Profiling Intracellular Monoclonal Antibody Expression for Improved Cell Culture Characterization and Process Optimization

by Matthew S. Manahan and Wai Lam W. Ling, PhD
Volume 8, Issue 3 (Fall 2009)

Many laboratories have utilized cell-free systems or prokaryotic systems designed to produce biological molecules with single polypeptide chains, limited folding requirements, and without glycosylation. The yeast systems are used to generate glycoproteins; however, their glycosylation profiles are vastly different from those of mammalian cells. Without significant glycoengineering, the yeast-produced recombinant glycoproteins may be unsuitable as therapeutic molecules. As such, the use of mammalian cells is still the preferred method to produce complex biological molecules...

Citation:
Manahan MS, Ling WLW. Profiling Intracellular Monoclonal Antibody Expression for Improved Cell Culture Characterization and Process Optimization. BioProcessing J 2009; 8(3): 32-37.

Peptide Synthesis in Pharmaceutical Manufacturing

by Gary Hu
Volume 8, Issue 3 (Fall 2009)

Amino acids are the most basic of building blocks in physiology, which is why peptides (oligomers iof amino acids) are continuing to grow in prominence among pharmaceutical manufacturers. With inherent abilities to block and/or enhance signal transfers in the human body, peptides, when harnessed as active pharmaceutical ingredients, can treat a host of metabolic diseases, cardiovascular and heart conditions, and neurodegenerative disorders. Peptide-based drug targets are being identified at an increasingly rapid pace, both in terms of recently introduced therapies, and products in the development pipeline...

Citation:
Hu G. Peptide Synthesis in Pharmaceutical Manufacturing. BioProcessing J 2009; 8(3): 51-53.

Optimization of Baculovirus-Mediated Gene Delivery into Vertebrate Cells

by Kari Airenne, PhD
Volume 8, Issue 3 (Fall 2009)

Baculoviruses are large rod-shaped DNA-viruses which specifically infect only arthropods, mostly lepidopteran species. Among the over 600 known species, Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is the most characterized and widely used. The baculovirus genome is poorly transcribed and does not replicate in non-target cells. Thus, baculoviruses are harmless for vertebrates even though they can be found everywhere and we eat them daily on our vegetables. Baculoviruses have been applied in biotechnology for almost a century now, first as biopesticides (since the 1920s), then for recombinant protein production (since the early 1980s), and most recently for gene delivery into vertebrate cells (since the mid-1990s)...

Citation:
Airenne K. Optimization of Baculovirus-Mediated Gene Delivery into Vertebrate Cells. BioProcessing J 2009; 8(3): 54-59.

Functionally-Improved Recombinant Antibodies: Moving Toward Higher Levels of Expression

by Christian Kranz, PhD, Michael Liss, PhD, Frank Notka, PhD, Michael Spring, PhD, and Ralf Wagner, PhD
Volume 8, Issue 3 (Fall 2009)

Directed evolution has profoundly changed the way antibodies or antigen binding fragments (Fab) are produced today. Lead generation for product candidates is oftentimes based on complex combinatorial libraries containing a large collection of variant antibodies. The selection of candidate molecules by screening procedures like phage display is considered the gold standard. One major advantage of these methods is that initial candidate molecules can be further improved in terms of affinity, specificity, etc. by reiterative in vitro maturation processes using the very methods that have been used for lead generation...

Citation:
Kranz C, Liss M, Notka F, Spring M, Wagner R. Functionally-Improved Recombinant Antibodies: Moving Toward Higher Levels of Expression. BioProcessing J 2009; 8(3): 44-50.

Characterization and Qualification of Cell Substrates for Manufacturing Viral Vaccines in the United States

by Arifa S. Khan, PhD
Volume 8, Issue 3 (Fall 2009)

Cell substrates are used in various stages of viral vaccine manufacturing, as in the isolation, selection, and propagation of the virus seed or virus vector stock, as well as for the amplification of the virus to produce the final vaccine product. The various stages of cell substrate use, including cell banking, are shown in a generic manufacturing scheme in Figure 1. Traditionally, viral vaccines have been produced in animal tissues, primary cell cultures, and cell lines that either have a finite life span, such as normal diploid cells, or a theoretically infinite life span, as achieved with continuous or immortalized neoplastic cells. The cell substrates used in viral vaccines currently licensed in the US are listed in Table 1...

Citation:
Khan AS. Characterization and Qualification of Cell Substrates for Manufacturing Viral Vaccines in the United States. BioProcessing J 2009; 8(3): 8-12.

