Bioprocess Technology: An Overview

• Overview of the emergence and impact of biotechnology and biopharmaceutical products
• Appreciation of the advantages of recombinant DNA (rDNA) technology

Bioprocess Technology

• A bioprocess uses living cells (e.g., bacteria, yeast, insect cells, mammalian cells) or their components (e.g., enzymes) to obtain desired products
• Bioprocess technology combines living matter (organisms or enzymes) with nutrients under specific optimal conditions to make a desired product
• Bioprocesses are classified into preparation, production, and purification
• In some Industries, bioprocesses in both production and purification are taken together as downstream processing
• Industrial settings need tight control over each bioprocess, from retrieving inoculum from a working cell bank to obtaining the final purified biopharmaceutical product
• Upstream processing involves understanding cell biology and nutrient requirements
• Downstream processing involves separation and purification

Historical Discoveries

• 1665: Robert Hooke described the cell
• 1675: Anton van Leeuwenhoek observed microorganisms through microscope
• 1839: Matthias Schleiden and Theodore Schwann proposed the Cell Theory
• 1859: Charles Darwin's theory of natural selection was released
• 1864: Louis Pasteur developed the pasteurization process
• 1866: Gregor Mendel defined the principle of heredity
• 1869: Johann Miescher performed the first chemical synthesis of nucleic acid
• 1910: Thomas Hunt Morgan discovered the location of genes on chromosomes
• 1928: Fred Griffith discovered the "transforming principle"
• 1941: George Beadle and Edward Tatum stated that one gene makes one enzyme
• 1944: Oswald Avery revealed Griffith's “Transforming” material is actually DNA
• Joshua Lederberg discovered bacteria conjugation and coined the term “plasmid” in 1952
• 1953: James Watson and Francis Crick deduced the structure of DNA
• 1960s: Werner Arber Discovered restriction enzymes
• 1965: Disovery of RNA synthesis by RNA polymerase
• 1967: Marshall Nirenberg and Har Gobind Khorana cracked the genetic code
• 1973: Stanley Cohen and Frederick Boyer first to express a designed foreign gene in a host organism
• 1977 Frederick Sanger developed Sanger sequencing
• 1983: Kary Mullis developed polymerase chain reaction (PCR) to amplify DNA

Pre-Recombinant DNA Era (before 1970s)

• In World War 1 (1914-1918), fermentation technology was used to produce acetone for explosives by fermenting corn starch with Clostridium acetobutylicum
• Scientists discovered in 1901 that beta-cells in the pancreas produce a substance needed to regulate blood glucose
• Insulin extracted and identified from animal pancreas in 1922.
• Purified animal-sourced insulin (bovine, porcine) was the only type available to diabetics until recombinant DNA
• Frederick Sanger determined insulin's primary structure in the 1950s
• 1977/1978: first recombinant human insulin produced.
• First commercially available biosynthetic human insulin was marketed as Humulin®

Modern Biotechnology

• Recombinant DNA (rDNA) technology, also known as genetic engineering, refers to DNA artificially created in vitro with natural or synthetic origins
• Cell culture and fermentation technology are now more advanced
• Hybridoma technology facilitates large-scale production of monoclonal antibodies
• Advances in development of analytical tools and techniques occur (e.g. microarrays, biosensors in diagnostics, monoclonal antibodies for diagnosis/analysis)

rDNA technology impact Biopharmaceutical products

• Overcomes limited source availability
• Allows production of safer biopharmaceuticals
• Provides an alternative to obtain protein-based products other than direct extraction
• Offers opportunities to design desirable mutations in producing engineered protein-based biopharmaceutical products that possesses advantages

Differences between biotechnology-based products and chemical products:

• Traditional Chemical Drugs have molecular weight < 1000 Da, can be chemically synthesized and purified, and chemical modification leads to drastic activity changes
• Traditional Chemical Drugs might have off-target effects

Protein-based biopharmaceutical drugs

• Larger molecular weight, derived from living sources, not easily characterized, more predictable, and has lesser side effects

• Biopharmaceuticals may be a more natural way of treating diseases compared to artificial small molecules and provide a basis for targeted therapy/personalized medicine

• Biopharmaceuticals include recombinant proteins, monoclonal antibodies, and nucleic acid-based products

• Clinical Devices and Diagnostics use biopharmaceuticals

Challenges of using Biopharmaceuticals?

• Immunogenicity may result due to impurities of its non-human origins
• Proteins are susceptible to denaturation and protease degradation
• Phagocytosis can occur if proteins have MW of proteins > 200 kDaltons
• Can be degraded by intracellular degradation systems (proteases, ubiquitin-proteasome system)
• Distribution is limited because the tissue has low permeability/porosity
• Absorption and Disposition can be achieved by IV, IM, SC. R&D efforts to deliver protein products by oral, nasal, transmucosal, transdermal, etc

History of pharmaceutical and biopharmaceutical industry

• 1930s: sulpha drugs and large-scale insulin
• 1940s: penicillin manufacture, Birth of Eli Lilly, Glaxo and Roche etc
• 1940-1980s Drug developments such as tetracyclins, corticosteroids, antidepressants etc
• 1950s: Interferons, interleukins, growth factors, and neurotrophic factors ets are naturally produced in the body
• 1970s-80s: genetic engineering and monoclonal antibody technology appeared.
• 1970s-80s: Genentech developed recombinant human insulin
• 1980s-2000s Biotechnology start-ups became common
• Mid 2006: ~160 biopharmaceutical products had gained marketing potential

Economic impact of the biopharmaceutical industry

• High growth and development with 1 in 4 new drugs are bio
• 160 biopharmaceuticals had gained marketing approval by mid-2006
• Vaccines and monoclonal antibody-based products are the biggest product categories
• Global biopharmaceutical market was >US$70 billion in 2007
• Economic impact: ~3.4 million total jobs created in US economy in 2011
• Gene therapy, T-cell therapy and personalized medicine are up-and-coming