Dextrans are used in many applications as platelet aggregants, plasma volume extenders, osmotic pressure regulators, stabilizers, organ separation media, matrix components, copolymers, microcarriers, binding agents, viscosity modifiers, antithrombotics, lubricants and physical structure components. They may be used as long hydrophilic spacer arms to improve the performance (freedom of movement) of conjugated/bound proteins. Dextrans may be derivatized for use in biosensor systems.
Dextrans of less than 60,000Da are generally considered low molecular weight dextrans. Low molecular weight dextrans are often preferred versus high molecular weight dextrans due to their viscosities, aggregation and permeation properties. High molecular weight, water-soluble, dextran polymers have been used in a wide variety of biomedical applications. Dextran (1500-2800), a high molecular weight dextran, may be used to induce blood aggregation and as a high viscosity plasma expander (HVPE).
Use of dextrans as long and hydrophilic spacer arms improves the performance of immobilized proteins acting on macromolecules.
With the exception of the highest MW dextran, D5501 (MW range = 5 million to 40 million), dextrans are very water soluble. Sigma tests the solubility of dextrans at concentrations generally exceeding 30 mg/ml in water. Dextrans are also freely soluble in DMSO, formamide, ethylene glycol, and glycerol. Neutral-aqueous dextran solutions can be sterilized by autoclaving at 110-115oC for 30 to 45 minutes. Dextran can be hydrolyzed by strong acids at high temperatures. The terminal reducing end group of dextran can be oxidized in alkaline solutions.