Glucan is a natural polysaccharide that is widely distributed in cereals and microorganisms and has various biological activities such as immunomodulation, anti-infection, anti-inflammatory and anti-tumor. In addition to its wide range of applications in food, health care products and biomedicine, dextran has great potential as a drug delivery carrier material or ligand. Dextran microparticles or yeast cell wall microparticles are naturally enclosed carriers with internal cavities that can be used to carry and release drug payloads. The biological activity and targeting ability of dextran largely depend on the recognition of dextran structural units by receptors such as Dectin-1 and complement receptor 3, which are widely expressed on mononuclear phagocytes, tree on the cell membranes of protruding cells, neutrophils, and some lymphocytes. Dextran is mainly used as vaccine adjuvants, targeting ligands and carrier materials for various pharmaceutical entities. Research suggests that dextran and dextran microparticles may be useful for the delivery of both small and large molecule drugs, especially for the potential application of drug delivery for the potential treatment of immune-related diseases.
Figure 1. Dextran-based drug delivery systems. (Hu Q, et al.; 2021)
Glucans obtained by different extraction methods have different structural characteristics:
Acid extraction: Glucan can be obtained through acid extraction. This method may lead to changes in the molecular structure of glucan, such as the introduction of acidic groups or the destruction of some sugar chains, thus affecting its biological activity and applicability.
Alkali extraction: Alkaline extraction methods may lead to deacylation or dealdehylation of dextran, thereby changing its structural characteristics, such as the length of sugar chains, distribution of branch chains, etc., which may affect the solubility, stability, properties, and biological activity of dextran.
Enzymatic hydrolysis extraction: The use of enzymatic hydrolysis method to extract glucan may be gentler and can maintain the natural structural characteristics of glucan, such as the ratio of main chain and branch chain, length and branching of sugar chains, etc., which is beneficial to maintaining glucan biological activity and drug delivery properties.
Supercritical fluid extraction: Supercritical fluid extraction can obtain dextran under milder conditions, which is beneficial to maintaining the structure and activity of dextran.
Glucans with different structures have different biological activity characteristics:
Immune enhancement: β-(1,3)-glucan can enhance immune function. For example, β-(1,3)-glucan in licorice polysaccharide (Ganoderma lucidum) has immunomodulatory effects.
Anti-inflammatory: Certain beta-(1,3)-glucans also exhibit anti-inflammatory activity, such as beta-(1,3)-glucan from licorice polysaccharide.
Immunomodulation: β-(1,6)-glucan exists as a side chain in some glucans, which can enhance the immunomodulatory effect, such as β-(1,6)-glucan in yeast glucan.
Anti-tumor: β-(1,3), (1,6)-glucan has anti-tumor activity in some glucans, such as β-(1,3), (1,6) in lentinan)-dextran.
Immunomodulation: Some glucans with special structures may have specific immunomodulatory effects, such as specific β-(1,2)-glucans.
In general, glucans with different structures may exhibit different biological activities such as immunomodulation, anti-inflammation, and anti-tumor. These activities may be affected by the specific bonding methods and side chains in the glucan structure.
Dextran Applications in Drug Delivery
Chemical drug delivery: dextran can be used as a drug carrier to encapsulate chemical drugs, improve the stability and solubility of the drug, achieve controlled release of the drug, and reduce the toxicity and side effects of the drug.
Biological drug delivery: dextran can be used to deliver biological drugs, such as protein drugs, nucleic acid drugs, etc., to improve the stability and bioavailability of these drugs and prolong the action time of the drugs in the body.
Targeted delivery: dextran can achieve targeted delivery by binding to specific receptors, accurately delivering drugs to target tissues or cells, improving the efficacy of drugs and reducing the impact on healthy tissues.
Immunomodulation: Glucan can activate the immune system and enhance the body's absorption and effect of drugs.
Anti-tumor drug delivery: Dextran can be used to deliver anti-tumor drugs, improve the concentration of drugs in tumor tissues, reduce damage to normal tissues, and improve therapeutic effects.
Nanodrug delivery system: dextran can be combined with nanomaterials to construct a nanodrug delivery system, improve the stability and targeting of drugs, and achieve more effective drug delivery.
Antibacterial drug delivery: dextran can be used to deliver antibacterial drugs, such as silver nanoparticles, etc., to improve the antibacterial effect of the drug and reduce the toxicity and side effects of the drug.
References
- Hu Q, et al.; Recent advances in dextran-based drug delivery systems: From fabrication strategies to applications. Carbohydr Polym. 2021, 264:117999.
- Kumari M, et al.; Dextran-based Drug Delivery Approaches for Lung Diseases: A Review. Curr Drug Deliv. 2024 Jan 12. Epub ahead of print. PMID: 38243938.