Applying Modern Design of Experiments to Mass Transfer Characterization in Bioreactors

by Priyal Sheth and Semsi Ensari, PhD
Volume 8, Issue 3 (Fall 2009)

Mass transfer is one of the most crucial parameters during scale-up in cell culture, and may cause variations in specific yields. At the cellular level, all the cells require proper supplementation of essential nutrient sources: nitrogen, oxygen, and carbon. The ability of cells to grow, maintain viability, and provide high specific productivity depends on the proper distribution of these nutrients. The latter depends on proper mass transfer to supply oxygen, carbon, and nitrogen through agitation and aeration, along with other micronutrients...

Citation:
Sheth P, Ensari S. Applying Modern Design of Experiments to Mass Transfer Characterization in Bioreactors. BioProcessing J 2009; 8(3): 38-43.

A Summary of the Manufacture, Biochemical Characterization, and Virological Safety Demonstration of the Mouse mAb CB.Hep-1 Used to Produce the Hepatitis B Vaccine

by Rodolfo Valdés, PhD et al.
Volume 8, Issue 3 (Fall 2009)

Monoclonal antibodies (mAb) are highly selective molecules, and an unlimited amount of mAbs with equal quality can be produced using mammalian cell cultures and animals. These molecules have remarkable applications in biomedicine, diagnosis and therapy due to the ability to reproduce exactly the same binding properties. The mAbs have been generated against an ostensible set of compounds such as toxins, drugs, blood proteins, cancer cells, viruses, hormones, environmental pollutants, food products, metals and plant materials. In general, mAbs can also be used for creating sensitive tests to detect small amounts of substances, and in therapies, abzymes, and for isolating specific compounds from complex mixtures by immunoaffinity chromatography (IAC)...

Citation:
Valdés R et al. A Summary of the Manufacture, Biochemical Characterization, and Virological Safety Demonstration of the Mouse mAb CB.Hep-1 Used to Produce the Hepatitis B Vaccine. BioProcessing J 2009; 8(3): 13-31.

Tracking Pipetting Performance in the Primeval Wilderness of the Pacific Northwest (part 4)

by A. Bjoern Carle, PhD and Doreen Rumery
Volume 8, Issue 1 (Spring 2009)

Fresh on the heels of Mission #3 at the stiflingly hot Death Valley National Park, the ARTEL Extreme Pipetting Expedition team looked forward to visiting the temperate and humid Olympic National Park. Known for its lush, rainforest-like conditions, Olympic is home to 266 glaciers, more than 60 miles of rugged Pacific coastline, and over 140 inches of rainfall each year. It also has the Northwest’s largest remaining acreage of undisturbed rain forests...

Citation:
Bjoern Carle A, Rumery D. Tracking Pipetting Performance in the Primeval Wilderness of the Pacific Northwest. BioProcessing J 2009; 8(1): 56-59.

Testing Strategies for Mammalian Cell Banks

by Michelle Quertinmont, James Moldenhauer, and Dayue Chen
Volume 8, Issue 1 (Spring 2009)

Contamination by adventitious agents (bacteria, fungi, mycoplasma, and viruses) represents potential safety risks for biologics produced in mammalian cells. Bacterial and fungal contaminations are usually easy to detect in culture medium due to changes in pH and visual indicators such as color and opacity. Mycoplasma contamination has been detected in 15–35% of cell lines deposited in some cell culture collection. This is because mycoplasma contaminations often cause little changes that can be readily detected by visual inspection.  However, bacterial, fungal, and mycoplasma contamination can be more effectively controlled than viral contamination by careful screening of initial parental cell banks, proper environmental monitoring, along with ongoing testing…

Citation:
Quertinmont M, Moldenhauer J, Chen D. Testing Strategies for Mammalian Cell Banks. BioProcessing J 2009; 8(1): 18-22.

Tangential Flow Filtration Membranes For the Washing of Escherichia Coli Cells

by Geraldine Eschbach and Steve Vermant
Volume 8, Issue 1 (Spring 2009)

Microbial fermentation is used to produce such products as therapeutic proteins, antibiotics, hormones, enzymes, amino acids, blood ­substitutes and ­alcohol. These products may be expressed by the microbial cells themselves, expressed intracellularly in the cytoplasm or, in the case of bacterial cells, in the periplasmic material. Before any intracellularly-produced molecules can be used and further purified, the cells (i.e., E. coli) must be concentrated and set in an ­appropriate buffer (cell washing) before being lysed. Then after lysis, molecules of ­interest have to be separated from the ­parent cells and then clarified to remove ­cellular debris and other contaminants. Depending on the process used, additional clarification steps may be necessary…

Citation:
Eschbach G, Vermant S. Tangential Flow Filtration Membranes For the Washing of Escherichia Coli Cells. BioProcessing J 2009; 8(1): 46-48.