?What is chitosan? What is its use

This substance is an amino polysaccharide polymer that is commercially produced from the shell of crab, crayfish and shrimp. By extracting this shell by chemical modification (acetylation) or enzyme, the outer shell of these organisms can be extracted with the help of alkaline substances such as sodium hydroxide. Shrimp is considered the main source of chitosan because it contains 25% to 40% chitin, while crab shell is approximately 15% to 20%.

Chitosan with the chemical formula (C6H11NO4) is obtained from the deacetylation of chitin, which is due to its non-toxicity, high absorption properties, the possibility of decomposition in nature, compatibility with the environment, economic efficiency, and the ability to remove a wide range of colors. and metals, fast kinetics and finally the possibility of preparing many derivatives from it, are of great interest.

Some examples of important applications of chitosan:

Wastewater treatment and water engineering

Due to its polycationic nature, chitosan can act as a coagulant and can also trap heavy metal ions as a chelating agent.

Paper and packaging industries

Biodegradability and its high compatibility with the environment have made chitin and chitosan to be used in the packaging industry as well as recyclable paper.

Chitosan can be easily used in paper factories due to its structural similarity with cellulose. Papers produced from chitosan have a smooth surface and high resistance to moisture, which are very suitable for printing and painting. Also, due to hydrogen bonds between polymer chains, paper is flexible and strong and resists tearing. In addition, chitosan is used in the food packaging industry due to its antimicrobial properties.

Textile Industry

Chitosan as a non-toxic, biodegradable and environmentally friendly natural biopolymer is a suitable option for use in the textile industry, and in addition, the antibacterial property of this type of fiber has led to its use in sportswear, women's clothing, Children and elegant, beautiful, anti-odor and hypoallergenic clothes should be used.

Food industry

Chitosan is used as an additive in meat and dairy products due to its properties such as antimicrobial and antioxidant properties, as well as preventing changes in taste and increasing shelf life.

Also, in food packaging, films produced from chitosan are safe and widely used for food packaging. In addition to having antimicrobial properties, these packages also have good mechanical properties.

agriculture

In order to create a thin coating on foods such as fruits and vegetables, which prevents the spoilage of agricultural products in the form of an anti-bacterial and anti-fungal protective film.

Medicine and biomedicine

Chitosan with appropriate purity is used in drug release and release systems, hemodialysis, artificial skin, medicated linens, enzyme immobilization, contact lenses, eye bandages, orthopedics, surgical thread, dentistry, and agriculture, and in addition, it has other effects. Because the ability to absorb fat, reduce glucose, cholesterol and triglycerides and antimicrobial has also been reported, the low solubility of chitosan has caused limitations in the use of this valuable substance.

Chitosan is so important in different parts of the pharmaceutical industry that it was predicted to be one of the best-selling and most prominent raw materials produced in the world in 2005 and to overshadow the global market. 75% of prepared chitosan will be used for medicine and health. Chitosan has been named as a drug carrier of the 21st century.

Application in medical engineering

Among the expanding applications of chitosan polymer in medical engineering, the following can be mentioned:

Application in wound healing, application in tissue engineering, application in the manufacture of drug carriers in drug release, manufacture of chitosan nanocarriers in the release of anticancer drugs and release of vaccines, gene therapy and bioimaging of vital organs.

Yen, M., Yang, J., Mau, J. 2009. Physicochemical characterization of chitin and chitosan from crab shells. Carbohydrate Polymers. 75(1): 15-21.

Wang, T., Zhu, X.K. , Xue, X.T. , Wu, D.Y. 2012. Hydrogel sheets of chitosan, honey and gelatin as burn wound dressings. Carbohydrate Polymers. 88(1): 75-83.