Recent advances in bioprocessing application of membrane chromatography

Continuous multi-column capture of monoclonal antibodies with convective diffusive membrane adsorbers

Downstream processing is the bottleneck in the continuous manufacturing of monoclonal antibodies (mAbs). To overcome throughput limitations, two different continuous processes with a novel convective diffusive protein A membrane adsorber (MA) were investigated: the rapid cycling parallel multi-column chromatography (RC-PMCC) process and the rapid cycling simulated moving bed (RC-BioSMB) process. First, breakthrough curve experiments were performed to investigate the influence of the flow rate on the mAb dynamic binding capacity and to calculate the duration of the loading steps. In addition, customized control software was developed for an automated MA exchange in case of pressure increase due to membrane fouling to enable robust, uninterrupted, and continuous processing. Both processes were performed for 4 days with 0.61 g L-1 mAb-containing filtrate and process performance, product purity, productivity, and buffer consumption were compared. The mAb was recovered with a yield of approximately 90% and productivities of 1010 g L-1 d-1 (RC-PMCC) and 574 g L-1 d-1 (RC-BioSMB). At the same time, high removal of process-related impurities was achieved with both processes, whereas the buffer consumption was lower for the RC-BioSMB process. Finally, the attainable productivity for perfusion bioreactors of different sizes with suitable MA sizes was calculated to demonstrate the potential to operate both processes on a manufacturing scale with bioreactor volumes of up to 2000 L.

Toward microfluidic continuous-flow and intelligent downstream processing of biopharmaceuticals

Biopharmaceuticals have emerged as powerful therapeutic agents, revolutionizing the treatment landscape for various diseases, including cancer, infectious diseases, autoimmune and genetic disorders. These biotherapeutics pave the way for precision medicine with their unique and targeted capabilities. The production of high-quality biologics entails intricate manufacturing processes, including cell culture, fermentation, purification, and formulation, necessitating specialized facilities and expertise. These complex processes are subject to rigorous regulatory oversight to evaluate the safety, efficacy, and quality of biotherapeutics prior to clinical approval. Consequently, these drugs undergo extensive purification unit operations to achieve high purity by effectively removing impurities and contaminants. The field of personalized precision medicine necessitates the development of novel and highly efficient technologies. Microfluidic technology addresses unmet needs by enabling precise and compact separation, allowing rapid, integrated and continuous purification modules. Moreover, the integration of intelligent biomanufacturing systems with miniaturized devices presents an opportunity to significantly enhance the robustness of complex downstream processing of biopharmaceuticals, with the benefits of automation and advanced control. This allows seamless data exchange, real-time monitoring, and synchronization of purification steps, leading to improved process efficiency, data management, and decision-making. Integrating autonomous systems into biopharmaceutical purification ensures adherence to regulatory standards, such as good manufacturing practice (GMP), positioning the industry to effectively address emerging market demands for personalized precision nano-medicines. This perspective review will emphasize on the significance, challenges, and prospects associated with the adoption of continuous, integrated, and intelligent methodologies in small-scale downstream processing for various types of biologics. By utilizing microfluidic technology and intelligent systems, purification processes can be enhanced for increased efficiency, cost-effectiveness, and regulatory compliance, shaping the future of biopharmaceutical production and enabling the development of personalized and targeted therapies.

Improved Protein Removal Performance of PES Hollow-Fiber Ultrafiltration Membrane with Sponge-like Structure

The research used polyethersulfone (PES) as a membrane material, polyvinylpyrrolidone (PVP) k30 and polyethylene glycol 400 (PEG 400) as water-soluble additives, and dimethylacetamide (DMAc) as a solvent to prepare hollow-fiber ultrafiltration membranes through a nonsolvent-induced phase separation (NIPS) process. The hydrophilic nature of PVP-k30 and PEG caused them to accumulate on the membrane surface during phase separation. The morphology, chemical composition, surface charge, and pore size of the PES membranes were evaluated by SEM, FTIR, zeta potential, and dextran filtration experiments. The paper also investigated how different spinning solution compositions affected membrane morphology and performance. The separation efficiency of membranes with four different morphologies was tested in single-protein and double-protein mixed solutions. The protein separation effectiveness of the membrane was studied through molecular weight cutoff, zeta potential, and static protein adsorption tests. In addition, the operating pressure and pH value were adjusted to improve ultrafiltration process conditions. The PES membrane with an intact sponge-like structure showed the highest separation factor of 11, making it a prime candidate membrane for the separation of bovine serum albumin (BSA) and lysozyme (LYS). The membrane had a minimal static protein adsorption capacity of 48 mg/cm2 and had excellent anti-fouling properties. When pH = 4, the BSA retention rate was 93% and the LYS retention rate was 23%. Furthermore, it exhibited excellent stability over a pH range of 1-13, confirming its suitability for protein separation applications.

Purification of monoclonal antibodies using novel 3D printed ordered stationary phases

3D printing offers the unprecedented ability to fabricate chromatography stationary phases with bespoke 3D morphology as opposed to traditional packed beds of spherical beads. The restricted range of printable materials compatible with chromatography is considered a setback for its industrial implementation. Recently, we proposed a novel ink that exhibits favourable printing performance (printing time ∼100 mL/h, resolution ∼200 µm) and broadens the possibilities for a range of chromatography applications thanks to its customisable surface chemistry. In this work, this ink was used to fabricate 3D printed ordered columns with 300 µm channels for the capture and polishing of therapeutic monoclonal antibodies. The columns were initially assessed for leachables and extractables, revealing no material propensity for leaching. Columns were then functionalised with protein A and SO3 ligands to obtain affinity and strong cation exchangers, respectively. 3D printed protein A columns showed >85 % IgG recovery from harvested cell culture fluid with purities above 98 %. Column reusability was evaluated over 20 cycles showing unaffected performance. Eluate samples were analysed for co-eluted protein A fragments, host cell protein and aggregates. Results demonstrate excellent HCP clearance (logarithmic reduction value of > 2.5) and protein A leakage in the range of commercial affinity resins (<100 ng/mg). SO3 functionalised columns employed for polishing achieved removal of leaked Protein A (down to 10 ng/mg) to meet regulatory expectations of product purity. This work is the first implementation of 3D printed columns for mAb purification and provides strong evidence for their potential in industrial bioseparations.

