The safety of biological products (biologics) derived from in vitro cultured cell lines of animal origin is dependent both on clinical studies to evaluate efficacy, and a matrix of controls throughout the manufacturing process to assure consistency, quality, and safety of the marketed product for human use. One major area of concern is virus safety. Through the combination of: (A) careful selection of raw materials; (B) testing of process intermediates; and (C) virus clearance evaluations of the individual steps in the manufacturing process; biologics manufacturers can demonstrate that their products are free from detectable adventitious and endogenous viruses. Comprehensive regulatory guidance suggests approaches for virus testing of biologics at early and later stages of clinical development and, although some countries have specific requirements, many of these approaches are harmonized worldwide. In general, regulatory authorities expect purification processes to include multiple steps with complementary, or orthogonal, methods for virus reduction including inactivation and separation or removal. Each step in the process may be more or less effective for reducing levels of different test viruses, and therefore selection of the appropriate panel of test viruses for the specific product is critical for viral clearance studies…
Tag: <span>cell culture</span>
The licensing of recombinant vaccines produced using the baculovirus expression vector system (BEVS) has cleared the way for the production of a variety of biopharmaceuticals produced using this technology. Obtaining accurate estimates of both total and infectious baculovirus titer in upstream and downstream bioprocess fluids is one of many process controls that will need to be addressed during the development phase of a product’s lifecycle. Traditional plaque-titer methods require 5–7 days of incubation in order to reveal plaques that may be enumerated, and is further complicated by plaques created by multiple viruses that may be scored as a single plaque, thereby lowering the titer estimate. Titer assays based on polymerase chain reaction (PCR) have been developed, but they measure the presence of baculovirus genes, not virus particles. This often results in titers one or two logs higher than the actual titer. Immunoassays correlate with host cell infection and virus replication, but they too can be time-consuming and difficult to interpret. Our goal was to identify a method that would provide estimates of both total and infectious virus particles in as close to real-time as possible. We have evaluated the ViroCyt Virus Counter over the course of three years and have found it to provide accurate and reproducible estimates of both titer types in as little as 30 minutes. We have created an algorithm that converts total virus particle counts into estimates of infectious titer and tested these values in virus amplifications. The Virus Counter method of titer determination has also been used to track the quantity of virus particles in the culture supernatant of stirred-tank bioreactors infected with standard baculovirus stocks and with baculovirus-infected insect cells (BIIC)…
The trend for increased vaccine production is being driven by the requirement to produce affordable prophylactic vaccines for use in emerging markets, and also for newer types of therapeutic vaccines to treat an ever-increasing array of diseases such as cancer. These drivers, coupled with the current need to produce vaccines rapidly for pandemic threats and seasonal influenza prevention, has lead to the investigation of rapid method development for optimising the scale-up of cGMP-compliant manufacturing processes…
Mammalian cell culture processes require an in depth understanding of inputs and outputs in order to maximize productivity, efficiency, and product quality. Daily monitoring of essential metabolites, nutrients, and protein titer using at-line analyzers are the building blocks of drug manufacturing process development and characterization. In order to better understand how these instruments perform, a comparative analysis was conducted using two different classes of metabolicsensing technologies, membrane-based technology (MBT) and absorption photometric-based technology (APBT). Four commercially available instruments were examined using various samples and maintenance conditions in order to emphasize the following testing criteria: specificity, linearity, range, accuracy, and precision. Samples included standard solutions with known metabolite concentrations, cell culture supernatant, and supernatant liquid spiked with additional metabolite solutions. The results from our testing indicated that the photometric analyzers yielded more accurate and consistent results than the membrane-based analyzers and were easier and less time-consuming to maintain. Ultimately, these studies summarized the capabilities and limitations for both types of analyzers and provide a critical summary for instruments used in everyday bioprocess monitoring…
Cells cultured in 2D can differ in terms of both physiology and cellular responses compared with cells in vivo. This has led to a surge in the popularity of using 3D culture techniques as mounting evidence suggests that culturing cells in 3D is more representative of the in vivo environment, even to the extent that the gene expression profiles of cells from 3D cultures more accurately reflect clinical expression profiles than those observed in 2D cultures. 3D culture offers the potential for more accurate models of drug delivery and efficacy, as well as numerous clinical and research applications, and is becoming increasingly capable of integrating into high-throughput activities. Spheroids, or sphere cultures, have become an especially exciting area of 3D in vitro culture due to their great potential for use in studies that investigate growth and function of both malignant and normal tissues. These sphere cultures have contributed considerably to our knowledge of cellular responses thanks to the accuracy with which they reflect the in vivo system.
