Identification of Worst-Case Model Viruses for Low and High pH Inactivation
by Raymond Nims, S. Steve Zhou, and Mark Plavsic
Volume 16, Issue 1 (Spring 2017)
In this paper, we review the efficacy data for low and high pH inactivation of viruses in solutions (i.e., liquid inactivation) and discuss the mechanisms of action and the impact of temperature and treatment time, as these are the primary determinants of inactivation efficacy, besides pH, for different viruses. Only enveloped viruses were considered for low pH inactivation, as the literature concerning low pH inactivation of non-enveloped virus is not extensive and low pH is not considered to be an effective inactivation approach for most non-enveloped viruses. We conclude that for low pH treatment of enveloped viruses, and high pH treatment of both enveloped and non-enveloped viruses, an enteric flavivirus such as bovine viral diarrhea virus represents a worst-case model virus...
Citation:
Nims R, Zhou SS, Plavsic M. Identification of worst-case model viruses for low and high pH inactivation. BioProcess J, 2017; 16(1): 7–14. https://doi.org/10.12665/J161.Nims.
Posted online May 8, 2017.
Opinion
The Key to Meeting Future Challenges: Forcing Complexity into Simplicity by Making it Straightforward
by Mark F. Witcher, PhD
Volume 16, Issue 1 (Spring 2017)
Unless the trend of ever-rising product development costs is reversed, as demonstrated by Eroom’s law (look it up), the development of new biopharmaceutical products is doomed. In my opinion, the primary culprit is the industry’s inability to competently deal with complexity...
Citation:
Witcher MF. The key to meeting future challenges: forcing complexity into simplicity by making it straightforward. BioProcess J, 2017; 16(1): 5. https://doi.org/10.12665/J161.Witcher.T.
Posted online May 8, 2017.
Assessment of Affinity Chromatography Matrices in Plantibody Purification from Aqueous Two-Phase Extraction Samples
by Williams Ferro, Tatiana Alvarez, Déborah Geada, Yenisley Medina, José Montero, Andrés Tamayo, Ariadna López, Daily Hernández, Mayra Wood, Tatiana González, Regla Somoza, José García, Dobián Cecilia, Yanara González, Osmaro González, David Gavilán, Mailyn LaO, and Rodolfo Valdés
Volume 15, Issue 4 (Winter 2016/2017)
Plantibody purification is not as efficient as antibody purification from serum, ascites, or mammalian cell cultures. It is characterized by the application of inefficient plantibody solid-liquid extraction systems, low plantibody recovery, and short lifetimes of expensive chromatography matrices. To overcome it, several protocols of liquid-liquid aqueous two-phase extraction (ATPE) combined with affinity chromatography were previously studied to purify the CB.Hep-1 monoclonal antibody, which showed an unexpectedly high recovery. However, a study of ATPE combined with several affinity chromatography matrices to purify plantibodies has not been reported so far. Therefore, a combination of the best ATPE protocol with five specific affinity chromatography matrices to purify a plantibody for vaccine manufacturing is described in this study. Positive outcomes from plantibody recovery (%), specific activity (%), yield (mg purified IgG/L of leaf extract), and productivity (mg purified IgG/L of leaf extract/h) were achieved. Plantibody purity did not show statistical differences among all samples (> 97%, p < 0.05), and protein A leakage was thousands of times smaller than toxic protein A for non-human primates. In summary, the combination of ATPE (10% PEG 4000/15% K2PO4, pH 5.5) with two specific affinity resins were well-suited for large-scale plantibody purification from tobacco plant leaves...
Citation:
Ferro W, Alvarez T, Geada D, Medina Y, Montero J, Tamayo A et al. Assessment of affinity chromatography matrices in plantibody purification from aqueous two-phase extraction samples. BioProcess J, 2017; 15(4): 43–51. https://doi.org/10.12665/J154.Valdes.A.
Posted online February 15, 2017.
