- Dextran is a complex branched polysaccharide composed mainly of α-(1→6)-linked glucose units with occasional α-(1→3), α-(1→4), or α-(1→2) branch points.
- It is naturally produced by certain lactic acid bacteria, particularly Leuconostoc mesenteroides and Streptococcus species, through the enzymatic action of dextransucrase, which converts sucrose into dextran and fructose. Because of its structural diversity, dextran exhibits a wide range of molecular weights, which influence its physicochemical properties and applications. Its biocompatibility, solubility in water, and ability to form hydrogels make dextran a highly versatile biomaterial in medicine, food technology, and biotechnology.
- In the medical field, dextran has been extensively used as a plasma volume expander during surgery or trauma. Intravenous dextran solutions help restore blood volume by increasing osmotic pressure, thereby improving circulation and preventing shock. In addition, dextran and its derivatives are employed as antithrombotic agents, as they can reduce blood viscosity and inhibit platelet aggregation. Modified dextrans are also used as carriers in drug delivery systems, where they improve solubility, prolong circulation time, and enable targeted delivery of therapeutic molecules. Furthermore, dextran-coated nanoparticles are widely applied in magnetic resonance imaging (MRI) as contrast agents, combining imaging functionality with biocompatibility.
- Dextran’s applications extend into laboratory and biotechnology research. It is a key component in size-exclusion chromatography resins (such as Sephadex), where its controlled crosslinking creates porous matrices for separating proteins, nucleic acids, and other biomolecules. In cell biology, dextran is used to induce cell aggregation or to deliver macromolecules into cells via endocytosis. Fluorescently labeled dextrans are commonly employed as molecular tracers for studying cellular uptake, transport, and permeability.
- In the food and pharmaceutical industries, dextran serves as a stabilizer, thickener, and emulsifier. It improves the texture of baked goods, prevents crystallization in sugar syrups, and enhances the stability of emulsions. As a dietary fiber, dextran also exhibits prebiotic properties, contributing to gut health by promoting beneficial microbiota. Its ability to retain water and form gels has made it useful in low-fat or functional food formulations.
- From a structural and materials science perspective, dextran is valued for its ability to form biodegradable hydrogels. Chemically modified dextrans, such as oxidized or methacrylated forms, are used in tissue engineering and regenerative medicine as scaffolds for cell growth and controlled release systems for bioactive compounds. These hydrogels are attractive because they mimic the extracellular matrix, degrade safely in the body, and can be tailored for mechanical strength or degradation rates.
