BioProcessing Journal Posts

One of the biggest challenges in the production of recombinant therapeutic proteins, monoclonal antibodies, and vaccines is the clarification and separation of the product (typically a protein) from the cell culture or fermentation broth. The desired product is present in low concentrations and must be efficiently separated from the other components present in the bioreactor fluid. An overall objective in developing a clarification process is to achieve the highest level of product recovery (yield) and contaminant removal with the fewest number of unit processes. Understanding how each operational step affects the performance of the next step downstream is the challenge at hand. Centrifugation, in combination with depth filtration, is gaining acceptance as the preferred method for the removal of cells, cell debris, colloids, insoluble precipitants, aggregates, and other materials found in mammalian cell culture and bacterial fermentation fluids…

Biologics Production

Within the biopharmaceutical industry, mammalian cell culture is extensively used to manufacture a various biopharmaceutics uncluding antibodies, interferons, hormones, crythropoietin, clotting factors, immunoadhesins, and vaccines. The market for monoclonal antibodies (MAbs) alone is expected to grow 30% a year and reach sales of nearly $6.5 billion in 2004. The vast majority of these biotherapeutics are secreted glycoproteins obtained from mammalian cell lines such as: Chinese hamster ovary (CHO), human embryonic kidney 293 (HEK-293 or 293). NS0, and baby hamster kidney (BHK). As is the goal with most commercial products, biotechnologists strive to generate these valuable proteins in the highest yields possible in order to utilize mammalian bioreactor facilities efficiently…

Biologics Production

Process development is an investment. As with a personal retirement plan, the importance of making the investment is not in question, yet strategies for when, how much, and where to invest in process development vary significantly from company to company. For a personal retirement plan, the answers to these questions are straightforward: invest as early as you can and as much as you can, and take less risk the closer you get to retirement. This would also be sound advice for investing in process development (substituting “BLA filing” for “retirement”) were it not for two complicating factors. First, the majority of biotherapeutics that enter the clinic fail to make it to the market. This makes a large, early investment in process development less attractive. Second, there is extreme pressure to get into the clinic, and subsequently onto the market, as quickly as possible, minimizing the time available for process development…

Biologics Production Manufacturing

The biopharmaceutical manufacturing sector is rapidly gearing up production capacity to satisfy the steadily escalating global demand for complex biologics to combat a number of treatable illnesses. Frequently, the biotherapeutics in demand are too complicated to be chemically synthesized and thus are beyond the reach of traditional pharmaceutical approaches. To effectively address this issue, these products must be developed and produced using viable and robust biological systems…

Biologics Production Manufacturing

The use of plants as protein expression hosts for human therapeutic proteins is emerging as a safe and cost-effective alternative to microbial and mammalian cell culture. Pharmaceutical protein production is typically carried out in microbes and mammalian cell culture because of their high production potential and/or ability to produce complex eukaryotic proteins. However, immense costs are typically required for production facilities to support their growth. To offset these costs, companies usually build and expand a production facility over several years. In fact, it has been predicted that the demand for high-value pharmaceuticals produced by cell culture will quickly surpass the ability of pharmaceutical companies to produce them…

Biologics Production

The first use of mammalian cell culture for the production of vaccines dates back to polio vaccine development in the 1950s. The development of hybridoma technology in the 1970s further stimulated the use of mammalian cells for the production of monoclonal antibodies. Together with developments in genetic engineering, it therefore became possible to produce a wide range of recombinant proteins as well as to improve cell metabolism. Animal cells are now widely used in industrial processes to obtain complex glycoproteins with correct posttranslational modifications and biological activity for diagnostic and therapeutic applications. Animal cells are the main source for commercially available recombinant proteins such as tissue plasminogen activator (tPa), erythropoietin (EPO), DNAse, factor VIII, interferon-ß, and monoclonal antibodies…

Biologics Production

The modern age of blood transfusion began after the Second World War, as detailed in Douglas Starr’s book, Blood: An Epic History of Medicine and Commerce. During the war, it became apparent that early and aggressive medical treatment utilizing whole blood or plasma could increase the chances of survival for military personnel wounded in combat. In the United States, a national program to encourage blood donation was created to provide the needed blood, which was then shipped as whole blood or plasma to war zones. After the war, physicians were eager to apply surgical advances developed on and off the battlefield to the care of the general population. Because these advances relied on blood transfusion, for the public to realize their benefit, adequate supplies of whole blood and blood components needed to be available to hospitals across the country. This was often not the case…

Cell & Tissue Banking Manufacturing

More than 70 percent of all prospective gene transfer/gene therapy protocols are designed to treat metastatic cancer. A large number of such protocols involve strategies to attempt cancer immunization via cell-based gene transfer of cytokines or tumor antigens, while others involve the delivery of oncolytic viruses or vectors bearing prodrugs, chemoprotective agents, antisense constructs, or tumor suppressor genes. However, a major unresolved problem that has impeded the progress of cancer gene therapy to the clinic is that of inefficient gene delivery to target cells in vivo. In this regard, the advent of pathotropic targeting launches a new paradigm in cancer gene therapy. By targeting the histopathology of the cancerous lesion — rather than the cancer cells per se — to effectively concentrate the gene vector within primary and metastatic tumors, the safety and efficacy of intravenously administered vector nanoparticles were increased significantly in animal models of cancer. This article describes the development of the pathotropic Targeted Delivery System (TDS) that now serves as the guidance system for “smart” nanoparticles bearing designer killer genes for cancer gene therapy…

Cell & Gene Therapy

Variation of viral titre and recombinant product yields reported for the baculovirus expression vector system have been attributed to many specific infection variables. These include multiplicity of infection (MOI) and cell density at time of infection and time of harvest, as well as virus bank quality and efficiency. The MOI is defined as the number of plaque forming units (pfu) per cell that are added at the time of infection. Virus titre (pfu/ml) is determined by the plaque assay method. The MOI parameter is easily manipulated and may be important in optimising recombinant protein yields. Other sources of variation during both cell growth and viral infection phases may be responsible for the range of reported yields. Past studies in our laboratory compared the behaviour of cells infected with high and low MOI values, specifically regarding nutrient limitation and deprivation. In addition to these aspects, the quality of the virus bank may be an important factor which influences heterologous protein yields in the insect cell baculovirus system. Thus, production yields may be correlated to virus efficiency…

Baculovirus Expression Technology Biologics Production

Parvoviruses are one of the most prevalent infectious agents in the laboratory rodent. Their effect on research can range from immune dysfunction that may mislead researchers when interpreting results to lethal effects on animals. Until recently parvovirus infection in mice was thought to be caused by minute mouse virus (MMV) and in rats by rat viral agents in the KRV or H-1 serogroups. Relatively newly discovered viruses in these groups are mouse (MPV) and rat parvoviruses (RPV-1 and 2). Parvoviruses are 15–20 nm in diameter and are single-stranded DNA viruses of about 5,000 nucleotides, which replicate through a double-stranded DNA intermediate. The protein composition consists of three structural or capsid proteins providing the viral coat (VP-1, VP-2, and VP-3) and two non-structural proteins involved in viral replication (NS-1 and NS-2). Among the capsid proteins,VP-2 is the major protein…

Biologics Production Research