 36778093 PMCID: PMC9905334 DOI: 10.1007/s10068-022-01196-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/13/2022] [Accepted: 10/24/2022] [Indexed: 11/09/2022] Open
Abstract
Gynostemma pentaphyllum saponin has a variety of biological properties. Classic separation methods of saponin, such as resin absorption and preparative chromatography are limited by environmental pollution and high cost. In the study, ultrasonic assisted membrane separation was firstly used to purify saponin from Gynostemma pentaphyllum. Total proteins, polysaccharides, saponin, gypenoside A and rutin were selected as indexes to optimize the pretreatment and purification parameters by response surface methodology. The fitted models were significant (p < 0.05) and the optimal conditions were: (1) removing protein and polysaccharides by MWCO 10,000 Da, ultrasonic power 400 W and pH 7.8; (2) separation flavonoids from saponin by MWCO 1000 Da, ultrasonic power 300 W and pH 7.9. The difficulty in separating saponin from flavonoids was solved by releasing flavonoids from micelles with ultrasonic assisted membrane method. The saponin content in Gynostemma pentaphyllum extracts reached 82.81%, which was more than four times of that obtained with resin adsorption method. The protective effect of saponins on SH-SY5Y cells injury induced by H2O2 was better than that of Gynostemma pentaphyllum extracts. The study suggested that ultrasonic assisted membrane method would be widely applied in the preparation of food materials.
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Affiliation(s)
- Cunyu Li
- College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023 People’s Republic of China
- Jiangsu Collaborative Innovation Centers of Chinese Medicinal Resources Industrialization, Nanjing, 210023 People’s Republic of China
- Jiangsu Engineering Research Centers of Classical Prescription, Nanjing, 210023 People’s Republic of China
| | - Yun Ma
- The Fourth People’s Hospital of Taizhou City, Taizhou, 225300 People’s Republic of China
| | - Xinglei Zhi
- College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023 People’s Republic of China
- Jiangsu Collaborative Innovation Centers of Chinese Medicinal Resources Industrialization, Nanjing, 210023 People’s Republic of China
| | - Guoping Peng
- College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023 People’s Republic of China
- Jiangsu Collaborative Innovation Centers of Chinese Medicinal Resources Industrialization, Nanjing, 210023 People’s Republic of China
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Chu LK, Wickramasinghe SR, Qian X, Zydney AL. Retention and Fouling during Nanoparticle Filtration: Implications for Membrane Purification of Biotherapeutics. MEMBRANES 2022; 12:membranes12030299. [PMID: 35323774 PMCID: PMC8953984 DOI: 10.3390/membranes12030299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 02/28/2022] [Accepted: 03/04/2022] [Indexed: 02/06/2023]
Abstract
One major challenge in the development of nanoparticle-based therapeutics, including viral vectors for the delivery of gene therapies, is the development of cost-effective purification technologies. The objective of this study was to examine fouling and retention behaviors during the filtration of model nanoparticles through membranes of different pore sizes and the effect of solution conditions. Data were obtained with 30 nm fluorescently labeled polystyrene latex nanoparticles using both cellulosic and polyethersulfone membranes at a constant filtrate flux, and both pressure and nanoparticle transmission were evaluated as a function of cumulative filtrate volume. The addition of NaCl caused a delay in nanoparticle transmission and an increase in fouling. Nanoparticle transmission was also a function of particle hydrophobicity. These results provide important insights into the factors controlling transmission and fouling during nanoparticle filtration as well as a framework for the development of membrane processes for the purification of nanoparticle-based therapeutics.
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Affiliation(s)
- Liang-Kai Chu
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA;
| | - S. Ranil Wickramasinghe
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, AK 72701, USA;
| | - Xianghong Qian
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AK 72701, USA;
| | - Andrew L. Zydney
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA;
- Correspondence:
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Quan DN, Shiloach J. rAAV Production and Titration at the Microscale for High-Throughput Screening. Hum Gene Ther 2022; 33:94-102. [PMID: 34328798 PMCID: PMC8819507 DOI: 10.1089/hum.2021.080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
In the literature, there are few high-throughput screens or even methods for high-throughput screens of recombinant adeno-associated virus (rAAV) production despite potential benefits to research and production. In this study, a generalizable high-throughput relative rAAV titration method is examined within the context of an siRNA screen as siRNA knockdown is a common means of pathway engineering in bioproduction. Crude samples generated from transfected HEK293T/17 cultures were subjected to quantitative PCR (qPCR) and used to transduce COS7 cells to assess relative differences in genomic and infectious rAAV titer, respectively, at the 384-well scale, evaluating both supernatant and lysed samples. To evaluate relevant differences in titer for conditions that could be used in an actual screen, cultures subjected to an siRNA reverse transfection and subsequent rAAV forward transfection were also tested. The delayed forward rAAV triple-plasmid transfection was not seen to affect the siRNA activity of tested controls, while siRNA transfection was shown to measurably impact rAAV titer. Effective differentiation between infectious titer levels was dependent upon the choice of sample dilution, but trends between qPCR and infectious titer assays were consistent across sample sets.
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Affiliation(s)
- David Nathan Quan
- NIDDK Biotechnology Core, NIDDK, National Institutes of Health, Bethesda, Maryland, USA
| | - Joseph Shiloach
- NIDDK Biotechnology Core, NIDDK, National Institutes of Health, Bethesda, Maryland, USA.,Correspondence: Dr. Joseph Shiloach, NIDDK Biotechnology Core, National Institutes of Health, 14 Service Road W, Bethesda, MD 20894, USA.
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