Gamma Irradiation of Animal Serum: General Regulatory Environment and Process Controls
by Greg Hanson, Bart Croonenborghs, Mara Senescu, Huw Hughes, Raymond Nims, and Rosemary Versteegen
Volume 18, Open Access (February 2019)
This is the sixth and last in a series of articles describing and demystifying the processes involved in the gamma irradiation of serum. This serum treatment is intended to mitigate the risk of introducing adventitious contaminants into cell cultures. In this article, we discuss the regulatory environment under which gamma irradiation of serum is performed, and provide additional details on best practices for documentation of the irradiation process, selection of the contract irradiator, evaluation of risk versus benefit needed to arrive at the radiation dose range to be used, as well as an understanding of the level of remaining risk following irradiation at that dose range. Gamma irradiation should not be viewed as a means of totally eliminating risk, but rather as a means of reducing the risk of introducing adventitious agents into cell cultures. A balance must be achieved between the desire to eliminate all adventitious contaminants, and the need to retain the desired performance characteristics of the serum, once irradiated...
Citation:
Hanson G, Croonenborghs B, Senescu M, Hughes H, Nims R, Versteegen R. Gamma irradiation of animal serum: general regulatory environment and process controls. BioProcess J, 2019; 18. https://doi.org/10.12665/J18OA.Hanson
Posted online February 11, 2019.
Evaluation of a Single-Use Benchtop Process Development System to Optimize Cell Growth and Scale-Up of Veterinary Vaccine Production
by Lídia Garcia, Mercedes Mouriño, Alicia Urniza, and Sandra Juanola
Volume 18, Open Access (February 2019)
In the past 20 years, mammalian cell lines have been utilized to produce many viral veterinary vaccines. Cell lines such as baby hamster kidney (BHK)-21, Vero, and Madin Darby canine kidney (MDCK) are widely used because they help facilitate shorter manufacturing lead times and tighter process controls. As compared to other biotech products, viral vaccine manufacturing processes present some specific constraints linked to the cell substrates used. With the global veterinary vaccine market value predicted to be almost $7 billion per year by 2021[2], to remain competitively priced as well as profitable, bioprocess scientists are under pressure to develop methods for faster and more cost-efficient cell culture production. This has led to a shift from the use of expensive, two-dimensional T-flask and roller bottles to single-use, stirred tank bioreactors with microcarriers, or the adaptation of attachment-dependent cell lines such as BHK-21 for suspension culture. This requires time-consuming optimization and scale-up development experiments, which are real drawbacks. However, utilizing automated, single-use mini bioreactors as a scale-down model can enable more efficient use of time and optimization of media, feed, and culture conditions to de-risk upstream process development. In this article, single-use, mini bioreactors are evaluated to determine if they are geometrically comparable to benchtop bioreactors (both glass and single-use vessels) and pilot-scale, single-use bioreactors for effectively modelling mammalian cell culture at 2 L and 50 L scale...
Citation:
Garcia L, Mouriño M, Urniza A, Juanola S. Evaluation of a single-use benchtop process development system to optimize cell growth and scale-up of veterinary vaccine production. BioProcess J, 2019; 18. https://doi.org/10.12665/J18OA.Garcia
Posted online February 11, 2019.
Gamma Irradiation of Animal Serum: Theoretical Basis of Impacts of Gamma Irradiation on Biological and Synthetic Polymers
by Karl Hemmerich, Randy Fitzgerald, Dennis Hallett, Raymond Nims, and Rosemary Versteegen
Volume 18, Open Access (January 2019)
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...
Citation:
Hemmerich K, Fitzgerald R, Hallett D, Nims R, Versteegen R. Gamma irradiation of animal serum: theoretical basis of impacts of gamma irradiation on biological and synthetic polymers. BioProcess J, 2019; 18. https://doi.org/10.12665/J18OA.Hemmerich
Posted online January 28, 2019.
Fetal Bovine Serum and the Slaughter of Pregnant Cows: Animal Welfare and Ethics
by Ole Bødtker Nielsen and Percy W. Hawkes
Volume 18, Open Access (January 2019)
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...
Citation:
Nielsen OB, Hawkes PW. Fetal bovine serum and the slaughter of pregnant cows: animal welfare and ethics. BioProcess J, 2019; 18. https://doi.org/10.12665/J18OA.Hawkes.
Posted online January 10, 2019.
Deploying Automated Buffer Production for cGMP Use: Points to Consider
by Amos M. Tsai, Enrique Carredano, and Karolina Busson
Volume 18, Open Access (January 2019)
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....
Citation:
Tsai AM, Carredano E, Busson K. Deploying automated buffer production for cGMP use: Points to consider. BioProcess J, 2019; 18. https://doi.org/10.12665/J18OA-Tsai.
Posted online January 8, 2019.
Investigation of an Adventitious Agent Test False Positive Signal in a Plant-Derived Influenza Vaccine
by Todd L. Talarico, Michael Murphy, Raymond Nims, Dan Hastings, Jeri Ann Boose, and Dave Dumers
Volume 17, Open Access (October 2018)
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...
Citation:
Talarico TL, Murphy M, Nims R, Hastings D, Boose JA, Dumers D. Investigation of an adventitious agent test false positive signal in a plant-derived influenza vaccine. BioProcess J, 2018; 17. https://doi.org/10.12665/J17OA.Talarico.
Posted online October 31, 2018.
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