Gamma irradiation is a well-established process for reducing or eliminating the bacterial and viral load in medical devices, biologics, and other products such as animal sera. This process can lead to alterations in both the materials being treated and the product containers in use. High-energy radiation produces ionization and excitation in materials, generating energy-rich ions which undergo dissociation, abstraction, and additional reactions in a sequence that may lead to chemical alterations. The resulting chemical stabilization process, which occurs during, immediately following, and occasionally days after irradiation, often leads to physical and chemical cross-linking or chain scission. The physical changes to materials can include embrittlement, discoloration, odor generation, stiffening, softening, and enhancement or changes in chemical structure. This paper discusses how and why irradiated polymeric materials, including those of biological origin, may change their structure and effectiveness during and after exposure to gamma irradiation, and the potential impact of these changes on serum during irradiation…
BioProcessing Journal Posts
This article examines two interrelated animal welfare topics: the transportation of pregnant cattle, and the collection of fetal bovine serum (FBS). The occurrence of pregnant cattle at slaughter is unavoidable because of health, management, and economic reasons, or because farmers may be unaware of their pregnancy status. Since cattle are often sold to slaughterhouses through intermediaries, the pregnancy status of the cow is usually unknown until after it has been slaughtered and the uterus exposed. In slaughterhouses where fetal blood is collected, technicians are responsible for the detection and proper handling of fetuses, making sure they remain inside the uterus until dead, or are immediately euthanized. The harvesting of fetal blood also provides a possible source of information, which upon request, may help farmers improve the management of their livestock operations. The serum industry endorses the animal welfare standards set forth by the World Organization for Animal Health (OIE), as well as all existing local and national standards relating to the transportation of pregnant cattle and the collection of fetal blood. This article concludes that there is nothing negative or unethical about collecting blood from a dead fetus. Rather it would be unethical not to utilize available fetal tissues obtained from the slaughter of pregnant cattle, especially since FBS, used as an ingredient in cell culture media, contributes greatly to the advancement of the life sciences industry, as well as the replacement and reduction of live animals used in research and testing…
Biopharmaceutical manufacturing often takes place in tank farms – facilities in which large-volume vessels are used to support cell culture processes with equally sized, or even larger buffer preparation and storage tanks to support downstream processing. While the large cell culture vessels used to produce products are justifiable, current downstream buffer management approaches relying on high-capacity tanks lead to constraints on facility construction, operations, and plant flexibility….
Medicago manufactures influenza vaccine virus-like particles (VLPs) in an unusual production platform consisting of Nicotiana benthamiana plants. During the in vitro adventitious agent test (AAT) of certain Medicago B strain influenza vaccine VLP test samples, positive hemagglutination of guinea pig red blood cells was observed on day 14, but not on day 28. The positive result in the assay was surprising because the production process uses no animal-derived raw materials and contains a viral inactivation step. Plant-associated viruses would not be expected to infect the mammalian cell-based assay. No cytopathic effects or hemadsorption of red blood cells was observed in these AATs. The positive hemagglutination was observed at 2–8°C, but not at 36–38 °C, and only in a few of the six detector cell lines used in the assay. Because this is quite an unusual pattern of responses for an AAT, Medicago and the contract testing lab, Eurofins Lancaster Laboratories (ELLI) investigated the positive responses thoroughly for the presence of an adventitious agent or an alternative explanation not involving a viral contaminant. Investigation results indicated that the hemagglutinating activity associated with the vaccine test sample itself was responsible for the positive hemagglutination response. The positive hemagglutination on day 14 of these AATs was deemed an assay artifact, and preventive actions were taken to prevent recurrence of this type of false positive response…
The current draft of ICH Q12 appears to have taken several steps backward in the pursuit of the manufacturing excellence initiated by ICH Q8 (R2) pharmaceutical development and expanded by FDA’s 2011 process validation guidelines…
Bead matrices have been used in affinity chromatography to purify molecules in multiple applications. For instance, the hepatitis B surface antigen (HBsAg) is one of the molecules purified by this technique for human vaccine development programs. However, the use of monolithic supports have emerged as the advantageous choice for affinity chromatography based on convective mass transfer, a high number of channels, and low backpressures at high flow rates. For this reason, several experiments were conducted to determine the suitability of CB.Hep-1 monoclonal antibody (mAb) immunosorbent developed on carboxyimidazole (CDI)-monolithic supports (ligand concentrations: 0.5, 1.0, and 7.0 mg/mL) for HBsAg particle purification. Key results from this study show the highest amounts of HBsAg adsorbed (3059.31 ± 865.71 µg HBsAg/mL immunosorbent, n = 2), and HBsAg eluted (2884.50 ± 541.01 µg HBsAg/mL immunosorbent, n = 2), were estimated in the 1.0 mg/mL-CDI-CB. Hep-1 mAb monolithic support immunosorbents. In addition, the ligand leakage was always < 3 ng mAb/µg HBsAg (approved limit) in the 1.0 mg/ mL-CDI-CB.Hep-1 mAb immunosorbents. Experiments also evidenced the high purity and molecular homogeneity of purified HBsAg particles (< 95 %) across 20 purification cycles. Therefore, the ligand concentration could be reduced up to 1.0 mg/mL, which would enable a notable decrease in the mAb amount required for vaccine manufacturing, as compared to bead matrices (4.0 mg/mL). This study demonstrated that CDI-CB.Hep-1 mAb monolithic support immunosorbents are best suited for assessing the large-scale purification performance of HBsAg particles for human vaccine development programs at low ligand concentration and high flow rates...
Growth performance testing in cell culture is an effective approach to making serum suitability and purchase decisions. An independent commercial testing lab conducted two separate and sequential growth promotion studies to underscore the need for pre-purchase lot performance testing with: (1) FBS; and (2) FBS alternatives. Results from both studies are presented here to compare and contrast:
• FBS lots to each other
• FBS alternatives lots to each other
• FBS alternatives lots to FBS
FBS alternatives are included because they are often overlooked as a cost-effective substitute for FBS, providing, in many cases, equivalent performance. It is advisable to avoid preconceived notions concerning the quality or performance of a serum product without considering the culture system, culture conditions, and the subject cells, which can all have a material impact on its performance in cell culture.
Test – then decide…
Achieving very high levels of pharmaceutical product quality, particularly for the next generation of biologics, will require proactive use of a broad range of quality and process development tools throughout the therapeutic’s development and manufacturing lifecycle. These tools are most effective when integrated using an expanded form of FDA’s 2011 process validation guidelines. This article explains how process validation can be combined with quality by design (QbD), ICH Q8 design space (DS) and control strategies (CS), process analytical technology (PAT), and quality risk management (QRM) tools to provide a path to manufacturing very high-quality products. The approach establishes clear goals and then proactively builds appropriate control systems during process development to assure continuous control and verification of all manufacturing activities. Prospectively using the tools over the complete manufacturing lifecycle, from preclinical through commercial manufacturing, is particularly important to assure comparability from early product research and development all the way to commercialization. The continued evolution of these quality tools, as well as building new tools, will provide a path for the pharmaceutical industry to reach and maintain Six Sigma levels of product quality…
This paper reviews the importance of maintaining low temperature storage and handling (i.e., cold chain) for animal serum through all stages of processing, from finished product to the actual end-user. This cold chain extends from serum manufacture through the irradiation process, during shipment back to the supplier post-irradiation, as well as storage at supplier, irradiation, and end-user facilities. Anecdotal experience and theoretical considerations emphasize the point that maintenance of the cold chain is necessary for preserving the performance of serum for cell culture and other applications…