Sodium alginate is a sodium salt of polyanionic alginic acid. It is a natural high molecular polysaccharide polymer extracted from natural brown algae. It has the advantages of wide source, low price, good biocompatibility, and degradability. Contains multiple hydroxyl and carboxyl functional groups, so it can react with a variety of divalent or trivalent cations to form hydrogels, and is widely used in biomedical fields such as cell engineering, drug sustained release, and medical dressings. When sodium alginate microspheres are applied to the fields of drug loading, controlled release, and interventional therapy, the control of particle size and morphology of the microspheres is particularly important. For large-sized microspheres ranging from…

Xanthan gum, also known as yellow gum, is white or light yellow powder. In 1952, it was isolated and extracted from the pathogenic strain of Xanthomonas campestris by the northern laboratory of the United States. After in-depth research, it was found that xanthan gum has excellent rheological properties and can partially or completely replace other gloea. Since then, xanthan gum has been extensively studied. Xanthan gum was discovered in 1954, and it has been industrialized for less than 70 years since 1964. It has become one of the most widely used biological gums in the world, and has been used in food, petroleum, and pharmaceutical fields. Xanthan Gum Structure Xanthan…

Pectin is a hydrophilic vegetable gum. Widely present in the fruits, roots, stems and leaves of higher plants, it is a component of the cell wall. The pectin content of different plants or different parts of the same plant varies greatly. So far, only a few plants with high pectin content have been found and used as raw materials for industrial production, mainly citrus peels, sunflower trays, and sugar beets. Pectin is the general term for protopectin, pectin and pectic acid. Protopectin is insoluble in water and only exists in the cell wall; pectin is soluble in water and exists in the cell juice; pectin acid is slightly soluble in…

Carbon dots (CDs) are a new type of zero-dimensional fluorescent nanomaterials with a size of less than 10 nm, which are composed of a graphitized sp2 carbon core and a shell containing abundant groups such as amino groups, ether groups, carbonyl groups, and hydroxyl groups on the surface, has the advantages of easy preparation, low toxicity, stable optical properties and no photobleaching. Since its discovery in 2004, the preparation, luminescence mechanism and application of CDs have been the hotspot of research. CDs preparation methods are divided into top-down and bottom-up methods, covering electrochemical oxidation, laser ablation, hydrothermal, pyrolysis, and microwave methods. Hydrothermal and microwave methods are favored by simple and…

Biodegradable polymers are most often referred to as “biopolymers” because most of these polymers are derived from various natural sources. There are few in the list of biodegradable biopolymers in nature. PLA, PHA and starch are the most commonly used biopolymers that have minimal or minimal impact on the increasing environmental carbon footprint. However, biodegradability is a characteristic of polymers that is independent of their origin and can be altered after tuning at the molecular level. Therefore, some polymers are produced from petroleum feedstocks but are biodegradable. Therefore, in addition to naturally derived biopolymers, there are also petroleum-based biodegradable biopolymers. Natural Biopolymer Natural biopolymers are natural polymers produced by living…

Heparin, also known as standard heparin or unfractionated heparin, is a linear polysaccharide consisting of 1-4 linked disaccharide repeat units of uronic acid and glucosamine residues. Heparin was discovered nearly 100 years ago and has been used clinically as a blood anticoagulant since 1935. This is due to its ability to bind to the antithrombin(serine protease inhibitor), causing the inhibitor to inactivate thrombin. How to Get Heparin? Heparin is a naturally occurring polysaccharide which contains a highly sulfated glycosaminoglycan framework. It is found in animal tissues in form of heparin sulphate. Unfractionated heparins are usually isolated from natural tissues such as pig intestine or bovine lung, with an average molecular…

Sucrose is a disaccharide with a unique structure. It is a non-reducing sugar formed by removing a molecule of water from the glycoside hydroxyl group of a molecule of α-D-(+)-glucopyranose and a molecule of β-D-(-)-fructofuranose. During the hydrolysis process, the specific optical rotation of sucrose gradually changes from dextrorotatory to levorotatory, so the hydrolysis of sucrose is also commonly referred to as a conversion reaction. There are 8 chemically active hydroxyl groups and glycosidic bonds in the sucrose molecule, through which these groups can theoretically undergo oxidation, reduction, decomposition, esterification, polycondensation, etherification, substitution, degradation, etc. with other compounds or itself. This reaction provides the possibility to form a wide variety…

Glucosamine is a natural component of cartilage and is widely used as an over-the-counter nutritional supplement to reduce the pain and cartilage loss of osteoarthritis. Glucosamine is usually taken in combination with chondroitin, which is a glycosaminoglycan that also exists in cartilage. Glucosamine is an amino sugar and an important molecule in the biochemical pathway of glycosylated protein and lipid synthesis. It is also the main component of keratin sulfate and hyaluronic acid present in articular cartilage and synovial fluid. Both glucosamine and chondroitin are reduced in osteoarthritis. Clinically, active supplementation of glucosamine and chondroitin can relieve the symptoms of arthritis. Therefore, it is widely used to treat osteoarthritis and…

Dextran is a polysaccharide comprised of d-glucopyranose (d-glucose) repeating units linked through glycosidic linkages. It is biocompatible, biodegradable, and presents antithrombotic and anti-inflammatory properties. Dextran functional hydroxyl (–OH) groups offer an easy point for chemical conjugation with other materials. As an example, dextran can be modified with hydrophobic moieties in order to form dextran-based amphiphiles. These amphiphilic materials can encapsulate poorly water-soluble chemotherapeutics through hydrophobic interactions and self-assemble into nanocarriers. What Are the Chemical Structure and Properties of Dextrans? Dextran consists of α(1,6)-linked glucan with side chains attached to the C-3 position of the backbone (Figure 1). It is synthesized from sucrose by certain lactic acid bacteria, such as leuconostoc…

Polylactide (PLA), also the polylactic acid, is the biodegradable hydrolyzable aliphatic semicrystalline polyester that can be produced through the direct condensation reaction of its monomer, lactic acid, as the oligomer, and also by a ring-opening polymerization of the cyclic lactide dimer. Is Polylactic Acid Natural? PLA is a biodegradable, biocompatible, and renewable thermoplastic polyester. The monomer lactic acid (LA) of PLA is derived from natural sources, which is produced using bacterial fermentation of corn, sugarcane, potatoes, sugar beet pulp, and other biomass. What Are the Characteristics of Polylactide? PLA is a very useful material to be used as a replacement for petroleum-based polymers because of its good mechanical properties and…