Novel multimodal cation-exchange membrane for the purification of a single-chain variable fragment from Pichia pastoris supernatant

A novel salt-tolerant cation-exchange membrane, prepared with a multimodal ligand, 2-mercaptopyridine-3-carboxylic acid (MMC-MPCA), was examined for its purification properties in a bind-and-elute mode from the high conductivity supernatant of a Pichia pastoris fermentation producing and secreting a single-chain variable fragment (scFv). If successful, this approach would eliminate the need for a buffer exchange prior to product capture by ion-exchange. Two fed-batch fermentations of Pichia pastoris resulted in fermentation supernatants reaching an scFv titer of 395.0 mg/L and 555.7 mg/L, both with a purity of approximately 83 %. The MMC-MPCA membrane performance was characterized in terms of pH, residence time (RT), scFv load, and scFv concentration to identify the resulting dynamic binding capacity (DBC), yield, and purity achieved under optimal conditions. The MMC-MPCA membrane exhibited the highest DBC of 39.06 mg/mL at pH 5.5, with a residence time of 1 min, while reducing the pH below 5.0 resulted in a significant decrease of the DBC to around 2.5 mg/mL. With almost no diffusional limitations, reducing the RT from 2 to 0.2 min did not negatively impact the DBC of the MMC-MPCA membrane, resulting in a significant improvement in productivity of up to 180 mg/mL/min at 0.2 min RT. Membrane fouling was observed when reusing the membranes at 0.2 and 0.5 min RT, likely due to the enhanced adsorption of impurities on the membrane. Changing the amount of scFv loaded onto the membrane column did not show any changes in yield, instead a 10-20 % loss of scFv was observed, which suggested that some of the produced scFv were fragmented or had aggregated. When performing the purification under the optimized conditions, the resulting purity of the product improved from 83 % to approximately 92-95 %.

Design and characterization of an electrochemically-modulated membrane chromatography device

Membrane separations offer a compelling alternative to traditional chromatographic methods by overcoming mass transport limitations. We introduce an additional degree of freedom in modulating membrane chromatography by using metalized membranes in a potential-driven process. Investigating the impact of a gold coating on membrane characteristics, the sputtered gold layer enhances the surface conductivity with stable electrochemical behavior. However, this comes at the expense of reduced permeability, wettability, and static binding capacity (∼ 474 µg g-1 of maleic acid). The designed device displayed a homogenous flow distribution, and the membrane electrodes exhibit predominantly capacitive behavior during potential application. Modulating the electrical potential during the adsorption and desorption phase strongly influenced the binding and elution behavior of anion-exchange membranes. Switching potentials between ±1.0 V vs. Ag/AgCl induces desorption, confirming the process principle. Elution efficiency reaches up to 58 % at -1.0 V vs. Ag/AgCl in the desorption phase without any alteration of the mobile phase. Increasing the potential perturbation ranging from +1.0 V to -1.0 V vs. Ag/AgCl resulted in reduced peak width and improved elution behavior, demonstrating the feasibility of electrochemically-modulated membrane chromatography. The developed process has great potential as a gentle and sustainable separation step in the biotechnological and chemical industry.

Development of a New Affinity Gold Polymer Membrane with Immobilized Protein A

New and highly selective stationary phases for affinity membrane chromatography have the potential to significantly enhance the efficiency and specificity of therapeutic protein purification by reduced mass transfer limitations. This work developed and compared different immobilization strategies for recombinant Protein A ligands to a gold-sputtered polymer membrane for antibody separation in terms of functionalization and immobilization success, protein load, and stability. Successful, functionalization was validated via X-ray photoelectron spectroscopy (XPS). Here, a recombinant Protein A ligand was coupled by N-hydroxysuccinimide (NHS)/N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) chemistry to carboxy-functionalized, gold-sputtered membranes. We achieved a binding capacity of up to 104 ± 17 mg of the protein ligand per gram of the gold-sputtered membrane. The developed membranes were able to successfully capture and release the monoclonal antibody (mAb) Trastuzumab, as well as antibodies from fresh frozen human blood plasma in both static and dynamic setups. Therefore, they demonstrated successful functionalization and immobilization strategies. The antibody load was tested using bicinchoninic acid (BCA), ultraviolet-visible spectroscopy (UV-vis) measurements, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The outcome is a fully functional affinity membrane that can be implemented in a variety of different antibody purification processes, eliminating the need for creating individualized strategies for modifying the surface to suit different substrates or conditions.

Continuous multi-membrane chromatography of large viral particles

Continuous multi-column chromatography (CMCC) has been successfully implemented to address biopharmaceutical biomolecule instability, to improve process efficiency, and to reduce facility footprint and capital cost. This paper explores the implementation of a continuous multi-membrane chromatography (CMMC) process, using four membrane units, for a large viral particle in just few weeks. CMMC improves the efficiency of the chromatography step by enabling higher loads with smaller membranes for multiple cycles of column use and enables steady-state continuous bioprocessing. The separation performance of CMMC was compared to a conventional batch chromatographic capture step used at full manufacturing scale. The product step yield was 80% using CMMC versus 65% in batch mode while increasing slightly the relative purity. Furthermore, the total amount of membrane area required for the CMMC approach was approximately 10% of the area needed for batch operation, while realizing similar processing times. Since CMMC uses smaller membrane sizes, it can take advantage of the high flow rates achievable for membrane chromatography that are not typically possible at larger membrane scales due to skid flow rate limitations. As such, CMMC offers the potential for more efficient and cost-effective purification trains.

Affinity and Pseudo-Affinity Membrane Chromatography for Viral Vector and Vaccine Purifications: A Review

Several chromatographic approaches have been established over the last decades for the production of pharmaceutically relevant viruses. Due to the large size of these products compared to other biopharmaceuticals, e.g., proteins, convective flow media have proven to be superior to bead-based resins in terms of process productivity and column capacity. One representative of such convective flow materials is membranes, which can be modified to suit the particular operating principle and are also suitable for economical single-use applications. Among the different membrane variants, affinity surfaces allow for the most selective separation of the target molecule from other components in the feed solution, especially from host cell-derived DNA and proteins. A successful membrane affinity chromatography, however, requires the identification and implementation of ligands, which can be applied economically while at the same time being stable during the process and non-toxic in the case of any leaching. This review summarizes the current evaluation of membrane-based affinity purifications for viruses and virus-like particles, including traditional resin and monolith approaches and the advantages of membrane applications. An overview of potential affinity ligands is given, as well as considerations of suitable affinity platform technologies, e.g., for different virus serotypes, including a description of processes using pseudo-affinity matrices, such as sulfated cellulose membrane adsorbers.