Purification of a Divalent Version of Antibody Fragments Specific for a Novel Epitope of the Human Vascular Endothelial Growth Factor with Low Aggregate Level and High Purity
by Hasel Aragón, Lincidio Pérez, Dayron Ojeda, Daily Hernández, Sigifredo Padilla, Marcos González, Jorge Gavilondo, Marta Ayala, Alexis Mussachio, Mónica Bequet, Humberto Lamdan, Regla Somoza, Mayda Candelario, Andrés Tamayo, Cristina García, Gisela Calas, Yanara González, Adelma Pérez, and Rodolfo Valdés
Volume 15, Issue 4 (Winter 2016/2017)
Cancer is one of the leading causes of death worldwide, and the second leading cause of death in Cuba. To address this serious health problem, some research has involved suppressing tumor growth by inhibiting the angiogenesis process using several molecules including antibodies. A divalent version of antibody fragments, the CIGB-598a, with a molecular weight between 100 and 110 kDa, has been expressed in CHO cells specific for a novel epitope of the human vascular endothelium growth factor (VEGF). This material has been generated at the Center for Genetic Engineering and Biotechnology to support cancer research efforts. As in other studies involving the purification of recombinant molecules, CIGB-598a exhibited a high degree of aggregation in the CHO cell culture supernatant. This required the design of a downstream process capable of removing high levels of aggregates to obtain a highly pure target molecule for use in preclinical studies and human applications further down the road. We have developed a suitable downstream method based on the combination of three chromatography processes: affinity, cation-exchange, and anion-exchange that recover a relatively low level of CIGB-598a, but at a level of high purity (greater than 95 %) with fewer aggregates (below 1%)...
Citation:
Aragón H, Pérez L, Ojeda D, Hernández D, Padilla S, González M et al. Purification of a divalent version of antibody fragments specific for a novel epitope of the human vascular endothelial growth factor with low aggregate level and high purity. BioProcess J, 2017; 15(4): 32–41. https://doi.org/10.12665/J154.Valdes.P.
Posted online February 15, 2017.
Quality Risk Management (QRM): Part II – Evaluating the Impact of Process Parameters on Critical Quality Attributes for Biopharmaceutical Products
by Mark F. Witcher
Volume 15, Issue 4 (Winter 2016/2017)
This paper, the second in a three-part series on ICH Q9 quality risk management (QRM), uses a process-based risk structure to identify product quality risks from variability in input parameters and process behavior. This paper outlines a method to identify the three types of input parameters and how they can be placed into an ICH Q8 defined design space structured to clearly categorize and control the input parameters such that they can be evaluated for their impact on product critical quality attributes (CQAs). Based on their placement in the well-structured design space, the parameters are rated using a risk severity and uncertainty index to calculate a risk rating for review and acceptance. The process-based risk structure can also be used to mitigate the likelihood of the risk consequence by modifying the processes to manage the uncertainty of the input parameters and control the process’s behavior...
Citation:
Witcher MF. Quality risk management (QRM): part II – evaluating the impact of process parameters on critical quality attributes for biopharmaceutical products. BioProcess J, 2017; 15(4): 22–31. https://doi.org/10.12665/J154.Witcher.Q.
Posted online February 15, 2017.
Hydroxyethyl Starch Supplemented with Ice Recrystallization Inhibitors Greatly Improves Cryopreservation of Human Red Blood Cells
by Jessica S. Poisson, Jennie G. Briard, Tracey R. Turner, Jason P. Acker, and Robert N. Ben
Volume 15, Issue 4 (Winter 2016/2017)
Cryopreservation is a desirable method for the long-term storage of human red blood cells (RBCs). Current protocols employ high concentrations of glycerol that must be removed from thawed RBCs prior to transfusion. Small-molecule ice recrystallization inhibitors (IRI) can protect RBCs from cryoinjury during the freezing and thawing process in the presence of reduced amounts of glycerol. Although reducing the concentration of glycerol during freezing reduces post-thaw deglycerolization times, thawed RBC units still require post-thaw processing. Herein, we report the cryopreservation of RBCs using the non-permeating cryoprotective agent (CPA) hydroxyethyl starch (HES) supplemented with small-molecule IRIs: (1) PMP-Glc (110 mM); and (2) pBrPh-Glc (30 mM). The results demonstrate that 30 mM pBrPh-Glc in 11.5 % (w/w) HES affords quantitative post-thaw recovery of intact RBCs that are superior to those obtained using glycerol with slow cooling rates, and show the utility of small-molecule IRIs in cryopreservation...
Citation:
Poisson JS, Briard JG, Turner TR, Acker JP, Ben RN. Hydroxyethyl starch Supplemented with ice recrystallization inhibitors greatly improves cryopreservation of human red blood cells. BioProcess J, 2017; 15(4): 16–21. https://doi.org/10.12665/J154.Ben.
Posted online February 15, 2017.
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