Chitin potential applications

The a-chitin nanofibrils have lesser safety issues than chemically modified materials such as TEMPO-oxidized a-chitins. As a consequence, potential applications can be expanded to functional foods, life sciences, and medical fields. 

Despite the various potential applications of chitosan, there are several drawbacks. For example, the costs of production often outweigh the economic benefits of its application. Extraction yields for chitosan from waste are generally very low ( 3-5% of raw material) and production is limited by seasonal variations in crustacean harvesting. Also, additional waste streams are created during the alkali deproteinization of chitin during isolation (Ludlow, 2001 Synowiecki and Al-Khateeb, 2003). One interesting... 

Potential applications of scaffolds made from chitosan and chitin nanofibers have been explored in tissue engineering. Chitin and chitosan can be electrospun into nanoscaffolds that could resemble the native extracellular matrix and have improved cytocompatibility for tissue engineering... 

Sandford, P.A. 1989. Chitosan commercial uses and potential applications. In Chitin and Chitosan Sources, Chemistry, Biochemistry, Physical Properties and Applications, eds. G. Skjak-Braek, T. Anthonsen, and P. Sandford, pp. 1-69. England Elsevier Applied Sci. 

Chitin, a p-1,4 polymer of A-acetyl-o-glucosamine (GlcNAc), is the second abundant biopolymer found in nature after cellulose (Muzzarelli 1999). This natural resource is relatively easily accessible, for example, as crab and shrimp shell waste. A-acetyl-chito-oligosaccharides and chito-oligosaccharides have varied biological functions and many potential applications in a wide range of fields (Tokoro et al. 1988, Hirano and Nagao 1989). To obtain enzymes that can be applied... 

A potential application of cuttlebone as filler for NR was reported and study proved that cuttlebone to be a biomass for new reinforcing filler for NR as the cuttlebone particles did not prevent a peroxide crosslinking reaction of NR, and mechanical properties of peroxide crosslinked NR filled with cuttlebone particles were found to be comparable with those of peroxide cross-linked NR filled with commercial CaC03 filler. Presence of chitin on the surface of the cuttlebone particles was speculated to result in a good interaction between cuttlebone particles and NR, which may be ascribed to the mechanical properties of cuttlebone filled NR samples. 

Semi-permeable membranes, such as those used in ultrafiltration, have many potential applications in the food industry. Ishikawa and Nara (1992) pointed out, however that the main problem with these systems was the permeation of the solute used in osmosis into the foodstuff. This could be controlled by the use of a semi-permeable membrane placed in intimate contact with the food, that is, with no free space between the membrane and the food. They investigated the use of a membrane made from a chitosan gel. Chitosan is prepared from chitin, a glycan separated commercially from the shells of crustaceans. Chitosan is both semi-permeable and edible. They postulated that food could, therefore, be coated with a chitosan membrane, thereby eliminating any free space. As yet, chitosan is not permitted as an additive in foods, but this technique may find wide applications in the food industry if chitosan were to be accepted as a processing aid for foodstuffs. 

Chitin is mainly used as a powder and as a precursor to chitosan. However, the unusual aminopolysaccharide structure of chitosan has led to many potential applications. The ease of processing chitosan into shaped articles, coupled with its ease of chemical derivatization, makes it a versatile material. The specificity of chitin and chitosan s structure is also important for many biological applications involving the binding and purification of many proteins. 

Other Matrices. A large number of other matrices have been employed, including starch (33), cross-linked dextrins (34,35), a vinyl maleimide polymer (36), chitin (37), mannan (38), and insolubilized proteins (39). The number of potential matrices is almost limitless, and most of the matrices used for immobilization of enzymes have potential application in bioselective adsorption. Among these are nylon (40), metal oxides (41), maleic anhydride-ethylene co-polymers (42), and polystyrene derivatives (43). Few of these have been used because of their potential for nonspecific adsorption either by charge, as with the metal oxides, or by hydrophobic interactions (as would be the case with polystyrene). The derivatized matrix must be free of nonspecific adsorption. Proper derivatization can eliminate nonspecific adsorption or, as with cyanogen bromide activation, create nonspecific adsorption in matrices having no prior nonspecific adsorption properties. 

The second section contains six chapters emphasizing saccharides and polysaccharides with natural feed stocks derived from sucrose, dextran, cellulose, cotton, xylan, chitin, starch, and bagasse for potential applications as commercial insulation, topical medical applications, fire retardant articles, durable roofing panels, and other building materials. 

PCL, is an important APES with many potential applications in biomedical and environmental fields [144]. This polymer was the first one to be studied in bionanocomposite when in the early 1990s, GianneUs group from Cornell University (Ithaca, NY, USA) started to work on the elaboration of PCL-based nanocomposites by intercalative polymerization [295]. Since then, a vast number of bionanocomposites have been prepared [87]. Several groups used intercalation, master batches, and in situ polymerization of PCL with clays to produce a variety of nanocomposites as can be seen in Table 11.2. Not only clays, but also various types of nanoreinforcements such as cellulose [296] and StNs [297, 298], chitin [299] nanowhiskers, carbon nanotubes [300, 301], and silica nanoparticles [302] have been used to prepare bionanocomposites with PCL. 

The cationic amino polysaccharide chltin is commonly found in nature. Present in many organisms such as fungi, seaweed, protozoa and arthropods. Chitosan a derivative of chitin is of remarkable economic interest due to its functional versatility, with potential application in... 

Chitosan, the most abundant marine mucopolysaccharide, is derived from chitin by alkaline deacetylation, and possesses versatile biological properties such as biocompatibility, biodegradability, and a non-toxic nature. Due to these characteristics, considerable attention has been given to its industrial applications in the food, pharmaceutical, agricultural, and environmental industries. Currently, chitosan can be considered as a potential marine nutraceutical because its remarkable biological activities have been investigated and reported, in order to exploit its nutraceutical... 

Harish Prashanth, . V. and Tharanathan, R. N. (2007). Chitin/chitosan Modifications and their unlimited application potential. Trends Food Sci. Technol. 18,117-131. 

This subject has been of continuing interest for several reasons. First, the present concepts of the chemical constitution of such important biopolymers as cellulose, amylose, and chitin can be confirmed by their adequate chemical synthesis. Second, synthetic polysaccharides of defined structure can be used to study the action pattern of enzymes, the induction and reaction of antibodies, and the effect of structure on biological activity in the interaction of proteins, nucleic acids, and lipides with polyhydroxylic macromolecules. Third, it is anticipated that synthetic polysaccharides of known structure and molecular size will provide ideal systems for the correlation of chemical and physical properties with chemical constitution and macromolecular conformation. Finally, synthetic polysaccharides and their derivatives should furnish a large variety of potentially useful materials whose properties can be widely varied these substances may find new applications in biology, medicine, and industry. 

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