Advances in high-throughput, high-capacity nonwoven membranes for chromatography in downstream processing: A review

Nonwoven membranes are highly engineered fibrous materials that can be manufactured on a large scale from a wide range of different polymers, and their surfaces can be modified using a large variety of different chemistries and ligands. The fiber diameters, surface areas, pore sizes, total porosities, and thicknesses of the nonwoven mats can be carefully controlled, providing many opportunities for creative approaches for the development of novel membranes with unique properties to meet the needs of the future of downstream processing. Fibrous membranes are already finding use in ultrafiltration, microfiltration, depth filtration, and, more recently, in membrane chromatography for product capture and impurity removal. This article summarizes the various methods of manufacturing nonwoven fabrics, and the many methods available for the modification of the fiber surfaces. It also reviews recent studies focused on the use of nonwoven fabric devices in membrane chromatography and provides some perspectives on the challenges that need to be overcome to increase binding capacities, decrease residence times, and reduce pressure drops so that eventually they can replace resin column chromatography in downstream process operations.

On the Performance of a Ready-to-Use Electrospun Sulfonated Poly(Ether Ether Ketone) Membrane Adsorber

Motivated by the need for efficient purification methods for the recovery of valuable resources, we developed a wire-electrospun membrane adsorber without the need for post-modification. The relationship between the fiber structure, functional-group density, and performance of electrospun sulfonated poly(ether ether ketone) (sPEEK) membrane adsorbers was explored. The sulfonate groups enable selective binding of lysozyme at neutral pH through electrostatic interactions. Our results show a dynamic lysozyme adsorption capacity of 59.3 mg/g at 10% breakthrough, which is independent of the flow velocity confirming dominant convective mass transport. Membrane adsorbers with three different fiber diameters (measured by SEM) were fabricated by altering the concentration of the polymer solution. The specific surface area as measured with BET and the dynamic adsorption capacity were minimally affected by variations in fiber diameter, offering membrane adsorbers with consistent performance. To study the effect of functional-group density, membrane adsorbers from sPEEK with different sulfonation degrees (52%, 62%, and 72%) were fabricated. Despite the increased functional-group density, the dynamic adsorption capacity did not increase accordingly. However, in all presented cases, at least a monolayer coverage was obtained, demonstrating ample functional groups available within the area occupied by a lysozyme molecule. Our study showcases a ready-to-use membrane adsorber for the recovery of positively charged molecules, using lysozyme as a model protein, with potential applications in removing heavy metals, dyes, and pharmaceutical components from process streams. Furthermore, this study highlights factors, such as fiber diameter and functional-group density, for optimizing the membrane adsorber's performance.

Efficient adeno-associated virus serotype 5 capture with affinity functionalized nanofiber adsorbents

Adeno-associated viruses (AAVs) are one of the most promising tools for gene therapy applications. These vectors are purified using affinity and ion exchange chromatography, typically using packed beds of resin adsorbents. This leads to diffusion and pressure drop limitations that affect process productivity. Due to their high surface area and porosity, electrospun nanofiber adsorbents offer mass transfer and flow rate advantages over conventional chromatographic media. The present work investigated the use of affinity cellulose-based nanofiber adsorbents for adeno-associated virus serotype 5 (AAV5) capture, evaluating dynamic binding capacity, pressure drop, and AAV5 recovery at residence times (RT) less than 5 s. The dynamic binding capacity was found to be residence time-dependent, but nevertheless higher than 1.0 × 10¹⁴ TP mL^-1 (RT = 1.6 s), with a pressure drop variation of 0.14 MPa obtained after loading more than 2,000 column volumes of clarified AAV5 feedstock. The single affinity chromatography purification step using these new affinity adsorbents resulted in 80% virus recovery, with the removal of impurities comparable to that of bead-based affinity adsorbents. The high binding capacity, virus recovery and reduced pressure drop observed at residence times in the sub-minute range can potentially eliminate the need for prior concentration steps, thereby reducing the overall number of unit operations, process time and costs.

Optimization of fluid flow in membrane chromatography devices using computational fluid dynamic simulations

Flow uniformity within the device is critically important in membrane chromatography. Recent studies have shown that the design of the device has a significant impact on flow uniformity, and thereby on separation efficiency. The main premise of this work is that computational fluid dynamics (CFD) could serve as a fast and inexpensive tool for preliminary optimization of the design of a membrane chromatography device. CFD also helps in identifying factors that affect flow uniformity. In this paper, CFD is used to compare the fluidic attributes of conventional membrane chromatography devices such as the stacked disc and radial flow devices with those of more recently developed ones such as the different versions of the laterally-fed membrane chromatography (LFMC) device. These are compared based on pulse tracer solute dispersion, which is a useful metric for measuring flow uniformity, and is thereby a good predictor of chromatographic separation performance. The poor separation performance typically observed with conventional membrane chromatography devices could be attributed to the high degree of solute dispersion within these devices. CFD is then used to analyze the impact of factors such as membrane aspect ratio, and channel dimensions on the performance of z²-laterally-fed membrane chromatography (z²LFMC) devices. The results discussed in the paper demonstrate that CFD could indeed serve as a powerful optimization and performance prediction tool for membrane chromatography.

Reactive Green 19 dye-ligand immobilized on the aminated nanofiber membranes for efficient adsorption of lysozyme: Process development and optimization in batch and flow systems

The performance of lysozyme adsorption by the aminated nanofiber membrane immobilized with Reactive Green 19 (RG19) dyes was evaluated in batch and flow systems. The physicochemical properties of the dye-immobilized nanofiber membrane were characterized. The parameters of batch-mode adsorption of lysozyme (e.g., pH, initial dye concentration, and lysozyme concentration) were optimized using the Taguchi method. In a flow process, the factors influencing the dynamic binding performance for lysozyme adsorption in the chicken egg white (CEW) solution include immobilized dye concentration, adsorption pH value, feed flow rate, and feed CEW concentration. The impact of these operating conditions on the lysozyme purification process was investigated. Under optimal conditions, the recovery yield and purification factor of lysozyme achieved from the one-step adsorption process were 98.52% and 143 folds, respectively. The dye-affinity nanofiber membrane also did not exhibit any significant loss in its binding capacity and purification performance after five consecutive uses.

