What You Need to Know About Dextran

What is Dextran?

Dextran is a complex branched polysaccharide composed of multiple glucose molecules linked predominantly by α-1,6 glycosidic bonds, with occasional α-1,3 linkages. It is produced by certain bacteria, such as *Leuconostoc mesenteroides* and *Streptococcus mutans*, through the fermentation of sucrose. Dextran's molecular weight can vary significantly, ranging from a few thousand to several million Daltons, which influences its physical and chemical properties.

Dextran is highly soluble in water, forming viscous solutions, and is known for its ability to retain moisture and stabilize proteins. These properties make it a versatile compound with numerous applications across various fields, including medicine, biotechnology, and industry.

For more details about dextran chemistry, please read the blog “Dextran chemistry & properties”.

What are the available forms of dextran?

Dextran is available in several forms, depending on the intended application, molecular weight, and modification level. Here’s a breakdown of the main available forms of dextran.

Dextran is available in a range of defined molecular weights, which influence solubility, viscosity, and biological behaviour.

Dextran can be chemically modified to enhance functionality.

History of Dextran

Dextran's story began in 1861, when Louis Pasteur first observed a viscous substance produced during wine fermentation and identified it as a microbial fermentation byproduct1. A few years later, in 1869, German chemist Carl Scheibler studied the material in greater detail and coined the name "dextran", recognising its resemblance to the starch derivative dextrin2. At the time, dextran was regarded mainly as an unwanted byproduct in sugar processing and winemaking because of the sticky, viscous texture it produced.

Dextran's significance changed dramatically during the 1940s, when a team of Swedish scientists led by Anders Grönwall and Björn Ingelman discovered that bacterial dextran could serve as a blood plasma substitute – an unexpected finding made while investigating contaminations in sugar beet juice. Working with Pharmacia, they developed the first clinical dextran solution, and in 1947 the company launched Macrodex®, the world's first dextran-based plasma expander. Meanwhile, in the United States, chemist Allene R. Jeanes pioneered a method to mass-produce dextran via fermentation, which the U.S. Army deployed as a life-saving blood volume expander during the Korean War3. Dextran solution could be sterilized, stored without refrigeration, and contained no blood products – advantages that made it an invaluable emergency substitute for blood plasma on the battlefield3. By the early 1950s, dextran infusions were credited with significantly improving survival of wounded soldiers, firmly establishing dextran as an important medical polymer.

Over the following decades, advances in biotechnology revealed dextran's remarkable versatility. In 1959, Pharmacia introduced Sephadex® (short for Separation Pharmacia Dextran), a cross-linked dextran gel that revolutionized biochemical chromatography by allowing researchers to separate molecules by size4. Chemists also developed various dextran derivatives (e.g. diethylaminoethyl–dextran and carboxymethyl–dextran) to tailor its properties – adjusting its solubility, charge, or reactivity for specific uses in medicine and research. By the late 20th century, dextran was found in everything from laboratory cell-separation media and organ preservation solutions to controlled drug-release systems, capitalizing on its biocompatibility and versatile chemistry.

Today, dextran is recognised as one of the most versatile carbohydrate polymers used in the life sciences. Manufacturers such as Pharmacosmos produce pharmaceutical-grade dextrans and customised derivatives that support applications across pharmaceuticals, biotechnology, medical devices and advanced therapies. From an unexpected fermentation byproduct discovered in 19th-century wine to an essential material in modern medicine and biotechnology, dextran has evolved into a cornerstone of scientific and pharmaceutical innovation.

Benefits and Key Considerations

Benefits

1. Biocompatibility: Dextran is non-toxic and biocompatible, making it suitable for medical and pharmaceutical applications.

2. Versatility: Its ability to form gels and stabilize proteins makes it useful in various formulations.

3. Moisture Retention: Dextran's hygroscopic nature helps in maintaining moisture, which is beneficial in cosmetics and pharmaceuticals.

4. Blood Volume Expansion: Dextran solutions can be used as plasma expanders in medical emergencies.

Key Considerations

1. Rare Hypersensitivity Reactions: Historically, some clinical dextran products have been associated with rare hypersensitivity or anaphylactoid reactions, particularly in intravenous applications. Although modern purification methods and clinical practices have significantly reduced this risk, regulatory evaluation and application-specific assessment remain important.

2. Viscosity at Higher Concentrations: High-molecular-weight dextrans can increase solution viscosity, which may influence handling, filtration, mixing, or injectability in certain formulations.

3. Analytical Complexity: Characterising polysaccharides such as dextran can be analytically more complex than working with small molecules, often requiring specialised methods to assess molecular weight distribution and structural characteristics.

Use Cases of Dextran

Medical Applications

1. Blood Volume Expander: Dextran solutions are used as plasma expanders and as a means of parenteral nutrition to replace lost blood in emergency situations where replacement blood is not available. It also provides an osmotically neutral fluid that, once in the body, is metabolised by cells into glucose and free water.

2. Organ Preservation: Dextran is used in organ preservation solutions to maintain tissue viability during transplantation.

3. Cryopreservation: It helps protect cells and tissues from damage during freezing and thawing processes.

4. Cell Therapies: Dextran is used in cell therapies for cryoprotection, cell surface modification, drug delivery, and preventing cell clumping, enhancing overall cell viability and processing.

Biotechnology and Laboratory Uses

1. Cell Culture: Dextran is used as a supplement in cell culture media to enhance cell growth and viability.

2. Blood Cell Separation: It facilitates the separation of red blood cells from other cells and components in the blood.

3. Protein Stabilization: The dextran molecule is known to benefit the structural stability of freeze-dried products and can support protein stability as well as the recovery of enzyme activity after freeze-drying.

