The antithrombotic effect of dextran is mediated through its binding of erythrocytes, platelets, and vascular endothelium, increasing their electronegativity and thus reducing erythrocyte aggregation and platelet adhesiveness. Dextrans also reduce factor VIII-Ag Von Willebrand factor, thereby decreasing platelet function. Clots formed after administration of dextrans are more easily lysed due to an altered thrombus structure (more evenly distributed platelets with coarser fibrin). By inhibiting α-2 antiplasmin, dextran serves as a plasminogen activator, so possesses thrombolytic features. Outside of these features, larger dextrans, which do not pass out of the vessels, are potent osmotic agents, thus have been used urgently to treat hypovolemia. The hemodilution caused by volume expansion with dextran use improves blood flow, thus further improving patency of microanastomoses and reducing thrombosis. Still, no difference has been detected in antithrombotic effectiveness in comparison of intra-arterial and intravenous administration of dextran. Dextrans are available in multiple molecular weights ranging from 3 kDa to 2 MDa. The larger dextrans (>60,000 Da) are excreted poorly from the kidney, so remain in the blood for as long as weeks until they are metabolized. Consequently, they have prolonged antithrombotic and colloidal effects. In this family, dextran-40 (MW: 40,000 Da), has been the most popular member for anticoagulation therapy. Close to 70% of dextran-40 is excreted in urine within the first 24 hours after intravenous infusion, while the remaining 30% are retained for several more days. Other medical uses
Dextran is used in some eye drops as a lubricant.
Solutions of fluorescently-labelled dextran can be perfused through engineered vessels to analyze vascular permeability
Dextran is used to make microcarriers for industrial cell culture
Orally-administered dextran sodium sulphate is used to induce colitis in animal models of inflammatory bowel disease. Side effects
Although relatively few side effects are associated with dextran use, these side effects can be very serious. These include anaphylaxis, volume overload, pulmonary edema, cerebral edema, or platelet dysfunction. An uncommon but significant complication of dextran osmotic effect is acute kidney injury. The pathogenesis of this kidney failure is the subject of many debates with direct toxic effect on tubules and glomerulus versus intraluminal hyperviscosity being some of the proposed mechanisms. Patients with history of diabetes mellitus, chronic kidney disease, or vascular disorders are most at risk. Brooks and others recommend the avoidance of dextran therapy in patients with chronic kidney disease. Research
Efforts have been made to develop modified dextran polymers. One of these has acetal modified hydroxyl groups. It is insoluble in water, but soluble in organic solvents. This allows it to be processed in the same manner as many polyesters, like poly(lactic-co-glycolic acid), through processes like solvent evaporation and emulsion. Acetalated dextran is structurally different from acetylated dextran. As of 2017 several uses for drug delivery had been explored in vitro and a few had been tested in animal models. See also
Pentoxifylline

References
External links
Resource on dextran properties and structure of dextran polymers
Dextrans at the US National Library of Medicine Medical Subject Headings (MeSH)