Scaling Up of Steric Exclusion Membrane Chromatography for Lentiviral Vector Purification

Lentiviral vectors (LVs) are widely used in clinical trials of gene and cell therapy. Low LV stability incentivizes constant development and the improvement of gentle process steps. Steric exclusion chromatography (SXC) has gained interest in the field of virus purification but scaling up has not yet been addressed. In this study, the scaling up of lentiviral vector purification by SXC with membrane modules was approached. Visualization of the LVs captured on the membrane during SXC showed predominant usage of the upper membrane layer. Furthermore, testing of different housing geometries showed a strong influence on the uniform usage of the membrane. The main use of the first membrane layer places a completely new requirement on the scaling of the process and the membrane modules. When transferring the SXC process to smaller or larger membrane modules, it became apparent that scaling of the flow rate is a critical factor that must be related to the membrane area of the first layer. Performing SXC at different scales demonstrated that a certain critical minimum surface area-dependent flow rate is necessary to achieve reproducible LV recoveries. With the presented scaling approach, we were able to purify 980 mL LVs with a recovery of 68%.

Double-sided plasmonic metasurface for simultaneous biomolecular separation and SERS detection

Porous membrane-based nanofiltration separation of small biomolecules is a widely used biotechnology for which size-based selectivity is a critical parameter of technological relevance. Efficient determination of size selectivity calls for an advanced detection method capable of performing sensitive, rapid, and on-membrane examination. Surface-enhanced Raman spectroscopy (SERS) is such a detection method that has been widely recognized as an ultrasensitive technique for trace-level detection with sensitivity down to the single-molecule level. In this work, we for the first time develop a double-sided hierarchical porous membrane-like plasmonic metasurface to realize high-selectivity bimolecular separation and simultaneous ultrasensitive SERS detection. This highly flexible device, consisting of subwavelength nanocone pairs surrounded by randomly orientated sub-5 nm nanogrooves, was prepared by combining customized "top-down" fabrication of conical nanopores in an ion-track registered polycarbonate membrane and self-assembly of nanogrooves on the membrane surface through physical vapor deposition. The unique tip-to-tip oriented conical nanopores in the device enables excellent size-based molecular selectivity; the hierarchical groove-pore structure supports a peculiar cascaded electromagnetic near-field enhancement mechanism, endowing the device with SERS-based molecular detection of ultrahigh sensitivity, uniformity, repeatability, and polarization independence. With such dual structural merits and performance enhancement, we demonstrate effective nanofiltration separation of small-sized adenine from big-sized ss-DNA and synergistic SERS determination of their species. We experimentally demonstrate an ultrasensitive detection of 4-mercaptopyridine down to 10 pM. Together with its unparalleled mechanical flexibility, this double-side-responsive plasmonic metasurface membrane can find great potential in real-world molecular filtration and detection under extremely complex working conditions.

Recent development and application of membrane chromatography

Membrane chromatography is mainly used for the separation and purification of proteins and biological macromolecules in the downstream processing process, also applications in sewage disposal. Membrane chromatography is recognized as an effective alternative to column chromatography because it significantly improves chromatography from affinity, hydrophobicity, and ion exchange; the development status of membrane chromatography in membrane matrix and membrane equipment is thoroughly discussed, and the applications of protein capture and intermediate purification, virus, monoclonal antibody purification, water treatment, and others are summarized. This review will provide value for the exploration and potential application of membrane chromatography.

Assessment of thermally stabilized electrospun poly(vinyl alcohol) materials as cell permeable membranes for a novel blood salvage device

The use of Intraoperative Cell Salvage (ICS) is currently limited in oncological surgeries, due to safety concerns associated with the ability of existing devices to successfully remove circulating tumour cells. In this work, we present the first stages towards the creation of an alternative platform to current cell savers, based on the extremely selective immunoaffinity membrane chromatography principle. Non-woven membranes were produced via electrospinning using poly(vinyl alcohol) (PVA), and further heat treated at 180 °C to prevent their dissolution in aqueous environments and preserve their fibrous morphology. The effects of the PVA degree of hydrolysis (DH) (98 % vs 99 %), method of electrospinning (needleless DC vs AC), and heat treatment duration (1-8 h) were investigated. All heat treated supports maintained their cytocompatibility, whilst tensile tests indicated that the 99 % hydrolysed DC electrospun mats were stronger compared to their 98 % DH counterparts. Although, and at the described conditions, AC electrospinning produced fibres with more than double the diameter compared to those from DC electrospinning, it was not chosen for subsequent experiments because it is still under development. Evidence of unimpeded passage of SY5Y neuroblastoma cells and undiluted defibrinated sheep's blood in flow-through filtration experiments confirmed the successful creation of 3D networks with minimum resistance to mass transfer and lack of non-specific cell binding to the base material, paving the way for the development of novel, highly selective ICS devices for tumour surgeries.

Negatively Charged Composite Nanofibrous Hydrogel Membranes for High-Performance Protein Adsorption

Nanofibrous materials are considered as promising candidates for fabricating high-efficiency chromatography media, which are urgently needed in protein pharmaceuticals purification and biological research, yet still face several bottlenecks. Herein, novel negatively charged composite nanofibrous hydrogel membranes (NHMs) are obtained by a facile combination of electrospinning and surface coating modification. The resulting NHMs exhibit controllable morphologies and chemical structures. Benefitting from the combined effect of the stable framework of silicon dioxide (SiO₂) nanofiber and the function layer of negatively charged hydrogel, as well as good pore connectivity among nanofibers, NHMs exhibit a high protein adsorption capacity of around 1000 mg g^-1, and are superior to the commercial cellulose fibrous adsorbent (Sartobind^®) and the reported nanofibrous membranous adsorbents. Moreover, due to their relatively stable physicochemical and mechanical properties, NHMs possess comprehensive adsorption performance, favorable resistance to acid and solvents, good selectivity, and excellent regenerability. The designed NHMs composite adsorbents are expected to supply a new protein chromatography platform for effective protein purification in biopharmaceuticals and biochemical reagents.

