Studies on Chitosan, Chitin and Chitooligosaccharides and Their Biomedical Properties

Research in healthcare involves the use of natural resources in the manufacture of pharmaceutical products. Chito-oligosaccharides (CHOS) are described as homo- or heterooligomers of N-acetylglucosamine and D-glucosamine. As a starting material for CHOS production chitin or chitosan can be used. When it comes to the medical field, there are indications that CHOS may be developed and used as drugs against asthma, antibacterial agents, ingredients in wound-dressings and vectors in gene-therapy. The methods of production can rely on enzymatic conversions, chemical methods or combinations of these methods. There is ample literature concerning the biological effects of chitosans, but relatively little is known about the effects of CHOS, and the mechanisms behind observed bioactivities are generally poorly understood. This review is focused on the characterization of chitin and chitosan by presenting the biological properties, and on the enzymatic production of CHOS, and on further separation and purification methods for producing well-defined mixtures and also provides an overview of some of the most promising applications of CHOS.