Properties and structure of dextran refers to a polysaccharide composed of glucose as a monosaccharide. Glucose units are connected by glycosidic bonds. According to the type of glycosidic bonds, they can be divided into two categories: α-glucan and β-glucan. Alpha-glucan, also known as dextran, is a natural analog of polyethylene glycol. α-glucan has excellent water solubility and biocompatibility and is widely used in biomedicine. β-glucan is mainly composed of (1→3)-β-glucosidic bonds to form a linear skeleton and is the main component of the cell wall. β-glucan has been used in the production of bioactive nutritional foods to improve glucose metabolism in the body and reduce blood cholesterol levels. Among the glucans, β-glucan has the most physiological activity. In the 1940s, researchers first discovered a substance in yeast cell walls that could enhance immunity. Later, through further research, it was found that the substance in yeast cell walls that has the effect of enhancing immunity is a polysaccharide, β-glucan, and this substance was isolated from baker's yeast. The active structure of β-glucan is composed of glucose units, most of which are connected in β-1,3. It can activate macrophages, neutrophils, etc. to increase the levels of leukocytes, cytokines and specific antibodies, thus stimulating the body's immune system in a comprehensive way. The body is then better prepared to resist diseases caused by microorganisms. β-Glucan can rapidly restore the ability of damaged lymphocytes to produce cytokines (IL-1), effectively regulating the body's immune function. A large number of experiments have shown that β-glucan can stimulate the production of IgM antibodies in the body to improve humoral immunity. This type of glucan-activated cells stimulates the host's non-specific defence mechanism, so its application in tumors, infectious diseases and the treatment of trauma has attracted much attention. β-1,3 glucan, which is extracted by special steps and does not contain endotoxin, has been recognised by the US FDA as a safe substance and can be added to common foods. Many reports show that oral administration of yeast β-1,3 glucan to mice can increase potent antibacterial phagocytosis of peritoneal cells. Yeast glucan is a polysaccharide derived from yeast cell walls that has the effect of enhancing immunity, namely β-glucan. Studies have shown that β-glucan is widely present in various fungi and plants, such as shiitake mushrooms, ganoderma lucidum and oats. Yeast glucan has stronger immune-enhancing activity and can improve blood lipids, anti-radiation and intestinal function.
Figure 1. Dextran-based drug delivery systems.(Hu Q, et al., 2021)
In recent years, it has been discovered that β-glucan can also be used as a gene delivery vector. The main chain of dextran contains abundant hydroxyl groups and has a branched structure of approximately 5%, which ensures its excellent water solubility and facilitates its chemical modification. In addition to being used as a gene carrier, the hydroxyl group of dextran can be used to couple with targeting ligands such as RGD peptide, mannose, and galactose, and can be used to prepare targeted drug delivery systems. Because of its simple structure, good water solubility, high biocompatibility, and nontoxicity and harmlessness to the body, the application of dextran in the field of drug carriers has become one of the research hotspots that has attracted much attention. Drug carriers are systems that can affect the delivery, distribution and release of drugs in the body and accurately transport them to target organs. The drugs contained are usually anti-tumor drugs to solve problems such as their high toxicity, poor water solubility, short half-life, easy degradation in the body, and lack of specific targets. The surface of the dextran molecular structure contains many active hydroxyl groups, which can be chemically modified to form different drug carrier forms such as nanomicelles, nanogels, and prodrugs.
Alternate Names:
Texas Red-Dextran
Texas Red conjugated Dextran
Texas Red-labeled Dextran
Dextran, Texas Red
Dextran conjugate of Texas Red
References:
1. Hu Q, et al. Recent advances in dextran-based drug delivery systems: From fabrication strategies to applications. Carbohydr Polym. 2021, 264:117999.
Preparation and drug delivery of dextran-drug complex
Drug Deliv.
Authors: Huang S, Huang G.
Abstract
Dextran as a drug carrier for inhibiting cancer cells effectively reduces the toxic and side effects of the drug in the biological body. Targeting improves the concentration of active substance around the target tissue, which reduces damage to other heavy organs and other normal tissues. Dextran will be a potential carrier for the delivery of antitumor drugs in the future, which provides the possibility of slow-release chemotherapy and targeted drug delivery. Herein, the preparation and drug delivery of dextran-drug complex were summarized and discussed in detail.
Dextran conjugates in drug delivery
Expert Opin Drug Deliv.
Authors: Varshosaz J.
Abstract
Introduction: Dextran is a family of natural polysaccharides that is widely under investigation for use as polymeric carriers in novel drug delivery systems. The optimal drug delivery (and consequently maximum therapeutic effect) will be accomplished when carrier systems are used mainly for drugs with antitumoral activity, as they increase their blood permanence time, taking advantage of the increased mass that reduces kidney ultrafiltration.
Areas covered: This review summarizes the attempts that have been made in the development of dextran conjugates and their application. The manuscript describes dextran hydrogels, the use of conjugates of dextran in bioadhesive oral delivery systems, colon drug delivery, reduction of ulcerogenicity of drugs, production of micelles, solubilization, long-circulating pharmaceutical carriers as anticancer drug carriers, non-viral vectors, stabilization of enzymes, functionalization of nanomaterials, diagnosis of solid tumors and hyperthermic treatment and liver targeting.
Expert opinion: Dextran conjugation has aided the design of new tailor-made polymers with different molecular weights, shapes, structures and with the functional groups needed for coupling at the desired positions in the chain. Dextran prodrugs are very useful systems for achieving controlled drug release and drug targeting. In particular, various dextran-antitumor drug conjugates enhance the effectiveness and improve the cytotoxic effects of chemotherapeutic agents. Future studies should concentrate on barriers for their clinical use and safety as a drug carrier.
Dextran-polyethylene glycol cryogels as spongy scaffolds for drug delivery
Int J Biol Macromol.
Authors: Pacelli S, Di Muzio L, Paolicelli P, Fortunati V, Petralito S, Trilli J, Casadei MA.
Abstract
Cryogels are a particular type of hydrogels that possess great potential in both fields of drug delivery and tissue engineering. Based on these premises, the goal of this work was to develop a cytocompatible polymeric cryogel, which could be used as a spongy scaffold to promote the delivery of biomolecules. Precisely, the novel formulation was fabricated by combining dextran methacrylate (DEX-MA) and polyethylene glycol dimethacrylate (PEG-DMA) through radical polymerization at a temperature of -15 °C. The swelling, porosity, mechanical properties, and the drug release profile of vitamin B12 from the optimized cryogel were evaluated and compared to hydrogels fabricated at room temperature. The use of the cryo-gelation technique enabled the formation of scaffolds with improved swelling, increased interconnected porosity, and higher mechanical resistance than conventional hydrogels. The cryogels proved to be non-toxic and suitable carriers for the delivery of water-soluble biomolecules. Overall, the novel cytocompatible cryogel formulation could be used for biomedical applications that require the need of a macroporous scaffold for localized delivery of bioactive molecules.
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