Studies of Protein Wastes Adsorption by Chitosan-Modified Nanofibers Decorated with Dye Wastes in Batch and Continuous Flow Processes: Potential Environmental Applications

In this study, reactive green 19 dye from wastewater was immobilized on the functionalized chitosan nanofiber membranes to treat soluble microbial proteins in biological wastewater. Polyacrylonitrile nanofiber membrane (PAN) was prepared by the electrospinning technique. After heat treatment, alkaline hydrolysis, and chemically grafted with chitosan to obtain modified chitosan nanofibers (P-COOH-CS), and finally immobilized with RG19 dye, dyed nanofibers were generated (P-COOH-CS-RG19). The synthesis of P-COOH-CS and P-COOH-CS-RG19 are novel materials for protein adsorption that are not deeply investigated currently, with each of the material functions based on their properties in significantly improving the adsorption efficiency. The nanofiber membrane shows good adsorption capacity and great recycling performance, while the application of chitosan and dye acts as the crosslinker in the nanofiber membrane and consists of various functional groups to enhance the adsorption of protein. The dyed nanofibers were applied for the batch adsorption of soluble protein (i.e., lysozyme), and the process parameters including chitosan’s molecular weight, coupling pH, chitosan concentration, dye pH, dye concentration, and lysozyme pH were studied. The results showed that the molecular weight of chitosan was 50 kDa, pH 5, concentration 0.5%, initial concentration of dye at 1 mg/mL dye and pH 12, lysozyme solution at 2 mg/mL at pH 8, and the maximum adsorption capacity was 1293.66 mg/g at a temperature of 318 K. Furthermore, thermodynamic, and kinetic studies suggested that the adsorption behavior of lysozyme followed the Langmuir adsorption isotherm model and the pseudo-second-order kinetic model. The optimal adsorption and desorption conditions based on batch experiments were directly applied to remove lysozyme in a continuous operation. This study demonstrated the potential of dyed nanofibers as an efficient adsorbent to remove approximately 100% of lysozyme from the simulated biological wastewater.

Use of the Dispersion Coefficient as the Sole Structural Parameter to Model Membrane Chromatography

The characterization and modelling of membrane chromatography processes require the axial dispersion coefficient as a relevant and effective intrinsic property of porous media, instead of arbitrary assumptions on pore size distribution. The dispersion coefficient can be easily measured by experiments completely independent of chromatographic tests. The paper presents the prediction of experimentally obtained breakthrough curves using B14-TRZ-Epoxy2 membranes as a test case; the mathematical model implemented is based on the use of the experimentally measured axial dispersion coefficient as an input parameter. Application of the model and its comparison with the data demonstrate that alternative ways of explaining the shape of breakthrough curves, based on unverified assumptions about the membrane pore size distribution, are not feasible and not effectively supported by experimental evidence. In contrast, the axial dispersion coefficient is the only measurable parameter that accounts for all the different contributions to the dispersion phenomenon that occurs in the membrane chromatography process, including the effects due to porous structure and pore size distribution. Therefore, mathematical models that rely on the mere assumption of pore size distribution, regardless of the role of the axial dispersion coefficient, are in fact arbitrary and ultimately misleading.

Membrane Chromatography and Fractionation of Proteins from Whey—A Review

Membrane chromatography (MC) is an emerging bioseparation technology combining the principles of membrane filtration and chromatography. In this process, one type of molecule is adsorbed in the stationary phase, whereas the other type of molecule is passed through the membrane pores without affecting the adsorbed molecule. In subsequent the step, the adsorbed molecule is recovered by an elution buffer with a unique ionic strength and pH. Functionalized microfiltration membranes are usually used in radial flow, axial flow, and lateral flow membrane modules in MC systems. In the MC process, the transport of a solute to a stationary phase is mainly achieved through convection and minimum pore diffusion. Therefore, mass transfer resistance and pressure drop become insignificant. Other characteristics of MC systems are a minimum clogging tendency in the stationary phase, the capability of operating with a high mobile phase flow rate, and the disposable (short term) application of stationary phase. The development and application of MC systems for the fractionation of individual proteins from whey for investigation and industrial-scale production are promising. A significant income from individual whey proteins together with the marketing of dairy foods may provide a new commercial outlook in dairy industry. In this review, information about the development of a MC system and its applications for the fractionation of individual protein from whey are presented in comprehensive manner.

Integrated autolysis, DNA hydrolysis and precipitation enables an improved bioprocess for Q-Griffithsin, a broad-spectrum antiviral and clinical-stage anti-COVID-19 candidate

Across the biomanufacturing industry, innovations are needed to improve efficiency and flexibility, especially in the face of challenges such as the COVID-19 pandemic. Here we report an improved bioprocess for Q-Griffithsin, a broad-spectrum antiviral currently in clinical trials for COVID-19. Q-Griffithsin is produced at high titer in E. coli and purified to anticipated clinical grade without conventional chromatography or the need for any fixed downstream equipment. The process is thus both low-cost and highly flexible, facilitating low sales prices and agile modifications of production capacity, two key features for pandemic response. The simplicity of this process is enabled by a novel unit operation that integrates cellular autolysis, autohydrolysis of nucleic acids, and contaminant precipitation, giving essentially complete removal of host cell DNA as well as reducing host cell proteins and endotoxin by 3.6 and 2.4 log10 units, respectively. This unit operation can be performed rapidly and in the fermentation vessel, such that Q-GRFT is obtained with 100% yield and > 99.9% purity immediately after fermentation and requires only a flow-through membrane chromatography step for further contaminant removal. Using this operation or variations of it may enable improved bioprocesses for a range of other high-value proteins in E. coli.

Clinical grade lentiviral vector purification and quality control requirements

Lentiviral vectors have been proven to be a powerful tool in gene therapies that includes the ability to perform long-term gene editing in both dividing and non-dividing cells. In order to meet the rising demand of clinical grade lentiviral vectors for future clinical trials and requirements by regulatory agencies, new methods and technologies were developed, including the rapid optimization of production and purification processes. However, gaps still exist in achieving ideal yields and recovery rates in large-scale manufacturing process steps. The downstream purification process is a critical step required to obtain sufficient quantity and high-quality lentiviral vectors products, which is challenged by the low stability of the LV particles and large production volumes associated with the manufacturing process. This review summarizes the most recent and promising technologies and enhancements used in the large-scale purification process step of LV manufacturing and aims to provide a significant contribution towards the achievement of providing sufficient quantity and quality of LVs in scalable processes. This article is protected by copyright. All rights reserved.

