Live whole-cell bacterial products have been used as vaccines for many years, and there are currently three such products licensed on the market. Over recent years, however, interest has renewed in this type of product as a delivery system for novel recombinant therapies and vaccines. A number of different organisms have been proposed, such as Escherichia coli and Salmonella species, which might have applicability for such applications. Vaccine applications tend to relate to the potential for low-cost orally delivered products…
Upstream Processing
Assay Validation for Rapid Detection of Mycoplasma Contamination
Mycoplasmas and related bacteria in the class Mollicutes are parasitic organisms found not only on the external surfaces of a wide range of eukaryotic host cells, but also intracellularly. They are characterized by small size and lack of a rigid cell wall, which gives them resistance to β-lactam antibiotics and the ability to pass through 0.2-µm filters (1,2). Contamination by Mollicutes is a common problem for cell cultures that is not easily detected because it usually does not produce turbidity…
Scaling Up a CHO-Produced Hormone–Protein Fusion Product
Many biotechnology companies recognize the powerful benefits of increasing product titer early in product development as a strategy to minimize manufacturing costs, scale, and the duration necessary to produce clinical supplies and achieve product commercialization. Additional benefits include minimizing or completely avoiding significant regulatory delays to market that can be caused by major process technology changes (such as cell line and product quality changes). Recently, another significant benefit has been realized too: Smaller, more productive and efficient 2,000-L…
Bridging the Gap from Reusable to Single-Use Manufacturing with Stirred, Single-Use Bioreactors
During the past few years, use of disposable bioreactors in development and manufacturing processes has become widely accepted. Particularly, low–oxygen-demanding cell types such as human and insect cells have proven to be perfectly suitable for cultivation in single-use bag chambers. These bioreactors have significant advantages over their reusable counterparts (1). They transform a single-purpose process using stainless steel reactors into a multipurpose facility in which switching from one application to another is both easy and cost effective. Reusable…
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…
Medium and Process Optimization for High Yield, High Density Suspension Cultures: From Low Throughput Spinner Flasks to High Throughput Millilitre Reactors
The most important contributions to high-yield manufacturing processes for the production of recombinant proteins from cultivated mammalian cells have come from the identification of highly enriched and well-balanced media formulations, and fine tuning the process conditions that support high cell culture densities with high specific productivity. The industry standard yield for immunoglobulins or similar molecules derived from suspension-cultivated mammalian cells in bioreactors has risen during the past 20 years from the tens of mg/L to g/L. The more…
Disposable Bioreactors in Cell Culture-Based Upstream Processing
During the last 10 years, cost pressures and the changing requirements for bioreactors in the modern pharmaceutical industry have resulted in the increased use of disposable bioreactors in both R&D and manufacturing. Numerous studies have demonstrated their efficiency in cell culture-based upstream processing at small- and middle-volume scales. As shown in Figure 1, disposable bioreactors with culture volumes between 10 mL and 2 m3 are most widely used for cell proliferation, screening experiments, the production of therapeutic agents…
Disposable pH Sensors
This paper describes the design, development and validation procedure for a novel, single-use gamma-stable electrochemical pH probe jointly developed by Sartorius Stedim Biotech SA and Metroglas. This new, single-use pH sensor offers a range of pH measurements (from 0 to 11 with ±0.1 precision) and features a one-point calibration process in its storage solution that provides a fast and easy pre- and post-use sensor performance check. Also described is a specific encapsulation device designed to integrate the pH…
A Readily Available Source of BSA Consistently Supports Cultivation and Differential Gene Expression
Lyme disease caused by the spirochete Borrelia burgdorferi is the leading vector-borne illness in the United States (1). The natural infectious lifecycle of B. burgdorferi is complex in that it is necessary for the bacteria to colonize both an arthropod vector (the Ixodes scapularis tick, pictured right) and a mammalian host (2). As the bacteria transitions between those two diverse niches, it alters the expression of its major outer surface proteins (Osps) such that expression of those that…
Many Considerations in Selecting Bioproduction Culture Media
Not long ago, the ability to support efficient large-scale culture of cells was the main factor in choice and development of production media. However, a number of new performance demands have been imposed on production media (as listed in the “Key Factors†box). These new criteria arise from such sources as the demand for increased efficiency in a number of production operations, goals invoked by new quality initiatives, and a more science-based approach to process development. Not only…