BIOTECHNOLOGY - Inshyna N.M. - 2009

CHAPTER 4. MEDICAL BIOTECHNOLOGY

Production of Human Recombinant Proteins

Developing and introducing a new drug into clinical practice requires a significant amount of time (10-12 years) and financial investment ($600 million). It is well known that completely safe drugs do not exist. In the United States alone, 100,000 people die annually from adverse drug reactions. The WHO has established a database to track adverse drug events, and drug safety centers have been established in Western Europe, the USA, Japan, and China.

Introduction/32.html">Genetic Engineering Methods make it possible to produce unique therapeutics that are less toxic than traditional ones. Researchers are focusing particularly on developing effective treatments for geriatric conditions, such as Alzheimer's disease, Parkinson's disease, Cancer, chronic renal failure, diabetes, Osteoporosis, and cardiovascular diseases (strokes, Heart attacks). Most biotech drugs are Proteins synthesized using Recombinant DNA technology.

The primary hosts for producing recombinant proteins are the Yeast Saccharomyces cerevisiae. Examples of products derived using

recombinant DNA technology are presented in Table 4.2.

Class="center">Table 4.2

Drugs Produced Using Recombinant DNA Technology

Enzymes constitute a special group of recombinant proteins. Enzymes used in clinical diagnostics or as therapeutic agents must be highly purified. Immobilized Proteolytic Enzymes (Chymotrypsin, Trypsin, collagenase) are successfully used to treat purulent lung and pleural diseases, trophic ulcers, and radiation-induced skin ulcers. Streptokinase and urokinase are employed to treat cardiovascular diseases.

A novel trend in medicine is The Development of efficient methods for delivering enzyme therapeutics to target Tissues. Microcapsules are used as carriers for immobilized enzymes. With this administration method, the enzyme does not contact Body Fluids and tissues, is not degraded by proteases, and does not trigger an immune response. An advantage of microcapsules is the possibility of implanting them directly at a target site, such as near a tumor (where the microcapsule metabolizes compounds required for tumor tissue growth, thereby arresting its expansion).

Microcapsules are also utilized in artificial Kidney devices. A microcapsule-based artificial kidney requires a dialysis Column with a volume of only 30 mL, which operates 100 times faster than conventional apparatuses.

Intensive research is being conducted on The properties of microcapsules whose walls consist of Erythrocyte membranes. The Contents of the red Blood Cells are removed, and the resulting erythrocyte "ghost" is filled with an enzyme. Such microcapsules are entirely compatible with

the patient's body. Significant progress has been achieved in treating asparaginase-dependent tumors using asparaginase encapsulated in erythrocyte ghosts.

In addition to microcapsules, micelles or Liposomes are used to deliver enzyme-based drugs. Cells internalize liposomes via phagocytosis, thereby delivering the enzymes directly into the Cytoplasm.

In the early 1990s, medicinal products based on viable microorganism cells were developed. By 1992, over 50 strains had been investigated, and the effects of their BIOLOGICALLY ACTIVE SUBSTANCES explored. Saprophytic microorganisms capable of living in Symbiosis with the normal intestinal microflora are introduced into The Human Body. The biologically active compounds synthesized by these Bacteria regulate biochemical processes within the body. Strains of Bacillus subtilis are used to treat bacterial infections of the intestines and respiratory tract, as well as allergies (e.g., the drug "Bactisubtil" for diarrhea). E. coli strains are used to treat intestinal disorders.