Erythropoietin-based treating agents are often used for therapy of anemia, caused by various severe diseases. However, these treating agents have strong side effects. Russian medics know how to treat erythropoietin in order to maintain its efficiency, but eliminate unwanted side effects.

Erythropoietin is a hormone, which is responsible for increasing amount of erythrocytes and concentration of hemoglobin in blood. Since it is a protein, it cannot be taken orally, because it is broken down in the stomach and loses its properties. To avoid digestive breaking down of erythropoietin, medics usually prescribe it as injections, which lead to powerful response of an immune system.

However, Russian medics (Science and Research Institute of Pharmacology of Siberian branch of Russian academy of sciences) found out that immobilization of proteins on polyethylene glycol, a low-molecular-weight organic compound, protected these proteins from digestive enzymes and made them suitable for swallowing. Other advantages of immobilized proteins are prolonged effectiveness and less significant irritation of an immune system.

 

 

Immobilization of erythropoietin is performed by means of electron-beam synthesis technology with directed flow of accelerated electrons. The technology is based upon electron accelerators, which generate directed flow of accelerated electrons with energies, reaching several mega electron volt, and give information about radiation time and dose of radiation, absorbed by an object. When biologically active molecules get radiated with directed flow of accelerated electrons together with polyethylene glycol, they bind together by means of strong covalent bonds.

Immobilized erythropoietin doesn’t cause any allergy and resists digestive enzymes successfully. Researchers have checked whether the protein’s biological activity remained the same. The experiments were conducted on mice, which were made anemic by means of an intraperitoneal injection of carboplatin, known to suppress production of blood cells in bone marrow. Anemic mice received immobilized erythropoietin either orally, or subcutaneously. Another group of mice received injections of ordinary erythropoietin. Mice of control group were treated by simple physiological solution. Monitored parameters were blood cell composition and bone-marrow hemopoiesis.

Carboplatin reduced amount of erythrocytes and hemoglobin in mice’s blood, and concentration of own erythropoietin also decreased. All erythropoietin-containing agents were a successful treatment. Ordinary erythropoietin acted faster, and the effect was much more pronounced compared to immobilized protein. Immobilized erythropoietin, absorbed in gastrointestinal tract, didn’t lose its activity and was also effective.

Proteins, conjugated with polyethylene glycol, were demonstrated to have extremely low toxicity, and that is why they can be used as many times as required without a risk of developing side effects or complications. All this gives us a hope that immobilized erythropoietin is a promising tool for future medicine.