tailieunhanh - Innovations in Biotechnology Part 6

Tham khảo tài liệu 'innovations in biotechnology part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Polymers in the Pharmaceutical Applications - Natural and Bioactive Initiators and Catalysts in the Synthesis of Biodegradable and Bioresorbable Polyesters and Polycarbonates 141 A cyclosporine A - branched and cyclic oligopeptide composed of 11 amino acids is an important macromolecular immunosuppressive drug Markiewicz Kwiatkowski 2001 Zejca Gorczyca 2002 . Cyclosporine A selectively inhibits lymphocytes T function thus is widely used as an immune barrier tolerance agent in the transplantology. Macromolecular inhibitors that absorb the cholesterol from the intestines are also known form them insoluble in water polymers which produce complexes with the bile acids. To this polymer group belongs copolymer of divinylbenzene and styrene substituted with quaternary trimethylammonium group and copolymer of diethyltriamine and epichlorohydrin Zejc Gorczyca 2002 . A heparin obtained from the animal tissues mainly livers and lungs Zejc Gorczyca 2002 is next example of the natural polysaccharide used as the therapeutic agent. The heparin effects on the all blood clotting phases. Usually is used to treat arterial embolism and thrombosis heart failure and before surgical operations. A very important group of the biomedical polymers is macromolecular blood substitutes. They are accountable for the regular osmotic pressure and viscosity closed to the osmotic pressure and blood viscosity usually used in the anaphylactic shock heart failure intoxication burns toxic diarrhoea embolic-thrombotic complications as well as microcirculation impairment. A polyvinylpyrrolidone was the first synthetic polymer used as the blood substitutes. Its solutions were mainly used to treat the shock after the burns and in the case when the blood transfusion was not indicated Janicki et al. 2002 Florjanczyk Penczek 1998 Zejc Gorczyca 2002 . Likewise the solutions of polyvinyl alcohol have found the applications as the blood substitutes. However they were withdrawn from the list of the blood .