Special Issue "Marine Chitin and Chitosan"
A special issue of Marine Drugs (ISSN 1660-3397).
Deadline for manuscript submissions: closed (28 February 2010)
Chitin can be interpreted as the most abundant organic compound of nitrogen. Current sources are the crustacean shells isolated as by-products of canning / freezing operations in marine food factories. Mechanical peeling and enzyme inactivation are pre-requisites for treating the chitin-bearing biomass. Immediately after isolation, chitin is transformed into chitosans of various grades. Chemical, physical and enzymatic deacetylation methods are available for the production of chitosan, the sole abundantly accessible cationic polysaccharide. Manipulation of the molecular weight leads to water-soluble chitosans: the randomly 50 % deacetylated, and the partially depolymerized chitosans are water-soluble. Advanced water-soluble modified chitosans are also available, as well as new solvent systems. Purification methods from proteins, carotenoids and inorganics enable to produce chitosans of technical, food, pharmaceutical and medical grades, that are officially recognized as safe in a large number of countries. The industrial production of N-acetylglucosamine and glucosamine is based on the depolymerization of chitosan from marine crustaceans. Due to different crystallinity, chitosan obtained from squid chitin is more prone to chemical modification because the nanofibrillar structure of chitin and chitosan has a certain technical significance. Chitosans in novel physico-chemical forms include composites, electrospun nanofibers, polyelectrolyte complexes, blends with neutral polysaccharides (cellulose, starch...), silylated and otherwise cross-linked chitosans, metal ion chelates, and films for marine food protection. Chitin and chitosan are not drugs sensu stricto, but exhibit peculiar characteristics that recently qualified them in the biomedical field, for example as carriers for drug delivery, chitosan being the best DNA vector for gene therapy. Chitosan exerts immuno-stimulating effects, and it is not seen as a foreign body by human cells. The antimicrobial activity of chitosans has been elucidated for numerous bacteria and some fungi. This special issue is expected to encourage a wider exploitation of the marine chitin resources, and the scaling-up of certain applications, particularly in the pharmaceutical area.
Prof. Dr. Riccardo A.A. Muzzarelli
- quality assessment
- drug carriers