Cationic microcrystalline cellulose - Montmorillonite composite aerogel for preconcentration of inorganic anions from dairy wastewater

Development of efficient adsorbents to inorganic anions as a solid phase extraction (SPE) material is highly desirable for chromatographic analysis and pollution control. In this work we developed a new hybrid cationic microcrystalline cellulose aerogel composite. Cationic cetylpyridinium imbedded montmorillonite (CPC-MT) was uniformly entrapped in microcrystalline cellulose (MCC) to enhance anionic adsorption efficiency and mechanical stability. The developed CPC-MT@MCC aerogel was used as an SPE adsorbent for anions from dairy wastewater by coupling with ion-column chromatography. Further quaternized CPC-MT@MCC aerogel (CPC-MT@QMCC) showed unique low density (10.6 mg cm^-3), large specific surface area (320 m² g^-1), porosity 70%, 800 mg g^-1 nitrate adsorption capacity within 60 min and ease of elution in alkaline solutions. The CPC-MT@QMCC aerogel showed efficient regeneration and reuse performances for up to 10 cycles. More importantly, a dynamic binding efficiency of 710 mg g^-1 highlights its excellent performance for practical applications. 96% of nitrate anion from environmental manure wastewater samples were adsorbed with 98.7% recovery. A good linear relationship was obtained in the range of 0.01-10 mg L^-1 and the limits of detection was 0.5 mg L^-1 using CPC-MT@QMCC aerogel as a preconcentration column. The successful synthesis of such intriguing and economic CPC-MT@QMCC aerogel may provide a promising matrix for high-performance and high efficiency chromatographic media.

Integrated Autolysis, DNA Hydrolysis and Precipitation Enables an Improved Bioprocess for Q-Griffithsin, a Broad-Spectrum Antiviral and Clinical-Stage anti-COVID-19 Candidate

Across the biomanufacturing industry, innovations are needed to improve efficiency and flexibility, especially in the face of challenges such as the COVID-19 pandemic. Here we report an improved bioprocess for Q-Griffithsin, a broad-spectrum antiviral currently in clinical trials for COVID-19. Q-Griffithsin is produced at high titer in E. coli and purified to anticipated clinical grade without conventional chromatography or the need for any fixed downstream equipment. The process is thus both low-cost and highly flexible, facilitating low sales prices and agile modifications of production capacity, two key features for pandemic response. The simplicity of this process is enabled by a novel unit operation that integrates cellular autolysis, autohydrolysis of nucleic acids, and contaminant precipitation, giving essentially complete removal of host cell DNA as well as reducing host cell proteins and endotoxin by 3.6 and 2.4 log ₁₀ units, respectively. This unit operation can be performed rapidly and in the fermentation vessel, such that Q-GRFT is obtained with 100% yield and >99.9% purity immediately after fermentation and requires only a flow-through membrane chromatography step for further contaminant removal. Using this operation or variations of it may enable improved bioprocesses for a range of other high-value proteins in E. coli .

HIGHLIGHTS

Integrating autolysis, DNA hydrolysis and precipitation enables process simplificationAutolysis reduces endotoxin release and burden to purificationQ-Griffithsin recovered from fermentation vessel at >99.9% purity and 100% yieldQ-Griffithsin purified to anticipated clinical grade without conventional chromatographyThe resulting bioprocess is 100% disposables-compatible, scalable, and low-cost.

Streamlined process development procedure incorporating the selection of various stationary phase types established in a mAb aggregate reduction study with different mixed mode ligands

In biopharmaceutical process development time, cost and reliability are the relevant keywords. During the development of chromatographic processes these targets are challenged by many possible scaffolds, ligands and process parameters. The common response to this diversity is the establishment of platform processes in the development of chromatographic unit operations. However, while developing a platform library to simplify and accelerate chromatographic processes, the potential combination of scaffold, ligands and process parameters need to be characterized. This challenge is addressed in a case study on novel mixed mode (MM) adsorber for the removal of monoclonal antibody (mAb) aggregates. We propose a rigorous strategy to reduce the various experimental design space resulting from possible combinations in scaffolds, backbones and ligands. This strategy is based on theoretical considerations, identification of adsorber selectivity and capacity for the identification of a suitable membrane system. For this system, each potential MM membrane adsorber (MA) candidate is investigated in its high molecular weight species (HMWS) reduction potential for a given mAb feed stream and referenced to the performance of Capto™ Adhere. The introduced strategy can reduce the developmental effort in an early stage from three to two possible stationary phases. Thereafter, initial examinations at different ionic capacities enlighten one favorable stationary phase. Finalizing the development strategy procedure by studying five different MM ligands by HTS and confirming the study with a 2-3 MV higher dynamic breakthrough capacity in benchtop experiments and provides an insight in the benefits of a living process platform library. This article is protected by copyright. All rights reserved.

Kinetic and Thermodynamic Studies of Lysozyme Adsorption on Cibacron Blue F3GA Dye-Ligand Immobilized on Aminated Nanofiber Membrane

The polyacrylonitrile (PAN) nanofiber membrane was prepared by the electrospinning technique. The nitrile group on the PAN nanofiber surface was oxidized to carboxyl group by alkaline hydrolysis. The carboxylic group on the membrane surface was then converted to dye affinity membrane through reaction with ethylenediamine (EDA) and Cibacron Blue F3GA, sequentially. The adsorption characteristics of lysozyme onto the dye ligand affinity nanofiber membrane (namely P-EDA-Dye) were investigated under various conditions (e.g., adsorption pH, EDA coupling concentration, lysozyme concentration, ionic strength, and temperature). Optimum experimental parameters were determined to be pH 7.5, a coupling concentration of EDA 40 μmol/mL, and an immobilization density of dye 267.19 mg/g membrane. To understand the mechanism of adsorption and possible rate controlling steps, a pseudo first-order, a pseudo second-order, and the Elovich models were first used to describe the experimental kinetic data. Equilibrium isotherms for the adsorption of lysozyme onto P-EDA-Dye nanofiber membrane were determined experimentally in this work. Our kinetic analysis on the adsorption of lysozyme onto P-EDA-Dye nanofiber membranes revealed that the pseudo second-order rate equation was favorable. The experimental data were satisfactorily fitted by the Langmuir isotherm model, and the thermodynamic parameters including the free energy change, enthalpy change, and entropy change of adsorption were also determined accordingly. Our results indicated that the free energy change had a negative value, suggesting that the adsorption process occurred spontaneously. Moreover, after five cycles of reuse, P-EDA-Dye nanofiber membranes still showed promising efficiency of lysozyme adsorption.

