An astonishing range of viruses has provided building blocks for gene delivery systems, from the simple adeno-associated virus with a 5 kb genome to the complex poxviruses with 300 kb. This review focuses on non-replicating viral vectors that infect host cells just once, without producing infections virus. Viral vectors are generally characterized by several criteria, including their ability to integrate into the host genome, coding capacity, titer, toxicity, immunogenicity, host range, duration of gene expression, and transient or stable production systems. These are precisely the features that need to be carefully studied in the context of the application when deciding which vector to use…
BioProcessing Journal Posts
In the past, most large construction projects used a system called design-bid-build. Now, pharmaceutical companies planning cleanrooms have begun using an improved system, design-build, which can save millions of dollars and cut months from construction schedules. Design-build also can provide better quality end results than design-bid-build…
Long-term growth of the biopharmaceutical industry is increasingly relying on outsourcing to overcome the current capacity constraints, especially for monoclonal antibody production. Companies are often reluctant to commit to building multimillion dollar manufacturing facilities for potential products with no guarantee of approval. Therefore to offset risks, companies will enter into contract manufacturing arrangements…
Tissue engineering is an emerging area of biotechnology that will provide replacement tissues for patients, as well as complex, functional biological systems for research and testing in the pharmaceutical industry. A new research area of tissue engineering is the investigation of how living cells interact with and respond to synthetic biomaterial surfaces. The clinical developments that underlie that research include a number of novel tissue-engineered medical products (TEMPs)…
Monoclonal antibodies constitute a significant percentage of the protein-based therapeutic molecules currently in clinical trials. The broad applicability and proven commercial success for this class of molecules suggest a larger future market potential. The current biopharmaceutical manufacturing capacity is widely anticipated to be a rate-limiting factor in the growth of the biotech sector. Because antibody therapeutics represent such a large part of this market, and because the therapeutic dosages of antibodies tend to be greater than most biopharmaceuticals, there is an immediate need for novel antibody manufacturing approaches that deliver significantly greater productivity…
Over 25 years have elapsed since Kohler and Milstein electrified the immunology community with their article describing the reliable preparation of monoclonal antibodies (MAbs) by fusing immune splencytes with immortalized myeloma cells. This discovery not only garnered the pair of scientists a Nobel Prize, but also led to the development of a technology which has yielded a number of important therapeutic, prophylactic, and diagnostic products for in vivo human use, and hundreds of in vitro diagnostic products. Some of these products proved to be significant in meeting previously unmet medical needs, and a few have been commercial successes. But the path, from Kohler and Milstein’s discovery to commercial products, was discontinuous and a bit bumpy, and the technology continues to evolve…
Xenotransplantation has been defined by the US Public Health Service (PHS) as any procedure that involves the transplantation, implantation, or infusion into a human recipient of either (a) live cells, tissues, or organs from a nonhuman animal source, or (b) human body fluids, cells, tissues, or organs that have had ex vivo contact with live, nonhuman animal cells, tissues, or organs (PHS Guideline on Infectious Disease Issues in Xenotransplantation). In the US, several xenotransplantation clinical trials are in progress under US Food and Drug Administration (FDA) oversight. The PHS and the FDA have issued guidelines and guidance documents to address the potential for cross-species infection posed by the use of xenotransplantation products in humans. To minimize the infectious disease risk, these documents provide recommendations on how to screen and maintain source herds, individual source animals, and when possible, xenotransplantation products themselves. However, while precautions can be put in place to remove exogenous infectious agents, the endogenous retroviruses that a source species may carry cannot be removed…
Organizations developing biopharmaceuticals are often faced with the challenge of developing, as rapidly as possible, a production system for a recombinant protein or antibody intended for use in clinical trials. For expression of antibodies and other proteins with complex post-translational modifications, Chinese hamster ovary (CHO) cells are often the host of choice. However, isolation of CHO cell lines producing even moderate levels of a protein of interest is usually a lengthy process due to the need for at least one and usually several gene amplification steps. Gene amplification, which is usually accomplished through the dihydrofolate reductase (dhfr)/methotrexate system, is a requirement for most CHO expression vectors because the absolute expression level from each copy of an integrated expression plasmid is generally very low…
Large scale genomics spurred the development of massively parallel methods of automated DNA purification and sequencing. These methods started with the 1962 development of a 96-well microtiter plate for miniature-scale serology studies. This simple laboratory device has since been greatly modified and extended to include numerous specialty multiwell plates contructed and/or coated with different materials for various purposes. The original 96-well (8×12 matrix) has expanded to include 384-well and higher densities. More recently, functionality and versatility have been greatly augmented by the incorporation of a filter, or thin membrane, into the bottom of the well. These multiwell microfilter plates can thus be employed in a flow-through mode, in addition to the familiar “put in” and “take out” pipetting and rinsing steps associated with traditional enzyme-linked immunosorbent assay (ELISA) microtiter plate methods…
More than 130 drug and vaccine approvals for 95 entities over the last 20 years have generated roughly $30 billion in revenue for the biotech industry. The vast majority of this revenue comes from 30 proteins that have manufacturing bottlenecks resulting from the complexities of consistent protein production. The lag times involved in constructing mammalian cell fermentation facilities keeps supply of immensely successful high-volume drugs like Enbrel, Rituxan, and Remicade well below estimated demand. In other cases, the complexities of peptide synthesis threaten the potential of soon-to-be-launched or recently approved drugs like Fuzeon. The Pharmaceutical Research and Manufacturers of America (PhRMA) has documented more than 371 new biotech drugs in development, supporting the view that demand for many biopharmaceuticals will continue to outstrip supply. That number does not include the multitude of biotech drugs still in research stages…