Analytical

Accelerating Process Development Through Flexible Automated Workflows

Synthace began as a bioprocess optimization company in 2011, spun out of University College, London. The company worked on multifactorial approaches with 15–30 factors simultaneously instead of seven or eight. The work investigated genetic strain engineering factors alongside process parameters, defining deep interactions between the way strains were designed and the way they were treated in bioprocesses. Those complex experiments gave unique insight into the complexities of biological processes, but they were exceptionally taxing to plan and carryout manually. Automation…

Model Predictive Control for Bioprocess Forecasting and Optimization

Automation hierarchy in bioprocess manufacturing consists of a regulatory layer, process analytics technology (PAT), and (potentially) a top-level model-predictive or supervisory layer. The regulatory layer is responsible for keeping typical process measurements such as temperature, pressure, flows, and pH on target. In some cases, spectral instrumentation in combination with multivariate analysis (MVA) can be configured to measure parameters such as glucose concentration. A cascade control structure can be set up when the nutrient flow setpoint is adjusted to maintain the…

CO2, O2, and Biomass Monitoring in Escherichia coli Shake Flask Culture: Following Glucose–Glycerin Diauxie Online

Carbon dioxide (CO2) is an important parameter in microbial cultures because it can inhibit or stimulate growth under certain conditions. In our experiment, we monitored Escherichia coli diauxie growth phases online and focused on dissolved CO2 (dCO2) and oxygen readings. We assessed diauxic growth in medium containing glycerin and glucose online with the SFR vario system (from PreSens), which optically measures oxygen, pH, and biomass in an Erlenmeyer flask. The shake flask contained an oxygen sensor spot and an optical…

Antibody–Drug Conjugates: Fast-Track Development from Gene to Product

In the fight against cancer, antibody–drug conjugates (ADCs) represent an increasingly important therapeutic approach. These biopharmaceuticals are designed to maximize the therapeutic index of cytotoxic small-molecule drugs through their selective delivery to tumor cells while leaving normal, healthy cells untouched. Structurally, an ADC is a monoclonal antibody (MAb) conjugated by a chemical linker to a potent cytotoxic drug. Conceptually, the MAb serves as the delivery component, targeting a specific tumor antigen that ideally is not expressed (or is expressed at…

Antibody Higher Order Structure Stability: Polymorphism Revealed By Protein Conformational Array

For protein therapeutics and other biologics, the importance of the molecule’s structure to its efficacy and safety is well established (1–5). In particular, their tertiary and quaternary structures play very important roles in product quality and have been monitored extensively in comparability studies (6–12). However, because of both the large molecular size and rotational property of amino acid α carbons, a protein can assume an enormous number of different conformations (13). For antibody-based biologics such as monoclonal antibodies (MAbs), fusion…

A Stirred, Single-Use, Small-Scale Process Development System: Evaluation for Microbial Cultivation

Mammalian and microbial protein production platforms have been used for over 30 years to produce a number of successful biologic drugs, including monoclonal antibodies (MAbs), recombinant proteins, and therapeutic enzymes (1). Most biologics are produced by mammalian cell lines, with Chinese hamster ovary (CHO) cells being the most widely used. However, microbial cells also are used to express recombinant therapeutic proteins, and almost 30% of currently approved biologics are produced by Escherichia coli bacteria (2). With worldwide biologics sales >56…

Particulate Contamination in Single-Use Systems: Challenges of Detection, Measurement, and Continuous Improvement

Patients receiving particulate contamination through parenteral delivery of biopharmaceuticals presents a significant potential health risk. However, the severity of that risk often is unclear. It depends on the route of administration, dosage volume administered, particle properties and amount received, and the ultimate fate of particles within a patient’s body (1). The appearance of particulate contamination also can be a visible indicator of product quality. Consequently, when such contamination is discovered within biopharmaceutical manufacturing operations, often it triggers costly investigations and…

Recent Advances in Endotoxin Removal: An Upgrade to a Traditional Method and a New Adsorption Chemistry

Endotoxin contamination has been the bane of the bioprocessing industry since its inception. Endotoxins are everywhere: They are toxic and/or interfere with every type of therapeutic, diagnostic, and research product; they are indestructible within the limits of product tolerance; and they are difficult to remove (1–4). Beyond that, they interact with various biological species in ways that prevent accurate measurement (5, 6). Managing these issues has been a focus of the industry for at least half a century, yet it…

Viral Vector Particle Integrity and Purity Analyses in Early Process Development

Gene therapy is the transfer of genetic material to a patient’s cells to achieve a therapeutic effect. Therapeutic DNA typically is delivered using a viral vector system, and adenoviruses have been used for this purpose for over 20 years (1–3). Within the past 10 years or so, lentiviruses have shown promise in clinical trials (1–3), and adenoassociated viruses (AAVs) have been used in the first approved gene therapies in the Western world (4). The number of gene therapy applications based…

Development of a Host-Cell Protein Platform Assay for a Chinese Hamster Ovary Cell Line

The Chinese hamster ovary (CHO) cell line is the most prevalent biopharmaceutical expression system and has been proven safe for commercial production of protein therapeutics (1). However, even after multiple purification steps, biopharmaceuticals contain residual host-cell protein (HCP) impurities that pose a potential safety risk to patients (2). Health authorities demand close monitoring of HCP impurities and require sensitive analytical methods with high coverage: the ability to detect a broad range of HCP impurities (3, 4). Polyclonal sandwich immunoassays are…