How Are Biotechnology Medicines MadeWhile it might be thought of as a new branch of science and technology, biotechnology is actually quite old. Given that its accomplishments include the domestication of plants and animals, it’s practically synonymous with civilization itself. The use of biotechnology also has a long history in the creation of medicines, but most of this history has been marked by fascinating methods of discovery. Over the last couple of centuries, a more systematic approach has been devised. Thanks to increased understanding of genetics and microbiology, biotechnology has been harnessed to create otherwise impossible drugs or provide a more effective way of generating existing medications.
Biotechnology has become very sophisticated in the field of medicine lately, but it also has precedents in the past. Nearly all cultures throughout the world have been aware of the healing powers of herbal plants since prehistoric times, and these plants have been domesticated along with food crops to supply a reliable source of treatment for ailments. There are also examples of antibiotics being created from soybean curd mold in China as far back as 500 B.C. In all of these cases, the usefulness of these products was discovered through trial and error. No one knew why these materials did what they did.
An explosion of discoveries in the 19th and 20th centuries ushered in the modern era of biotechnology. Scientists were now getting a full understanding of how biochemical processes took place in the body. Learning about everything from enzymes to hormones to vitamins meant medical researchers could deliberately design drugs to target specific problems. The new information also showed them how to go about producing these medications by tapping into natural biological processes. Ultimately, the discovery of the very instructions for life, DNA, provided a powerful tool for manufacturing biotech medicines.
The Basic Procedure
The discovery of the hormone insulin and its effectiveness in treating diabetes offers an example of how the basic rules of biotech medication development were formulated. The main steps consist of determining the biologic source of a desired medication, mass-producing the source, extracting and purifying the medication, and preparing the medication for use. In the case of insulin, experiments dating back to the early 1880s in Germany showed how damage to the pancreas resulted in a buildup of glucose in the bloodstream. This condition, diabetes, was found to be reversible when insulin extracted from healthy pancreases is administered to a victim of the condition. Two Canadian researchers, Dr. Frederick Banting and Charles Best, discovered that fluid drawn from a particular feature of the pancreas, the islets of Langerhans, contained the insulin capable of lowering glucose levels in diabetics. Through subsequent studies, it was learned that insulin produced by pig pancreases caused fewer side effects than that from alternative sources. Because there was already a thriving market for hogs, large numbers of pancreases were available. The final step involved further refinements of the insulin to increase its effectiveness by adding the protein protamine that provided the insulin with a slow-release quality.
DNA manipulation plays an increasingly vital role in biotech medicine development, and insulin production was one of the earliest endeavors to make use of this technology. While strong measures were used to ensure the purity of pig-derived insulin before the 1980s, it was still not exactly identical to human insulin. The slight difference in protein structure was enough to trigger an allergic reaction in diabetics that caused the insulin to become less effective over time. Producing insulin through gene splicing removes the threat of rejection since the resulting insulin is purely human in its structure.
Modifying the Steps
The introduction of genetic engineering has altered the first step in creating biotech medicine. Instead of simply identifying a biological entity that produces the desired substance, an organism is literally created for this purpose. Here, E.coli bacteria has synthesized DNA sequences that match the structure of human insulin proteins inserted into it. This engineered bacteria is then placed in a bioreactor along with growth nutrients and fermented at the proper temperature and acidity level. The result is a doubling of bacteria about every 20 minutes. When the targeted batch size is achieved, the altered E.coli is removed and chemically treated to break down its DNA into individual components. Using various technologies such as chromatography, the strands of insulin proteins are separated out from the original E.coli DNA. Finally, as with the older method of producing insulin, additional agents are added to the insulin to give it qualities like slow absorption in the blood stream.
The example of producing human insulin demonstrate that the steps involved in creating modern biotech medicines are more complicated than those used to extract small molecule compounds from plant and animal sources in the past. While insulin production offers a basic guide to the procedure, as the size and complexity of proteins needed for medicines increase, the controls needed to successfully manufacture drugs become tighter. Drugs like rituxan or interferon demand more precise controls than even insulin. Seemingly tiny changes in temperature or pH balance in the fermentation tank holding the modified organisms can alter the shape of the desired proteins and render them useless. For these more sophisticated pharmaceuticals, engineered animal cells are used instead of bacteria.