Highly Efficient Purification of Recombinant VSV-∆G-Spike Vaccine against SARS-CoV-2 by Flow-Through Chromatography

This study reports a highly efficient, rapid one-step purification process for the production of the recombinant vesicular stomatitis virus-based vaccine, rVSV-∆G-spike (rVSV-S), recently developed by the Israel Institute for Biological Research (IIBR) for the prevention of COVID-19. Several purification strategies are evaluated using a variety of chromatography methods, including membrane adsorbers and packed-bed ion-exchange chromatography. Cell harvest is initially treated with endonuclease, clarified, and further concentrated by ultrafiltration before chromatography purification. The use of anion-exchange chromatography in all forms results in strong binding of the virus to the media, necessitating a high salt concentration for elution. The large virus and spike protein binds very strongly to the high surface area of the membrane adsorbents, resulting in poor virus recovery (<15%), while the use of packed-bed chromatography, where the surface area is smaller, achieves better recovery (up to 33%). Finally, a highly efficient chromatography purification process with Capto^TM Core 700 resin, which does not require binding and the elution of the virus, is described. rVSV-S cannot enter the inner pores of the resin and is collected in the flow-through eluent. Purification of the rVSV-S virus with Capto^TM Core 700 resulted in viral infectivity above 85% for this step, with the efficient removal of host cell proteins, consistent with regulatory requirements. Similar results were obtained without an initial ultrafiltration step.

Orthogonal pre-use and post-use efficiency testing for single-use anion exchange chromatography

Three efficiency tests for single-use AEX chromatography devices have been developed and applied to six capsule formats of a new, salt tolerant, single-use AEX product. All the tests have been designed to be performed with simple equipment and common reagents. By performing each of the three tests on undamaged capsules and capsules intentionally damaged with small defects, in tandem with Phi-X174 challenges in a high-salt buffer, relationships between test results and viral clearance have been obtained. A pre-use pressure-based installation verification test is simply performed during equilibration of the device and effective at identifying gross bypass defects, for example, due to internal seal breakage. Passing outcomes of a post-use installation validation bubble point test are associated with ≥ 5 log reduction value (LRV) of viral clearance. A new, non-destructive, pre-use AEX capacity test involves challenging the device with chloride ions and is orthogonal to the other two tests in that it can detect chemical defects, as well as mechanical ones. Passing outcomes of this test correspond to > 2 LRV viral clearance and provide in situ assurance of the expected AEX dynamic capacity prior to use. Selection of a pair of pre-use and post-use tests can provide robust risk reduction with respect to viral clearance by single-use AEX devices in biopharmaceutical purifications.

Purification of Modified Therapeutic Proteins Available on the Market: An Analysis of Chromatography-Based Strategies

Proteins, which have inherent biorecognition properties, have long been used as therapeutic agents for the treatment of a wide variety of clinical indications. Protein modification through covalent attachment to different moieties improves the therapeutic's pharmacokinetic properties, affinity, stability, confers protection against proteolytic degradation, and increases circulation half-life. Nowadays, several modified therapeutic proteins, including PEGylated, Fc-fused, lipidated, albumin-fused, and glycosylated proteins have obtained regulatory approval for commercialization. During its manufacturing, the purification steps of the therapeutic agent are decisive to ensure the quality, effectiveness, potency, and safety of the final product. Due to the robustness, selectivity, and high resolution of chromatographic methods, these are recognized as the gold standard in the downstream processing of therapeutic proteins. Moreover, depending on the modification strategy, the protein will suffer different physicochemical changes, which must be considered to define a purification approach. This review aims to deeply analyze the purification methods employed for modified therapeutic proteins that are currently available on the market, to understand why the selected strategies were successful. Emphasis is placed on chromatographic methods since they govern the purification processes within the pharmaceutical industry. Furthermore, to discuss how the modification type strongly influences the purification strategy, the purification processes of three different modified versions of coagulation factor IX are contrasted.

Planar chromatography and immunodetection of hydrocarbons on polyvinylidene difluoride membranes

Fast, cheap, and simple separation of lipids and hydrocarbons can currently be achieved using thin-layer chromatography. Here, we describe an alternative planar chromatographic method using polyvinylidene difluoride membranes as the stationary phase. The procedure has the same advantages of thin-layer chromatography over other expensive and time-consuming techniques, such as high-performance liquid chromatography or gas chromatography. Polyvinylidene difluoride membranes, however, also provide an immediate support for analyte development via immunodetection, are easy to manipulate, and potentially increase the performance of other detection methods. We show that polyvinylidene difluoride membranes are compatible with a variety of solvents that can migrate by capillarity and redistribute analytes between the membrane and the solvent according to their relative affinities, providing a chromatographic separation. We directly test the developed membranes by immunoblotting using anti-squalene antibodies that cross-react with acyclic isoprenoids. Separations of crude oils and plant extracts under different solvent conditions show the potential to resolve hydrocarbon group types and also to provide characteristic fingerprints of plant pigments and squalene degradation products. Polyvinylidene difluoride membranes prove useful as a stationary phase for planar chromatography and for the subsequent immunodetection of the separated compounds, providing a new and simple chromatographic technique to analyze lipids and hydrocarbons.

Critical Assessment of Purification and Analytical Technologies for Enveloped Viral Vector and Vaccine Processing and Their Current Limitations in Resolving Co-Expressed Extracellular Vesicles

Viral vectors and viral vaccines are invaluable tools in prevention and treatment of diseases. Many infectious diseases are controlled using vaccines designed from subunits or whole viral structures, whereas other genetic diseases and cancers are being treated by viruses used as vehicles for delivering genetic material in gene therapy or as therapeutic agents in virotherapy protocols. Viral vectors and vaccines are produced in different platforms, from traditional embryonated chicken eggs to more advanced cell cultures. All these expression systems, like most cells and cellular tissues, are known to spontaneously release extracellular vesicles (EVs). EVs share similar sizes, biophysical characteristics and even biogenesis pathways with enveloped viruses, which are currently used as key ingredients in a number of viral vectors and licensed vaccine products. Herein, we review distinctive features and similarities between EVs and enveloped viruses as we revisit the downstream processing steps and analytical technologies currently implemented to produce and document viral vector and vaccine products. Within a context of well-established viral vector and vaccine safety profiles, this review provides insights on the likely presence of EVs in the final formulation of enveloped virus products and discusses the potential to further resolve and document these components.