Safety is typically viewed, perhaps unconsciously, as the result of a collection of factors, conditions, or behaviors. For example, consider “safety” in the context of personal, financial, or travel. With each, safety is defined as a set of component risks that have been managed to satisfactory levels for a particular situation. The same is true for product safety and risk, whether it be for raw materials or finished goods. The “safe” use of fetal bovine serum (FBS) is achieved by the management of controllable risks to a level that is acceptable for each particular application. For example, risk reduction requirements for research applications are not as stringent as for diagnostic, therapeutic, or manufacturing applications. Each end-user must decide on the level of risk reduction that is appropriate for their application…
For over 80 years, fetal bovine serum (FBS) and other animal-derived materials have been widely used in the production of vaccines, and more recently, biotherapeutics, for both human and animal applications. Ever since FBS was initially developed as a cell culture reagent, there have been efforts made to avoid the use of this critical commodity. The International Serum Industry Association (ISIA) recognizes the requirement for robust risk assessment and management, and has several ongoing programs designed to help mitigate the risk of using animal-derived materials. This article will provide an outline of the state of the industry and of these programs…
The treatment of animal serum by gamma irradiation, for the purpose of mitigating the risk of introducing a pathogen (virus, mollicute, or other microbe) into a cell culture, is a process that has been executed (and perhaps understood) primarily by irradiation contractors utilized by serum manufacturers. The selection of appropriate exposure conditions and irradiation doses is driven by a number of critical factors including: (1) the validation and control of the irradiation process itself; (2) the efficacy of the applied irradiation dose range for inactivating pathogens of interest; (3) determination and control of critical process attributes; (4) the potential impacts of these irradiation dose levels on the serum being irradiated; and finally, (5) the potential impact of irradiated serum on the medicinal product and the associated manufacturing process where serum is ultimately used. In order to increase awareness of these topics throughout the cell culture community, we have addressed these critical factors in the current review…
Biologics Biologics Production Bioreactor Scale-Up Cell & Gene Therapy Cell Lines Fed-Batch Bioreactor Process HEK293 Mammalian Cell Culture Manufacturing Regulatory Viral Reference Materials Viral Vectors
abattoir albumin animal serum animal-derived materials antibody biomedical research blood-derived products calf serum calicivirus cell culture cell medium challenge virus design of efficacy dose mapping fbs fetal bovine serum gamma irradiation heat inactivation isia kgy kilogray microbes mollicute nbcs pathogen reduction product management risk mitigation serum product serum risks spiked serum therapeutic proteins traceability viral reduction whole blood
This article serves as an introduction to a series of papers that are being authored under the sponsorship of the International Serum Industry Association with the purpose of establishing best practices for processes employed in the gamma irradiation of animal serum. It is comprised of a discussion about the role of serum in cell culture and the management of the associated risks. Additional articles in the series will address a number of topics of interest to the cell culture community, including, but not limited to: (1) performance of absorbed dose mapping for irradiators; (2) validation of the efficacy of pathogen reduction during gamma irradiation of animal serum; (3) comparability evaluation of irradiated serum; (4) product management throughout the irradiation process; and (5) ensuring a quality outcome when using gamma irradiation. The intent of the series is to increase awareness of the scientific community regarding the conduct of gamma irradiation and the strengths and limitations of this serum treatment approach for achieving the goals of adventitious agent risk mitigation.
Biologics Biologics Production Bioreactor Scale-Up Cell & Gene Therapy Cell Lines Fed-Batch Bioreactor Process HEK293 Mammalian Cell Culture Manufacturing Regulatory Viral Reference Materials Viral Vectors
abattoir albumin animal serum animal-derived materials biomedical research blood-derived products calf serum cell culture cell medium dose mapping fbs fetal bovine serum gamma irradiation heat inactivation isia nbcs pathogen reduction product management risk mitigation serum risks therapeutic proteins traceability whole blood
With increasing time pressures to move biological therapeutics into the clinic, bioprocessing development studies have to be limited. Currently, core studies typically involve the use of shake flasks and benchtop bioreactors to select the most productive clones, optimum media, and bioprocessing conditions. The capacity for using benchtop bioreactors is especially limited as it is resource-intensive and has high capital equipment and infrastructure costs. Consequently, scientists frequently cannot perform full design-of-experiments (DoE) and are generally only able to take one or two of their most promising clones forward for partial DoE runs in benchtop bioreactors.