Pharmaceutical and Therapeutic Uses

1. Drug Delivery Systems: Dextran derivatives are used to create drug delivery systems that allow controlled release of therapeutic agents.

2. Cancer Therapies: Dextran-based nanoparticles are being explored for targeted cancer therapy.

3. Vaccines: Dextran is used in vaccines is as stabilizers or excipients to maintain integrity and potency during storage and transportation, and they can provide protection against degradation while maintaining the proper pH and preventing the aggregation of vaccine components. In addition, dextrans can be used as carriers or delivery systems for vaccine antigens.

4. Lyophilization: It is used in the freeze-drying process to stabilize pharmaceuticals.

Industrial and Research Applications

1. Food Industry: Dextran is used as a food additive to improve texture and moisture retention.

2. Cosmetics: It is used in skincare products for its moisturizing properties.

3. Research: Dextran is used in various research applications, including chromatography and as a standard in molecular weight determination.

Recent Developments

Recent advancements in nanotechnology and polymer chemistry have led to the development of novel dextran derivatives with enhanced properties. These include dextran-based hydrogels for wound healing and smart drug delivery systems that respond to environmental stimuli. Research is also ongoing to explore the use of dextran in regenerative medicine and as a scaffold for tissue engineering.

The Future of Dextran

The future of dextran is exceedingly promising, with research pushing its applications far beyond traditional uses in medicine and biotechnology. Scientists are developing novel dextran derivatives with tailored functionalities (e.g., oxidized dextran, acetylated dextran, and carboxymethyl dextran) to enhance performance in specific contexts. In drug delivery, dextran-based nanocarriers are anticipated to revolutionize therapy by enabling highly targeted and stimuli-responsive release of therapeutics, thereby improving treatment precision and efficacy5. This approach is especially impactful in cancer therapy—dextran–drug conjugates and nanoparticles are being designed to deliver anticancer agents more selectively to tumors, boosting efficacy while minimizing side effects6. Personalized medicine could also benefit from dextran: future dextran nanoparticles may be custom-tailored to patients’ genetic profiles, allowing individualized drug delivery for better clinical outcomes5. Additionally, dextran’s role in diagnostic imaging is set to expand; for example, dextran-coated iron oxide nanoparticles and quantum dots have already improved biocompatibility and stability of contrast agents5, and ongoing work on dextran-based contrast nanoparticles promises more sensitive and precise imaging tools5. In the realm of regenerative medicine, dextran’s biocompatibility and ability to form hydrogels make it ideal for creating advanced tissue scaffolds, supporting cell growth and tissue repair5. Researchers are even leveraging dextran for smart biomaterials and biosensors – dextran-based hydrogels and films that respond to biological or chemical signals could transform diagnostics and responsive drug delivery technologies5. Beyond the biomedical sphere, dextran is finding new eco-friendly applications: its renewable, microbial production and biodegradability align with the demand for sustainable materials. Environmental innovations include dextran-derived water purification systems and biodegradable polymer alternatives that might help reduce plastic waste5. Overall, dextran’s extraordinary adaptability and ease of functionalization position it as a critical biopolymer for future advancements across medicine, technology, and environmental science5.

Recent literature underscores these trends, highlighting the development of pH-responsive dextran polymers like acetalated dextran (Ace-DEX) for controlled drug release in acidic tumor microenvironments, as well as comprehensive reviews on dextran-based hydrogels and nanocarriers for drug delivery, imaging, and tissue engineering. These developments suggest that as the demand grows for biocompatible and sustainable materials, dextran will play an increasingly important role in innovative therapies and industrial applications.

FAQ

What is Dextran?

Dextran is a complex polysaccharide composed of glucose molecules, used in various medical, pharmaceutical, and industrial applications due to its biocompatibility and versatility.

What is Dextran Used For?

Dextran is used as a blood volume expander, in organ preservation, cryopreservation, drug delivery systems, cancer therapies, vaccines, and more.

What Type of Solution is Dextran?

Dextran forms a colloidal solution in water, which can be used as a plasma expander or in other medical and industrial applications.

Is Dextran Safe?

Dextran is generally considered safe and biocompatible, though rare allergic reactions may occur.

How is Dextran Produced?

Dextran is produced by the fermentation of sucrose by certain bacteria, followed by purification processes to obtain the desired molecular weight and purity.

By understanding the diverse applications and benefits of dextran, researchers and industry professionals can continue to innovate and expand its use in various fields.

What is the Difference Between Dextran and Inulin?

Dextran is a glucose-based microbial polysaccharide, widely used in medical and biotech fields.

While Inulin is a fructose-based plant-derived polysaccharide, commonly used in nutrition and gut health.

Is Dextran and Dextrose the Same Thing?

Dextran 40 is a linear glucose polymer (polysaccharide) chemically designated (C6 H10 O5) while Dextrose, USP is chemically designated D-glucose monohydrate (C6 H12 O6 • H2O), a hexose sugar freely soluble in water.

References:

1. Pasteur, L. (1861). On the viscous fermentation and the butyrous fermentation. Bulletin de la Société Chimique de Paris, 11, 30–31

2. Caligur, V. (2008). “Dextran and Polysaccharides Overview.” BioFiles, 3(10), 17. (MilliporeSigma)

3. O’Brien, D. (2016). A Root Beer-Based Discovery that Saved Lives | USDA Blog - An official website of the United States government

4. Sephadex – Wikipedia (Accessed 2025-08-28)

5. Rajendran, A.T et al. Natural Food Components as Biocompatible Carriers: A Novel Approach to Glioblastoma Drug Delivery, Foods, 2024, 13, 2812.

6. Khan M.S. et al. Advancements in dextran-based nanocarriers for treatment and imaging of breast cancer, International Journal of Pharmaceutics, 2023 Aug 25:643:123276.