Читать книгу Biomolecules from Natural Sources - Группа авторов - Страница 69

Dextran is the generic name of a large family of microbial polysaccharides that are assembled or polymerized outside the cell by enzymes called dextran sucrases. This class of polysaccharides is composed of building blocks (monomers) of the simple sugar glucose [169, 175–177]. It can be found as storage material in yeasts and bacteria. Dextrans are produced by enzymatic conversion of the feedstock sucrose. Most commercial dextran production uses the microorganism Leuconstoc mesenteroides. Cyclodextrins is used as a stabilizer and in edotoxin removal [178]. Dextran polymers have some medical applications. Dextrans were used for wound coverings, in surgical sutures, as blood volume expanders, to improve blood flow in capillaries in the treatment of vascular occlusion, and in the treatment of iron deficiency anemia in humans and animals.

Chemically modified dextrans such as dextran sulfate [179] have antiulcer and anticoagulant properties. Other modified dextrans such as Sephadex are used extensively in the separation of biological compounds. In the industrial area, dextrans are being incorporated into x-ray and other photographic emulsions. Dextran is used as a food-grade biopolymer, nanoparticles, hydrogel, and in transdermal delivery [180].

Dextran-hemoglobin compounds may be used as blood substitutes that have oxygen delivery potential and can also function as plasma expanders.