A number of biopharmaceuticals are enzymes that act in vivo on high-molecular substrates. It can be a challenge to develop in vitro methods for accurately assessing their biological activity. Interest is also developing in using enzyme kinetic parameters as product quality attributes under the quality-by-design (QbD) initiative. Among biotechnology therapeutics, the conventional method of expressing potency is in units/mg of biopolymer. For enzymes, a unit of activity was defined in 1958 by the International Union of Biochemistry and Molecular Biology…
Upstream Processing
A Risk-Based Aproach to Establishing Animal-Component–Free Facilities
Bovine spongiform encephalopathy (BSE) and its potential to affect humans emerged as a concern in the 1990s. So suppliers of many essential animal-sourced components used in cell culture and fermentation processes became concerned about the potential for material contamination with prions. Viruses also can be present in raw materials derived from animal origins. Many important drug and vaccine products are made by mammalian cell culture or bacterial fermentation, so their biological safety is paramount. However, it is very difficult to…
Nutrient Supplementation Strategies for Biopharmaceutical Production, Part 2
Some of the numerous feeding strategies are more appropriate than others for certain types of cell culture production systems. Once a nutrient supplement has been identified as described in Part 1 of this three-part review (1), a supplementation strategy must be chosen. Supplementing at too great a rate may expose log-phase cells to stresses such as increased osmolality and lactate levels that would inhibit biomass expansion. But inadequate supplementation can lead to early apoptosis through rapid depletion of selected important…
Nutrient Supplementation Strategies for Biopharmaceutical Production
Cell-culture–related in vitro recombinant protein production is currently a $70-billion/year business. In 2007, biotech drug sales grew by 12.5%, twice as fast as standard pharmaceuticals (1). Current ongoing efforts to maximize productivity in both time and volume directly affect the scale and capital investment required for a bioreactor suite. As cells reach higher concentrations more quickly while each cell pumps out more product than ever before, the number and scale of bioreactors can be reduced. To that end, not only…
Rethinking Media Performance
Fetal bovine serum (FBS) was — and in many cases still is — the supplement of choice to maintain the viability of mammalian cells in culture. However, there are considerable limitations to its use. In the early days of cell culture, the issues surrounding serum were mainly its variable performance and the potential to contaminate cultures with fungi, viruses, and bacteria. Early attempts to produce a serum-free medium (SFM) were academic exercises that usually relied on the use…
Using Innovation to Drive Competitive Advantage
Figure 1: () STOCKXPERT (WWW.STOCKXPERT.COM) After spending decades as the “sleepy†segment of the biopharmaceutical industry, vaccines are now seen as one of its highest growth segments. Major pharmaceutical companies — Novartis AG (www.novartis.com) and Pfizer, Inc. (www.pfizer.com), for example — are aggressively entering this area. Those already in it are expanding capacity and increasing business development activity. Indeed, access to the vaccines business was a major driver of Pfizer’s acquisition of Wyeth Pharmaceuticals (www.wyeth.com) (1). Several factors…
Maintaining Product Titer While Replacing Undefined Components in a CHO Culture System
Proteins, hydrolysates, and lysates of plant or yeast origin are commonly used in cell culture media for large-scale manufacturing processes for human biotherapeutics. Lot-to-lot variability in the composition of such constituents is well established and can affect multiple biological performance indicators. Our goal was to replace an undefined, protein-containing medium with a chemically defined medium (meaning the chemical structure and concentration for each component in a formulation is known). Such a formulation should be free of protein and…
Development and Qualification of a Generic IgG Quantification Assay Using Surface Plasmon Resonance
Fast, precise, and accurate quantification technologies are indispensable for efficient process development in applications such as IgG production in a GXP environment. Based on surface plasmon resonance (SPR) technology, the Biacore C system from GE Healthcare (www.biacore.com) is an alternative technology for IgG quantification that has benefits over traditional methods. Assay development is simplified and accelerated due to real-time detection. Assay hands-on time is reduced, and sample throughput can be increased using automation and efficient data evaluation with regulatory-compliant software.…
Automated Liquid Handlers As Sources of Error
Use of automated liquid handling equipment for rapid testing and reproducible screening of thousands of molecules, cells, and compounds has become an essential component of life-science laboratories across the globe. Along with an increase in such use, transferred volumes have shrunk, as demands increase on transfer accuracy and precision when aspirating, diluting, dispensing, mixing, and washing. Automated liquid handlers are generally used to increase the productivity and repeatability of volume transfer, but as discussed here, they are still prone to…
A Single-Use, Scalable Perfusion Bioreactor System
We have previously described a patented nonsparging, nonbubbling oxygen transfer method (1). This method is based on interaction between the air-exposed smooth surface of a bioreactor vessel and culture medium repeatedly sweeping across it with a certain force, which seems to generate microscopic bubbles among the water molecules (2). We manufactured high–oxygen-transfer Current suspension bioreactors with working volumes of 5 L, 50 L, 150 L, and 300 L. Here we describe the use of these suspension bioreactors as “artificial lungs”…