Iminodiacetic Acid (IDA) Cation-Exchange Nonwoven Membranes for Efficient Capture of Antibodies and Antibody Fragments

There is strong need to reduce the manufacturing costs and increase the downstream purification efficiency of high-value therapeutic monoclonal antibodies (mAbs). This paper explores the performance of a weak cation-exchange membrane based on the coupling of IDA to poly(butylene terephthalate) (PBT) nonwoven fabrics. Uniform and conformal layers of poly(glycidyl methacrylate) (GMA) were first grafted to the surface of the nonwovens. Then IDA was coupled to the polyGMA layers under optimized conditions, resulting in membranes with very high permeability and binding capacity. This resulted in IgG dynamic binding capacities at very short residence times (0.1–2.0 min) that are much higher than those achieved by the best cation-exchange resins. Similar results were obtained in the purification of a single-chain (scFv) antibody fragment. As is customary with membrane systems, the dynamic binding capacities did not change significantly over a wide range of residence times. Finally, the excellent separation efficiency and potential reusability of the membrane were confirmed by five consecutive cycles of mAb capture from its cell culture harvest. The present work provides significant evidence that this weak cation-exchange nonwoven fabric platform might be a suitable alternative to packed resin chromatography for low-cost, higher productivity manufacturing of therapeutic mAbs and antibody fragments.

Fast and high-resolution purification of a PEGylated protein using a z2 laterally-fed membrane chromatography device

PEGylated proteins comprise a class of value-added biopharmaceuticals. High-resolution separation techniques are required for the purification of these molecules. In this study, we discuss the application of a newly developed z² laterally-fed membrane chromatography (or z²LFMC) device for carrying out high-resolution purification of a PEGylated protein drug. The device used in the current study contained a stack of anion exchange (Q) membranes. The membrane bed-height of this z²LFMC device being small, it could be operated at very high flow rates, at relatively low back pressures. The primary goal was to speedily and efficiently separate a mono-PEGylated protein from impurities present in the PEGylation reaction mixture. A resin-based anion exchange column having the same ligand and bed-volume was used as the control device. The purification performance of the z²LFMC device and the control column were compared terms of resolution, recovery and purity. The z²LFMC device outperformed the control column in terms of every metric compared in this study. Higher purity (85.4% as opposed to 77.9%) and higher recovery (28% greater) of the target mono-PEGylated protein were obtained using the z²LFMC device at 20-time higher speed. These results clearly demonstrate that the z²LFMC device could be a faster and more efficient alternative to resin-based columns for purification of biopharmaceuticals.

Adsorption and purification performance of lysozyme from chicken egg white using ion exchange nanofiber membrane modified by ethylene diamine and bromoacetic acid

A high-performance polyacid ion exchange (IEX) nanofiber membrane was used in membrane chromatography for the recovery of lysozyme from chicken egg white (CEW). The polyacid IEX nanofiber membrane (P-BrA) was prepared by the functionalization of polyacrylonitrile (PAN) nanofiber membrane with ethylene diamine (EDA) and bromoacetic acid (BrA). The adsorption performance of P-BrA was evaluated under various operating conditions using Pall filter holder. The results showed that optimal conditions of IEX membrane chromatography for lysozyme adsorption were 10% (w/v) of CEW, pH 9 and 0.1 mL/min. The purification factor and yield of lysozyme were 402 and 91%, respectively. The adsorption process was further scaled up to a larger loading volume, and the purification performance was found to be consistent. Furthermore, the regeneration of IEX nanofiber membrane was achieved under mild conditions. The adsorption process was repeated for five times and the adsorption capacity of adsorber was found to be unaffected.

Developments and opportunities in continuous biopharmaceutical manufacturing

Today’s biologics manufacturing practices incur high costs to the drug makers, which can contribute to high prices for patients. Timely investment in the development and implementation of continuous biomanufacturing can increase the production of consistent-quality drugs at a lower cost and a faster pace, to meet growing demand. Efficient use of equipment, manufacturing footprint, and labor also offer the potential to improve drug accessibility. Although technological efforts enabling continuous biomanufacturing have commenced, challenges remain in the integration, monitoring, and control of traditionally segmented unit operations. Here, we discuss recent developments supporting the implementation of continuous biomanufacturing, along with their benefits.

Nonwoven Ion-Exchange Membranes with High Protein Binding Capacity for Bioseparations

This study presents the preparation and characterization of UV-grafted polybutylene terepthalate (PBT) ion exchange nonwoven membranes for chromatographic purification of biomolecules. The PBT nonwoven was functionalized with sulfonate and secondary amine for cation and anion exchange (CEX and AEX), respectively. The anion exchange membrane showed an equilibrium static binding capacity of 1300 mg BSA/g of membrane, while the cationic membranes achieved a maximum equilibrium binding capacity of over 700 mg hIgG/g of membrane. The CEX and AEX membranes resulted in dynamic binding capacities under flow conditions, with a residence time of 0.1 min, of 200 mg hIgG/mL of membrane and 55 mg BSA/mL of membrane, respectively. The selectivity of the PBT-CEX membranes was demonstrated by purifying antibodies and antibody fragments (hIgG and scFv) from CHO cell culture supernatants in a bind-an-elute mode. The purity of the eluted samples exceeded 97%, with good log removal values (LRV) for both host cell proteins (HCPs) and DNA. The PBT-AEX nonwoven membranes exhibited a DNA LRV of 2.6 from hIgG solutions in a flow-through mode with little loss of product. These results indicate that these membranes have significant potential for use in downstream purification of biologics.

Lentiviral Vector Bioprocessing

Lentiviral vectors (LVs) are potent tools for the delivery of genes of interest into mammalian cells and are now commonly utilised within the growing field of cell and gene therapy for the treatment of monogenic diseases and adoptive therapies such as chimeric antigen T-cell (CAR-T) therapy. This is a comprehensive review of the individual bioprocess operations employed in LV production. We highlight the role of envelope proteins in vector design as well as their impact on the bioprocessing of lentiviral vectors. An overview of the current state of these operations provides opportunities for bioprocess discovery and improvement with emphasis on the considerations for optimal and scalable processing of LV during development and clinical production. Upstream culture for LV generation is described with comparisons on the different transfection methods and various bioreactors for suspension and adherent producer cell cultivation. The purification of LV is examined, evaluating different sequences of downstream process operations for both small- and large-scale production requirements. For scalable operations, a key focus is the development in chromatographic purification in addition to an in-depth examination of the application of tangential flow filtration. A summary of vector quantification and characterisation assays is also presented. Finally, the assessment of the whole bioprocess for LV production is discussed to benefit from the broader understanding of potential interactions of the different process options. This review is aimed to assist in the achievement of high quality, high concentration lentiviral vectors from robust and scalable processes.