Separation/Purification

Is Continuous Downstream Processing Becoming a Reality?

Over the past 30 years, several biopharmaceuticals have been produced by continuous cell culture processes run in a chemostat or perfusion mode. In most cases, no alternative was available to produce certain unstable molecules (1). However, downstream processing is and has remained a step-by-step batch operation. Continuous processing generally requires more process knowledge, equipment, and technological advances than do batch processes. With the maturity of bioprocessing and increasing awareness of manufacturing costs, companies are focusing on developing continuous downstream processing…

Scalable Purification of Viral Vectors for Gene Therapy: An Appraisal of Downstream Processing Approaches

Gene therapy is the transfer of genetic material to a patient’s cells to achieve a therapeutic effect. Therapeutic DNA is largely delivered using viral vector systems based on adenoviruses (Ad), adenoassociated viruses (AAV), and lentiviruses (LV). With the application of such viral vectors as clinical therapeutics growing, scalable commercial processes (particularly for purification) are being investigated and optimized to best ensure that critical quality attributes (CQAs) are retained. Herein we review viral vector purification techniques and the effect of different…

Downstream Disposables: The Latest Single-Use Solutions for Downstream Processing

Downstream processing has been considered a “bottleneck” in the manufacture of protein biotherapeutics ever since cell culture engineers began dramatically improving production efficiencies around the turn of the century. And as single-use technologies have grown in importance and acceptance, offering more solutions every year, their biggest challenges too have been in the separation, purification, and processing that follows product expression in cell culture. Many of the technologies familiar to process engineers — e.g., centrifugation and chromatography — present technical and…

Single-Use Depth Filters: Application in Clarifying Industrial Cell Cultures

For current process development phases, many biomanufacturers’ attention is directed increasingly to the first unit operation in downstream processing, which is the removal of cells and cell debris from culture broth and clarification of supernatant containing a biopharmaceutical product. Given the high cell densities achievable with both mammalian and microbial cell culture processes, primary recovery can be a significant challenge. The current trend in cell culture is to increase product titers with enriched culture media, improved cell productivity, and increased…

Membrane-Based Clarification of Polysaccharide Vaccines

Polysaccharide vaccines are essential for protection against infectious diseases, which remain an alarming cause of mortality. The first glycoconjugate vaccine for use in humans — a Haemophilus influenzae type b (Hib) conjugate — was licensed in the United States in 1987. This vaccine successfully reduced the incidence of invasive Hib disease in childhood and led to the further development of conjugate vaccines designed to prevent infection by other encapsulated bacteria (1). Polysaccharides are relatively complex carbohydrates made up of many…

Special Report: A Strategy for Cost-Effective Capture Using Agarose-Based Protein A Resins

It is well recognized that the cost of Protein A resins is substantial. If a developmental monoclonal antibody (MAb) makes it to marketing approval and manufacturing, the high cost of purification using a Protein A resin is amortized over a large number of purification cycles, and the contribution to cost of goods is reduced to acceptable levels. However, a high percentage of clinical projects will fail, and the Protein A resin will be used only for a small number of…

Innovative Downstream Purification Solutions for Viral Vectors: Enabling Platform Approaches to Advance Gene Therapies

Over the past decade, gene therapy applications and their importance in the biopharmaceutical industry have been increasing. Gene therapies promise versatile treatment options that could revolutionize and transform medicine. As treatment modalities, they offer the possibility of long-term and potentially curative benefits to patients with genetic or acquired diseases. Gene therapies are designed to treat disease by delivering genetic material that encodes a protein with a therapeutic effect into a patient’s cells. It can be used to replace a missing…

Viral Clearance in Antibody Purification Using Tentacle Ion Exchangers

Manufacturers strive toward cost-effective purification of target molecules and a high level of confidence that their biologics are safe and not compromised by the presence of endogenous retrovirus-like particles or adventitious viruses (1). Reliable reduction of viral particles throughout downstream purification processes must be ensured through different techniques such as chemical treatment, filtration, and chromatography. Common monoclonal antibody (MAb) purification schemes use both cation- and anion-exchange chromatography steps (CEX, AEX). Although CEX (to remove product- and process-related impurities) is not…

Development of a High-Performance, Integrated, and Disposable Clarification Solution for Continuous Bioprocessing

Current bioprocesses combine fed-batch cell culture with batch-wise downstream processing steps. To achieve integrated upstream and downstream continuous manufacturing, the industry has been in need of a continuous cell separation and clarification solution for bioprocess fluids from bioreactors. The Cadence Acoustic Separator from Pall Life Sciences provides this solution, with continuous first-stage clarification without the need for filter media in a scalable, single-use format with no negative impact on product attributes. The Cadence Acoustic Separator delivers cost and time savings…

Optimization and Scale-Up of HCIC-Based MAb Purification Processes, Part 2

In multistep schemes, hydrophobic charge-induction chromatography (HCIC) has been shown to contribute effectively to clearance of Chinese hamster ovary (CHO) host-cell proteins (CHOPs), DNA, and viruses. When used for capture chromatography, HCIC can provide better aggregate clearance than protein A sorbents can. Chen et al. enhanced clearance of aggregates, CHOPs, and product- related impurities by controlling HCIC based on both pH and the presence of binding-promoting salt in the wash and elution buffers used (1). Taken together with our findings…